115 Evolution News Articles
for April 2017
Click on the links below to get the full story from its source
4-28-17 HPV vaccine as cancer prevention is a message that needs to catch on
HPV vaccine as cancer prevention is a message that needs to catch on
New infection stats should be ‘a wake-up call’ to spur lagging vaccination rates. In the United States, HPV vaccination rates lag for girls and boys. The message that the vaccine prevents cancer isn’t getting out there, researchers say. Cancer prevention isn’t the first thing that comes to many parents’ minds when they consider vaccinating their preteens against human papillomavirus, or HPV. And the fact that HPV is transmitted sexually gives the vaccine more baggage than a crowded international flight. But what gets lost in the din is the goal of vaccination, to protect adolescents from infection with HPV types that are responsible for numerous cancers. Newly released estimates show just how prevalent HPV infections are in the United States. In April, the U.S. Centers for Disease Control and Prevention reported for 2013-2014 that among adults ages 18 to 59, 25 percent of men and 20 percent of women had genital infections with HPV types that put them at risk of developing cancer. That’s just a snapshot in time. For those who are sexually active, more than 90 percent of men and 80 percent of women can expect to become infected with at least one type of HPV during their lives. About half of those infections will be with a high-risk HPV type.
4-28-17 Nerve cell miswiring linked to depression
Nerve cell miswiring linked to depression
Mouse study identifies gene needed for proper assembly of serotonin circuitry. In a healthy mouse, nerve cells that release serotonin extend through the hippocampus. But when a specific gene is knocked out, those nerve cell wires clump together. Researchers have pinpointed a gene that keeps important brain cells in mice from crossing their wires, providing a possible link between brain wiring and mood disorders like depression. Without the gene, called Pcdhac2, mice acted more depressed, researchers report April 28 in Science. Nerve cells, or neurons, that produce the chemical messenger molecule serotonin extend long projections called axons to various parts of the brain. Serotonin released from the tips of the axons signal other neurons in these target areas to influence mood and other aspects of behavior. For efficient signaling, the axon tips must be properly spaced. In the new work, scientists from New York City, St. Louis and China found that such spacing is disrupted in mice lacking the Pcdhac2 gene. As a result, serotonin-signaling circuits are not properly assembled and the mice exhibited behaviors indicating depression.
4-28-17 Lungs enlist immune cells to fight infections in capillaries
Lungs enlist immune cells to fight infections in capillaries
Neutrophils are quick in combatting bloodstream pathogens, study in mice finds. Neutrophils crawl along the walls of capillaries in a mouse lung . In mice deficient in a key protein, these immune cells couldn’t move as far as those in mice that had the protein. Immune cells in the lungs provide a rapid counterattack to bloodstream infections, a new study in mice finds. This surprising discovery pegs the lungs as a major pillar in the body’s defense during these dangerous infections, the researchers say. “No one would have guessed the lung would provide such an immediate and strong host defense system,” says Bryan Yipp, an immunologist at the University of Calgary in Canada. Yipp and his colleagues report their findings online April 28 in Science Immunology. The work may offer ways to target and adjust our own immune defense system for infections, says Yipp. “Currently, we only try to kill the bacteria, but we are running out of antibiotics because of resistance.” The research uncovers some of the mechanisms that drive the rapid activation of neutrophils, says immunologist Andrew Gelman of Washington University School of Medicine in St. Louis. “This is critical in removing bacteria from sequestered spaces in the lung,” he says.
4-28-17 Measles, mumps come back
Measles, mumps come back
Measles and mumps are vaccine-preventable diseases that once seemed all but eradicated. But now these highly contagious viral infections are enjoying a resurgence in the U.S., where herd immunity—when enough people are immunized to protect the whole population—is on the decline, thanks in part to the anti-vaccination movement. Texas health officials report the number of mumps cases in the state just hit a 22-year high; so far this year, 221 people have been diagnosed with the virus, which can lead to deafness, brain inflammation, and other complications. Mumps can be prevented with the MMR vaccine, which also protects against measles and rubella, but the recommended two doses are only 88 percent effective against the virus. Immunity against mumps also wanes over time. Recurring outbreaks have prompted the Centers for Disease Control and Prevention to consider a third routine dose of the vaccine. Safety concerns about the MMR vaccine, however, have also allowed measles, which can cause lung and brain damage, to make a comeback. “Because some parents are withholding their children from vaccination,” infectious disease specialist William Schaffner tells MedicalNewsToday.com (Webmaster's comment: Unvaccinated people and children are ignorant disease carriers.)
4-28-17 Runners live longer
Runners live longer
Running for two hours a week could add about three years to your life, a new study suggests. Analyzing existing literature on the link between exercise and longevity, a research team found that running at any pace is associated with an up to 40 percent lower risk for premature death, The New York Times reports. The researchers suspect that running reduces common risk factors, including high blood pressure and extra body fat, but say it’s also possible that runners are more likely to have other healthy habits, such as eating healthfully and not smoking. For reasons that aren’t clear, the benefits of other forms of exercise, such as walking and biking, weren’t as striking, accounting for a roughly 12 percent drop in risk of early death. Overall, most people who laced up their sneakers for two hours weekly would end up running nearly six months over the course of 40 years. The researchers calculated this would result in a net gain of about 2.8 years. The longevity benefits continue to climb up to a peak of about four hours of running a week, researchers said.
4-28-17 Connection can breed contempt
Connection can breed contempt
The global village, it turns out, “is a nasty place,” said Nicholas Carr. Mark Zuckerberg and the other digital zealots have long promised that bringing humanity together in a giant communications network would create “a more harmonious world.” But rather than triggering “a planetary outbreak of peace, love, and understanding,” Facebook, Twitter, Snapchat, and other internet communities have splintered the U.S. and the Western world into angry factions, and filled public discourse with “vitriol and insult.” This actually shouldn’t surprise us: Social research has found abundant evidence that the more close contact we have with other people, the more we become irritated by their different ideas, preferences, and habits. Indeed, the constant avalanche of online self-disclosure can create “an oppressive sense of ‘digital crowding,’” British researchers have found—making people prone to lashing out at those who overshare. The internet’s faceless mode of interaction also serves as a lure to antisocial sadists who enjoy inflicting psychic pain. More than two decades into the internet revolution, we now know that “technology is an amplifier” for humanity’s worst traits as well as our best. “What it doesn’t do is make us better people.”
4-28-17 DNA of extinct humans found in caves
DNA of extinct humans found in caves
The DNA of extinct humans can be retrieved from sediments in caves - even in the absence of skeletal remains. Researchers found the genetic material in sediment samples collected from seven archaeological sites. The remains of ancient humans are often scarce, so the new findings could help scientists learn the identity of inhabitants at sites where only artefacts have been found. The results are described in Science. Antonio Rosas, a scientist at Spain's Natural Science Museum in Madrid, said: "This work represents an enormous scientific breakthrough. "We can now tell which species of hominid occupied a cave and on which particular stratigraphic level, even when no bone or skeletal remains are present."
4-27-17 Mud DNA means we can detect ancient humans even without fossils
Mud DNA means we can detect ancient humans even without fossils
We can now look for ancient human DNA at sites with no bone remains – and perhaps confirm claims such as that humans were present in the Americas 130,000 years ago. We have an astonishing new way to study our early human ancestors: looking for their DNA in ancient sediments in places such as caves. A team of researchers has found the DNA of Neanderthals and Denisovans in some of the sites where they are known to have lived. “I think we show convincingly that these sequences are authentic,” says lead author Viviane Slon of the Max Planck Institute for Evolutionary Anthropology in Germany. The approach can now be used to find out whether early humans were present even when no bones have been found – and what kind of humans they were. It might also help resolve the debate about when the Americas were first inhabited by people, for instance. Just about any sample of soil or water is full of DNA from all kinds of organisms. Sequencing this “environmental DNA” is an increasingly powerful tool for studying ecosystems. For instance, biologists were recently able to identify several caves where “baby dragons”, or olms, live simply by analysing the water flowing out of them. In sediments buried in cool caves and in permafrost, this environmental DNA can survive for up to 700,000 years. In 2003, a team led by Eske Willerslev, now at the University of Cambridge, was the first to show that it was possible to find ancient DNA from species like the woolly mammoth, in frozen mud in Siberian permafrost.
4-27-17 Ancient DNA bucks tale of how the horse was tamed
Ancient DNA bucks tale of how the horse was tamed
Modern-day breeding, not domestication, winnowed genetic diversity. Mongolian horses and other present-day horse breeds have less genetic diversity than domesticated horses did around 2,000 years ago. DNA from 2,000-year-old stallions is helping rewrite the story of horse domestication. Ancient domesticated horses had much more genetic diversity than their present-day descendants do, researchers report in the April 28 Science. In particular, these ancient horses had many more varieties of Y chromosomes and fewer harmful mutations than horses do now. Previous studies based on the genetics of modern horses concluded that domestication must have squeezed out much of the diversity seen in wild horses before the Ice Age. But the new findings suggest that the lack of diversity is a more recent development. “Today, Y chromosomes of all horses are pretty much the same,” says evolutionary geneticist Ludovic Orlando of the Natural History Museum of Denmark in Copenhagen. As a result, scientists thought that ancient people started domesticating horses by breeding only a few stallions to many different mares.
4-27-17 Addicted to love? Craving comes in two forms, and both can hurt
Addicted to love? Craving comes in two forms, and both can hurt
The idea that people can be addicted to love is contentious, but a review of 64 studies found evidence for two different but harmful forms of this condition. You can’t eat, you can’t sleep and all you can think about is your next fix. You may be addicted to love. Intense romance can often come with symptoms resembling addiction – euphoria, craving, dependence, withdrawal and relapse – and brain scans have shown that it can be linked to drug-addiction-like activity in the brain’s reward centres. But the idea that people can be addicted to love is contentious. “It gets complicated because people disagree on the correct theory of addiction, and people especially disagree about what we mean when we use the term ‘love’ ”, says Brian Earp, at the Oxford University Centre for Neuroethics. “I think it is when you realise you do not want to be in love yet cannot avoid it, and it causes bad things, like abuse, that we cross the line into something addiction-like,” says Anders Sandberg, also at the Oxford University Centre for Neuroethics. Now Earp and his team have found evidence that there are in fact two different types of love addiction, after reviewing 64 studies of love and addiction published between 1956 and 2016.
4-27-17 Zika hides out in body’s hard-to-reach spots
Zika hides out in body’s hard-to-reach spots
In rhesus monkeys, virus detected in cerebrospinal fluid, lymph nodes long after infection. Zika virus remains in the central nervous system much longer than it does in the bloodstream, which could help explain its effects on the brain. Weeks after the virus disappears from the bloodstream, it still lingers in the lymph nodes and the central nervous system of rhesus monkeys, researchers report online April 27 in Cell. That could help explain why Zika infection can cause neurological problems in both infants and adults. “Zika does stick around for a lot longer than we originally thought,” says Dan Streblow, a virologist at Oregon Health & Science University in Portland who wasn’t involved in the study. Streblow’s lab recently reported in PLOS Pathogens that Zika can also linger in rhesus monkeys’ reproductive tracts and peripheral nervous systems. And recent studies in humans have shown evidence of the virus hanging around in semen (SN Online: 2/14/17). Now, it appears the central nervous system and lymph nodes are also long-term hiding places. That persistence could help explain why Zika “does substantial damage in the central nervous system,” says Dan Barouch, a study coauthor and virologist at Harvard Medical School. Infection in utero can cause microcephaly in infants, for instance, and the virus has been linked to an increased risk for a neurological autoimmune disease called Guillain-Barré syndrome in adults (SN: 4/2/16, p. 29).
4-27-17 How scientists are turning mosquitos against each other in Florida
How scientists are turning mosquitos against each other in Florida
ientists in Florida have begun an ambitious experiment — one aiming to turn Zika virus-carrying mosquitoes into their own worst enemy. As reported by the AP, Kentucky-based company MosquitoMate has been given the green light to hand off its specially raised male mosquitoes to the Florida Keys Mosquito Control District. Recently, the District released 20,000 of them into a small section of Stock Island along 20 locations; a process they will repeat twice a week for 12 weeks. The mosquitoes have been intentionally infected with the certain strain of a bacterial parasite called Wolbachia, which dampens their ability to breed with wild females who don't carry a compatible Wolbachia strain. It's hoped these mosquitoes will intermingle with the local female population, who will then lay eggs that never hatch, wiping out the next generation without a single spray of chemical pesticide. That will in turn indirectly lower the risk that these mosquitoes can spread viral diseases that have begun to hit the state in recent years, like Zika and chikungunya.
4-27-17 Female dragonflies fake sudden death to avoid male advances
Female dragonflies fake sudden death to avoid male advances
You could almost say they are drop-dead gorgeous: when certain female dragonflies are pursued by unwanted suitors, they deter them by crashing to the ground. Female dragonflies use an extreme tactic to get rid of unwanted suitors: they drop out the sky and then pretend to be dead. Rassim Khelifa from the University of Zurich, Switzerland, witnessed the behaviour for the first time in the moorland hawker dragonfly (Aeshna juncea). While collecting their larvae in the Swiss Alps, he watched a female crash-dive to the ground while being pursued by a male. The female then lay motionless on her back. Her suitor soon flew away, and the female took off once the coast was clear. “I was surprised,” says Khelifa, who had never previously seen this in 10 years of studying dragonflies. Female moorland hawkers are vulnerable to harassment when they lay their eggs since, unlike some other dragonflies, they aren’t guarded by their male mates. A single sexual encounter with another male is enough to fertilise all eggs and copulating again could damage their reproductive tract. Khelifa found that the females often retreat to dense vegetation near ponds at this time, probably to hide. And they often act dramatically when they emerge.
4-27-17 The scales of the ocellated lizard are surprisingly coordinated
The scales of the ocellated lizard are surprisingly coordinated
Lizard grows into its flashy skin using a computer-like process. The green and black spots on the back of an ocellated lizard are arranged according to the rules of a cellular automaton, a concept from computer science. Scales flip colors depending on the colors of their neighbors. A lizard’s intricately patterned skin follows rules like those used by a simple type of computer program. As the ocellated lizard (Timon lepidus) grows, it transforms from a drab, polka-dotted youngster to an emerald-flecked adult. Its scales first morph from white and brown to green and black. Then, as the animal ages, individual scales flip from black to green, or vice versa. Biophysicist Michel Milinkovitch of the University of Geneva realized that the scales weren’t changing their colors by chance. “You have chains of green and chains of black, and they form this labyrinthine pattern that very clearly is not random,” he says. That intricate ornamentation, he and colleagues report April 13 in Nature, can be explained by a cellular automaton, a concept developed by mathematicians in the 1940s and ’50s to simulate diverse complex systems.
4-27-17 How a mushroom gets its glow
How a mushroom gets its glow
Biologists are working out the steps to fungal bioluminescence. A naturally bioluminescent mushroom has a usefully easy-going enzyme that might inspire new glow-in-the-dark labels. The enzyme that turns on the light for a glow-in-the-dark mushroom seems “promiscuous,” researchers say. But in a good way. Researchers from Brazil, Russia and Japan have worked out new details of how two Neonothopanus fungi shine softly green at night. The team had earlier figured out that the basic starting material for bioluminescence in these fungi is a compound called hispidin, found in some other fungi as well as plants such as horsetails. Those plants don’t spontaneously give off light, but in the two Neonothopanus mushroom species studied, an enzyme rejiggers a form of hispidin into a compound that glows. The enzyme that turns a fungus into a natural night-light isn’t that fussy as enzymes go, says Cassius V. Stevani of the University of São Paulo in Brazil. He and colleagues can tweak the enzyme’s natural partner and still get a glow.
4-27-17 First Americans claim sparks controversy
First Americans claim sparks controversy
A study that claims humans reached the Americas 130,000 years ago - much earlier than previously suggested - has run into controversy. Humans are thought to have arrived in the New World no earlier than 25,000 years ago, so the find would push back the first evidence of settlement by more than 100,000 years. The conclusions rest on analysis of animal bones and tools from California. But many experts contacted by the BBC said they doubted the claims. Thomas Deméré, Steven Holen and colleagues examined material from the Cerutti Mastodon site near San Diego. The site was originally uncovered in 1992, during highway construction work. Possible stone tools were discovered alongside the smashed up remains of a mastodon (Mammut americanum) - an extinct relative of mammoths and living elephants. The researchers behind the latest study were unable to carry out radiocarbon dating on the remains, so they used a technique called uranium-thorium dating on several bone fragments, coming up with a date of 130,000 years. The team members found that some of the bones and teeth bore a characteristic breakage pattern known as spiral fracturing, considered to occur when the bone is fresh. Additionally, some of the bones showed typical signs of being smashed with hard objects. Rocks found alongside the mastodon remains show signs of wear and being struck against other surfaces, the researchers say. They conclude that these represent hammerstones and anvils - two types of stone tool used by prehistoric cultures around the world.
4-26-17 First Americans may have been Neanderthals 130,000 years ago
First Americans may have been Neanderthals 130,000 years ago
If the finding from butchered mastodon bones stands up to scrutiny, it could change everything we thought we knew about the earliest humans in the Americas. An extraordinary chapter has just been added to the story of the First Americans. Finds at a site in California suggest that the New World might have first been reached at least 130,000 years ago – more than 100,000 years earlier than conventionally thought. If the evidence stacks up, the earliest people to reach the Americas may have been Neanderthals or Denisovans rather than modern humans. Researchers may have to come to terms with the fact that they have barely scratched the surface of the North American archaeological record. “We often hear statements in the media that a new study changes everything we knew,” says Chris Stringer at the Natural History Museum in London. “If this result stands up to scrutiny, it does indeed change everything we thought we knew about the earliest human occupation of the Americas.” The evidence comes from a coastal site in San Diego County, California. In the early 1990s, routine highway excavations exposed fossil bones belonging to a mastodon, an extinct relative of the elephant. Researchers moved in to examine the site, and they soon decided that this was no ordinary mastodon fossil.
4-26-17 First settlers reached Americas 130,000 years ago, study claims
First settlers reached Americas 130,000 years ago, study claims
Mastodon bones, stone tools place unknown Homo species in California surprisingly early. An unidentified Homo species pounded apart mastodon bones with large stones in southern California around 130,700 years ago, a controversial study concludes. Finds at what’s proposed as the oldest archaeological site in the Americas include this mastodon leg bone with a notch possibly produced by a pounding stone. The New World was a surprisingly old destination for humans or our evolutionary relatives, say investigators of a controversial set of bones and stones. An unidentified Homo species used stone tools to crack apart mastodon bones, teeth and tusks approximately 130,700 years ago at a site near what’s now San Diego. This unsettling claim upending the scientific debate over the settling of the Americas comes from a team led by archaeologist Steven Holen of the Center for American Paleolithic Research in Hot Springs, South Dakota, and paleontologist Thomas Deméré of the San Diego Natural History Museum. If true, it means the Cerutti Mastodon site contains the oldest known evidence, by more than 100,000 years, of human or humanlike colonists in the New World, the researchers report online April 26 in Nature. Around 130,000 years ago, the researchers say, a relatively warm and wet climate would have submerged any land connection between northeastern Asia and what’s now Alaska. So ancient colonizers of North America must have reached the continent in canoes or other vessels and traveled down the Pacific coast, they propose.
4-26-17 Defying dementia: It is not inevitable
Defying dementia: It is not inevitable
Growing older doesn’t necessarily mean you’ll get dementia. Cases are rising as more of us live longer, but the reasons are debated and you can fight back. DEMENTIA isn’t inevitable. The human brain can stay sharp well past 100 years of life. Yes, getting older slows us down: parts of the brain associated with memory and executive function shrink, myelin sheaths around our neurons start to erode, slowing down signalling, and arteries narrow diminishing blood supply. But those things mainly affect speed: when healthy older people are given extra time to perform cognitive tasks, the results are on par with younger folks.In contrast, dementia alters the cognitive playing field. As well as affecting memory, it causes issues with understanding or expressing oneself in language, problems with sensory perception, and disturbances in executive function that can undermine day-to-day independence. Genes play an important part in many kinds of dementia. If you have a parent or sibling with it, you are more likely to develop it yourself. More than 20 different gene variants are now known to influence susceptibility. The various conditions give rise to similar symptoms by different means. Vascular dementia, for instance, can result when cardiovascular disease or a stroke limits blood supply and damages brain tissue. Alzheimer’s disease, the most common cause of dementia, is characterised by a build-up of hard plaques of beta-amyloid protein between brain cells, and tangles of tau protein within them. The amyloid hypothesis, the leading idea for how these plaques drive cognitive decline, suggests that a build-up of plaques causes inflammation in the brain, which spurs development of tau, which disables and then kills brain cells, resulting in memory loss, confusion and other symptoms.
4-26-17 Defying dementia: How to keep your brain fighting fit
Defying dementia: How to keep your brain fighting fit
The number of people with dementia in the US, UK and other wealthy nations has gone down in recent years – a healthy lifestyle can make a difference. THE number of people affected by dementia may be rising, but most specialists say that’s largely because more of us are living longer. Between the late 1980s and 2011, the proportion of people over 65 with dementia actually dropped by 20 per cent in England and Wales. Between 2000 and 2012, dementia rates in that age group dropped by 24 per cent in the US. Similar declines have been reported in other developed countries. There are two driving factors, says Kenneth Langa at the Michigan Center on the Demography of Aging, who tracked the US trend: a rise in educational attainment and better control of cardiovascular issues. After the second world war, there was an increase in schooling that averaged out to about an extra year of education across the US population. Research suggests that people with more education, or those who have done things like learn a new language or learn to play a musical instrument, may be resilient to symptoms of dementia. That doesn’t mean they escape the ravages of vascular dementia or plaques of Alzheimer’s, but they may cope better with the damage. “By challenging your brain during education, you create a more fit brain that can compensate for problems that you have as you age,” Langa says. Increased cognitive reserve is thought to help in two ways: boosting the brain’s ability to work around damaged areas, and promoting more efficient processing. That might also explain why people with more education seem to decline so rapidly: it’s not that Alzheimer’s comes on suddenly, it’s that by the time symptoms manifest the disease may already be quite advanced.
4-26-17 Your inner hoarder: Why letting go is so hard to do
Your inner hoarder: Why letting go is so hard to do
We all know that decluttering is cathartic, so why are our lives still full of junk? The paradoxical world of hoarding disorder has some answers. Amassing more than 150 tonnes of stuff, including 14 grand pianos, the Collyers became a notorious example of hoarding. But if the craze for decluttering tells us anything, it’s that many of us find it difficult to throw things away. Despite the feeling of catharsis that dumping our junk can bring, our possessions often outgrow our homes: around 10 per cent of US families, for example, rent a unit in one of the country’s nearly 53,000 self-storage facilities. And for up to one in 20 of us, hoarding is a diagnosable psychological disorder. But you needn’t be sleeping on newspapers or wading through piles of clothes to have experienced the pain of letting go. Why can it hurt so much to get rid of stuff you will never need again? Researchers investigating what’s going on inside the minds of people with hoarding disorder.
4-26-17 All mammals big or small take about 12 seconds to defecate
All mammals big or small take about 12 seconds to defecate
A study of defecation finds that all mammals take around the same amount of time to relieve themselves. If it’s taking much longer, you may need to see a doctor. Everyone poops, and it takes them about the same amount of time. A new study of the hydrodynamics of defecation finds that all mammals take 12 seconds on average to relieve themselves, no matter how large or small the animal. The research, published in Soft Matter, reveals that the soft matter coming out of the hind ends of elephants, pandas, warthogs and dogs slides out of the rectum on a layer of mucus that keeps toilet time to a minimum. “The smell of body waste attracts predators, which is dangerous for animals. If they stay longer doing their thing, they’re exposing themselves and risking being discovered,” says Patricia Yang, a mechanical engineer at the Georgia Institute of Technology in Atlanta. Yang and colleagues filmed elephants, pandas and warthogs at a local zoo, and one team member’s dog in a park, as they defecated. Though the animals’ body masses ranged from 4 to 4,000 kilograms, the duration of defecation remained constant.
4-26-17 Long naps lead to less night sleep for toddlers
Long naps lead to less night sleep for toddlers
Late afternoon naps can push back bedtime, but naps probably don’t affect the total amount of sleep a toddler gets in a 24-hour period, a study suggests. Like most moms and dads, my time in the post-baby throes of sleep deprivation is a hazy memory. But I do remember feeling instant rage upon hearing a popular piece of advice for how to get my little one some shut-eye: “sleep begets sleep.” The rule’s reasoning is unassailable: To get some sleep, my baby just had to get some sleep. Oh. So helpful. Thank you, lady in the post office and entire Internet. So I admit to feeling some satisfaction when I came across a study that found an exception to the “sleep begets sleep” rule. The study quite reasonably suggests there is a finite amount of sleep to be had, at least for the 50 Japanese 19-month-olds tracked by researchers. The researchers used activity monitors to record a week’s worth of babies’ daytime naps, nighttime sleep and activity patterns. The results, published June 9, 2016, in Scientific Reports, showed a trade-off between naps and night sleep. Naps came at the expense of night sleep: The longer the nap, the shorter the night sleep, the researchers found. And naps that stretched late into the afternoon seemed to push back bedtime.
4-26-17 Pollution nanoparticles may enter your blood and cause disease
Pollution nanoparticles may enter your blood and cause disease
A study of airborne nanoparticles – which are nearly impossible to measure in our air - may explain why pollution is linked to heart attacks and strokes. You won’t breathe easy after reading this: a few of the nanoparticles in the air you are inhaling are entering your bloodstream and building up in the diseased areas of your arteries. This finding could help explain why air pollution raises the risk of heart disease and strokes. But what’s really worrying is that it suggests that current laws and efforts to regulate air pollution are focusing on the wrong particles. “We are potentially looking in the wrong place,” says David Newby at the University of Edinburgh, UK. Numerous studies have shown that air pollution leads to millions of premature deaths worldwide each year. Even in Europe, with its relatively clean air, air pollution is blamed for 400,000 premature deaths a year. Most of these deaths are due to the raised risk of cardiovascular disease: simply being exposed to high pollution for short periods can trigger heart attacks and strokes, while long-term exposure causes vascular damage. The big question is why. It has long been suspected that some of the nanoparticles we breathe in could get into the bloodstream and damage blood vessels, but until now, this had never been shown. These nanoparticles are mostly carbon compounds, and finding them inside carbon-based lifeforms like ourselves is extremely difficult.
4-25-17 The mind-altering power of doubt
The mind-altering power of doubt
Doubt is an incredible mental tool. But it's also dangerously easily to manipulate. She had visited Madonna's mansion the week before, Maggie told me during my ward round. Helped her choose outfits for the tour. The only problem was that Maggie was a seamstress in Dublin. She had never met Madonna; she had never provided her with sartorial advice on cone brassieres. Instead, an MRI scan conducted a few days earlier — when Maggie arrived at the ER febrile and agitated — revealed encephalitis, a swelling of the brain. Now she was confabulating, conveying false memories induced by injury to her brain. Not once did Maggie doubt that she was a seamstress to the stars, no matter how incongruous those stories seemed. And that's the essence of confabulation: The critical faculty of doubt is compromised. These honest lies were Maggie's truth. In its most extreme form, confabulation emerges from brain damage caused by encephalitis, strokes, trauma, or thiamine deficiency caused by chronic alcohol dependence. Some confabulators with these conditions produce bizarre fabrications: they recount past lives as spaceship captains or report aliens on UFOs. Confabulators with an underlying brain injury often try to act upon fantastical tales — insisting on reaching a celebrity mansion with a sewing machine. Remote memories and perceptions drift into the present; conflated, scrambled, and irrelevant to the here and now.
4-25-17 Family tree of dogs reveals secret history of canines
Family tree of dogs reveals secret history of canines
The largest family tree of dogs ever assembled shows how canines evolved into more than 150 modern breeds. Dogs were first selected and bred for their ability to perform tasks such as herding goats or cattle, say scientists. Later, they were selected for physical features such as their size or colour. The study also unearths evidence that some dogs are descended from an ancient breed that travelled with the ancestors of Native Americans into the Americas. Archaeological evidence points to the so-called "New World dog", which apparently crossed with human settlers over a land bridge from Asia. It had previously been thought that all signs of this ancient breed had been erased as dogs bred in Europe spread around the world. "We think there is still some signature of New World dog hiding in the genome of some of these American breeds," said co-researcher Heidi Parker of the National Institutes of Health, US. Modern hairless breeds such as the Peruvian hairless dog and the Mexican hairless dog are likely descended from this ancient dog.
4-25-17 Homo naledi’s brain shows humanlike features
Homo naledi’s brain shows humanlike features
Mysterious hominid had neural features associated with social emotions and communication, researchers claim. A virtual cast of Homo naledi’s brain surface contains clues to the presence of a region that may correspond to Broca’s area in present-day people. This language-related neural region enhanced social emotions and communication in the still-undated southern African Homo species, researchers contend. A relatively small brain can pack a big evolutionary punch. Consider Homo naledi, a famously puzzling fossil species in the human genus. Despite having a brain only slightly larger than a chimpanzee’s, H. naledi displays key humanlike neural features, two anthropologists reported April 20 at the annual meeting of the American Association of Physical Anthropologists. Those brain characteristics include a region corresponding to Broca’s area, which spans parts of the right and left sides of the brain in present-day people. The left side is typically involved in speech and language. “It looks like Homo naledi’s brain evolved a huge amount of shape change that supported social emotions and advanced communication of some type,” said Shawn Hurst of Indiana University Bloomington, who presented the new findings. “We can’t say for sure whether that included language.” Frontal brain locations near Broca’s area contribute to social emotions such as empathy, pride and shame. As interactions within groups became more complex in ancient Homo species, neural capacities for experiencing social emotions and communicating verbally blossomed, Hurst suspects.
4-25-17 Homo naledi is only 250,000 years old – here’s why that matters
Homo naledi is only 250,000 years old – here’s why that matters
The latest species of extinct hominin to be discovered that promised to rewrite our history may have died out as modern humans came about. In 2013, Lee Berger at the University of the Witwatersrand in Johannesburg and his colleagues made an extraordinary discovery – deep inside a South African cave system they found thousands of bones belonging to a brand new species of early human — and now we finally may know when this species lived and how it fits into our evolutionary tree. By 2015 it was becoming clear that the new species, which was named Homo naledi, was unlike anything researchers had discovered before. Although parts of its skeleton looked identical to our modern human anatomy, it had some features that were strikingly primitive – including a skull that was only slightly larger than that of a chimpanzee. But Berger and his colleagues had trouble establishing how old the H. naledi fossils were. Without that piece of information, most other researchers agreed that the true significance of H. naledi for understanding human evolution was unclear. Guesses have varied from as old as 2 million years to as young as 100,000 years. Today, news broke that Berger’s team has finally found a way to date the fossils. In an interview published by National Geographic magazine, Berger revealed that the H. naledi fossils are between 300,000 and 200,000 years old. “This is astonishingly young for a species that still displays primitive characteristics found in fossils about 2 million years old, such as the small brain size, curved fingers, and form of the shoulder, trunk and hip joint,” says Chris Stringer at the Natural History Museum in London.
4-25-17 Primitive human 'lived much more recently'
Primitive human 'lived much more recently'
A primitive type of human, once thought to be up to three million years old, actually lived much more recently, a study suggests. The remains of 15 partial skeletons belonging to the species Homo naledi were described in 2015. They were found deep in a cave system in South Africa by a team led by Lee Berger from Wits University. In an interview, he now says the remains are probably just 200,000 to 300,000 years old. Although its anatomy shares some similarities with modern people, other anatomical features of Homo naledi hark back to humans that lived in much earlier times - some two million years ago or more. "These look like a primitive form of our own genus - Homo. It looks like it might be connected to early Homo erectus, or Homo habilis, Homo rudolfensis," said Prof Berger's colleague, John Hawks, from the University of Wisconsin. Although some experts guessed that naledi could had lived relatively recently, in 2015, Prof Berger told BBC News that the remains could be up to three million years old. New dating evidence places the species in a time period where Homo naledi could have overlapped with early examples of our own kind, Homo sapiens. Prof Hawks told the BBC's Inside Science radio programme: "They're the age of Neanderthals in Europe, they're the age of Denisovans in Asia, they're the age of early modern humans in Africa. They're part of this diversity in the world that's there as our species was originating."
4-25-17 Should you be massaging your baby?
Should you be massaging your baby?
Expectant and new parents love to know exactly what baby gear they should be buying. People are eager to make suggestions: the best swings, the right carriers, the MamaRoo, the Rock n' Play, the Miracle Blanket, all "guaranteed" to soothe your kiddo. But here's one suggestion you probably don't hear very often: infant massage. It may sound "out there" — and maybe I'm biased because I live in Los Angeles — but there's a lot of research supporting the benefits of this calming technique. But what, exactly, is baby massage? Surely we can't just give our kiddos a rigorous rubdown, right? Infant massage is seen as a form of therapy across the world, and a bonding method between parent and baby. It's usually done during the first year of a child's life and involves gently rubbing and kneading the baby's body. There are two styles: Indian, which is rigorous, and Western, which is a bit more gentle. In the U.S., parents also use infant massage to ease common problems like colic and gas pains. Research also suggests it can help with weight gain, sleep, and bonding and intellectual development. It can even help ease postpartum depression in new mothers.
4-25-17 Hungry stomach hormone promotes growth of new brain cells
Hungry stomach hormone promotes growth of new brain cells
Some people say that fasting makes them feel mentally sharper. The hunger hormone ghrelin may be why – and it may protect against Parkinson’s disease. Could fasting boost your brainpower? A stomach hormone that stimulates appetite seems to promote the growth of new brain cells and protect them from the effects of ageing – and may explain why some people say that fasting makes them feel mentally sharper. When ghrelin was first discovered, it became known as the hunger hormone. It is made by the stomach when it gets empty, and whenever we go a few hours without food its levels rise in our blood. But there is also evidence that ghrelin can enhance cognition. Animals that have reduced-calorie diets have better mental abilities, and ghrelin might be part of the reason why. Injecting the hormone into mice improves their performance in learning and memory tests, and seems to boost the number of neuron connections in their brains. Now Jeffrey Davies at Swansea University, UK, and his team have found further evidence that ghrelin can stimulate brain cells to divide and multiply, a process called neurogenesis. When they added the hormone to mouse brain cells grown in a dish, it switched on a gene known to trigger neurogenesis, called fibroblast growth factor.
4-25-17 Oldest evidence of patterned silk loom found in China
Oldest evidence of patterned silk loom found in China
The technology fed the Silk Road trade. Excavation of a roughly 2,100-year-old tomb in southern China uncovered four small-scale models of pattern looms, including these two shown where they were found alongside several wooden figurines. These discoveries represent the earliest clues to a weaving technique that transformed silk production. An ancient tomb in southern China has provided the oldest known examples, in scaled-down form, of revolutionary weaving machines called pattern looms. Four immobile models of pattern looms illuminate how weavers first produced silk textiles with repeating patterns. The cloths were traded across Eurasia via the Silk Road, Chinese archaeologists report in the April Antiquity. The models, created between 2,200 and 2,100 years ago, predate other evidence of pattern looms by several hundred years. Red and brown silk threads still clung to the model looms. The largest stood half a meter tall. A reconstruction of that model includes two foot pumps connected to beams, shafts and other parts. A full-scale device with moving parts would have woven repeating geometric designs on clothing and other items made of silk, a technique that transformed the textile’s production. These 2013 discoveries, made of wood and bamboo, supply the first direct evidence that pattern looms were invented in ancient China. Such looms are mentioned in ancient Chinese texts, but actual examples of the loom technology were lacking. Pattern looms influenced the design of another type of weaving machine that appeared in China within the next few hundred years and then spread to Persia, India and Europe, the researchers suspect.
4-25-17 'World's oldest fungus' raises evolution questions
'World's oldest fungus' raises evolution questions
Fungus-like life forms have been found in rocks dating back 2.4 billion years. The fossils, drilled from rocks that were once beneath the seafloor, resemble living fungi. Scientists say the discovery could push back the date for the oldest fungi by one to two billion years. The find suggests that fungi arose not on land but in the deep sea. If not a fungus, the organism could be from an extinct branch of life that has not been described before. Prof Stefan Bengtson of the Swedish Museum of Natural History led the research team. He said, in the past, scientists may have been looking in the wrong place for the oldest fossil fungi - on land or in shallow seas rather than in the deep sea. "The deep biosphere (where the fossils were found) represents a significant portion of the Earth, but we know very little about its biology and even less about its evolutionary history," Prof Bengtson told BBC News.
4-24-17 Weird, hairy microbes discovered on volcano soon after eruption
Weird, hairy microbes discovered on volcano soon after eruption
Mysterious mats of bacteria, dubbed Venus’s hair, have been found thriving on a volcano near the Canary Islands after it erupted and wiped out other living things. Gone today, hair tomorrow. Soon after an underwater volcano erupted and wiped out all nearby life forms, hardy bacteria moved in and covered the area in a huge mat of hair-like filaments. These strange colonies were found by an expedition to Tagoro Volcano, near the Canary Islands, in 2014, two years after an eruption that reshaped 9 square kilometres of the sea floor. The researchers explored the area via a robotic submarine equipped with cameras and arms for collecting samples. “Something very strange appeared to us: a very nice picturesque coverage of very long white filaments which were very unusual. It was the first time we had seen something like that,” says Roberto Danovaro of the Polytechnic University of Marche, Italy. They named the organism Venus’s hair, recalling Botticelli’s painting of the goddess Venus emerging from the sea. Genetic analysis showed that it was very different from any other known microbes. Most striking, Danovaro says, were the huge portfolio of metabolic functions enabling the bacteria to grow in such a hostile environment. In particular, most organisms would be killed by the hydrogen sulphide coming out of the rocks, but instead it is an energy source for Venus’s hair, just like bacteria that grow around hydrothermal vents.
4-24-17 Beetles have been mooching off insect colonies for millions of years
Beetles have been mooching off insect colonies for millions of years
99-million-year-old amber shows two species that pilfered from ancient ants and termites. Some ancient beetles survived by freeloading off social insects such as termites. Two new beetle fossils (Cretotrichopsenius burmiticus and Mesosymbion compactus) suggest that the behavior, known as social parasitism, has endured for about 100 million years. Mooching roommates are an ancient problem. Certain species of beetles evolved to live with and leech off social insects such as ants and termites as long ago as the mid-Cretaceous, two new beetle fossils suggest. The finds date the behavior, called social parasitism, to almost 50 million years earlier than previously thought. Ants and termites are eusocial — they live in communal groups, sharing labor and collectively raising their young. The freeloading beetles turn that social nature to their advantage. They snack on their hosts’ larvae and use their tunnels for protection, while giving nothing in return. Previous fossils have suggested that this social parasitism has been going on for about 52 million years. But the new finds push that date way back. The specimens, preserved in 99-million-year-old Burmese amber, would have evolved relatively shortly after eusociality is thought to have popped up.
4-24-17 Mystery human species Homo naledi had tiny but advanced brain
Mystery human species Homo naledi had tiny but advanced brain
The first analyses of skull data from the most recently discovered species of early human suggest that its brain was surprising sophisticated. It’s not the size of your brain, it’s how you organise it. The most recently discovered species of early human had a skull only slightly larger than a chimpanzee’s, but its brain looked surprisingly like our own – particularly in an area of the frontal lobe with links to language. This could back suggestions that these mysterious early humans showed advanced behaviours, such as teamwork and burial, even though we still don’t know exactly when they lived. In 2013, news broke of an extraordinary discovery in a chamber deep inside a South African cave. Researchers led by Lee Berger at the University of the Witwatersrand in Johannesburg had discovered thousands of ancient human fossils – comfortably the largest cache of its kind ever found in Africa. The first official scientific reports were published in 2015, and they painted a confusing picture. The bones belonged to a never-before-seen early human, which was named Homo naledi.
4-21-17 Should you worry about heavy phone use causing cancer?
Should you worry about heavy phone use causing cancer?
An Italian court has ruled that heavy cellphone usage was to blame for a man’s tumour. But there is still no convincing evidence that phones raise cancer risk. Do mobile phones increase the risk of cancer? An Italian court has ruled that heavy cellphone usage caused a man’s benign tumour, but there is still no convincing evidence that mobile phones increase the risk of cancer. The man, Robert Romeo, says he spoke on a mobile phone for around 3 hours a day for 15 years while working for a telecoms company. In 2010, he was diagnosed as having a benign tumour in his right ear, and he lost the hearing in that ear when the tumour was removed. It is understandable that if a person spends years with a cellphone pressed to their ear, they blame the phone if they get a tumour in that ear. But correlation is not causation.
4-21-17 Ötzi the Iceman froze to death
Ötzi the Iceman froze to death
New analyses of mummy show head knocks, arrow wound not lethal. Ötzi the Tyrolean Iceman died of exposure to cold temperatures in the Italian Alps, a new study concludes. Shoulder and head injuries may have made it difficult for the Copper Age hunter-gatherer to get around but that’s not what killed him, researchers say. Ever since Ötzi’s mummified body was found in the Italian Alps in 1991, researchers have been trying to pin down how the 5,300-year-old Tyrolean Iceman died. It now looks like this Copper Age hunter-gatherer simply froze to death, perhaps after suffering minor blood loss from an arrow wound to his left shoulder, anthropologist Frank Rühli of the University of Zurich reported April 20 at the annual meeting of the American Association of Physical Anthropologists. “Freezing to death is quite likely the main cause of death in this classic cold case,” Rühli said. Ötzi succumbed to exposure within anywhere from a few minutes to a few hours, he estimated.
4-21-17 HPV infections rampant
HPV infections rampant
Nearly half of all Americans between 18 and 59 have some strain of genital human papillomavirus (HPV), the Centers for Disease Control and Prevention (CDC) reports, making it the nation’s most common sexually transmitted infection. More than 40 types of HPV are easily spread through direct sexual contact. Some low-risk strains of the virus cause genital warts, but CDC researchers found that 25 percent of men and 20 percent of women have a high-risk strain that can cause cancer of the cervix, vulva, vagina, penis, anus, and throat. Health officials say it’s important for more parents to vaccinate their children against HPV. “If we can get 11- and 12-year-olds to get the vaccine, we’ll make some progress,” CDC epidemiologist Geraldine McQuillan tells The New York Times. “You need to give it before kids become sexually active, before they get infected. This is a vaccine against cancer—that’s the message.”
4-21-17 Aspirin cuts cancer risk
Aspirin cuts cancer risk
Doctors have long prescribed aspirin to ward off heart attacks and strokes, but now a new study suggests low-dose aspirin therapy may also reduce the risk of dying from several forms of cancer. Researchers at Harvard analyzed the aspirin use of about 130,000 adults over a period of 32 years. They found that among people who took aspirin regularly for a minimum of six years, the odds of dying from cancer were 7 percent lower for women and 15 percent lower for men. Aspirin’s effects were most pronounced for people with colon cancer, but routine use of the drug was also associated with a lower risk of death from breast, prostate, and lung cancers, CNN.com reports. What accounts for the results? The study authors suspect aspirin’s anti-coagulant and anti-inflammatory effects may help prevent cancerous cells from growing and spreading throughout the body. Long-term aspirin therapy isn’t for everyone, however, particularly people at high risk for ulcers and gastrointestinal bleeding. “If a person wants to take a low-dose aspirin, especially if a person has had cancer,” says researcher Yin Cao, “they will want to have an initial conversation with their doctor.”
4-21-17 Furry pets, healthier babies
Furry pets, healthier babies
The therapeutic value of pets is well-known, but a new Canadian study takes it to another level, suggesting that women with animals have healthier babies. Researchers asked the mothers of more than 700 children about pets they owned during pregnancy and for three months after delivery. They found that babies exposed to furry animals—especially dogs—have significantly higher levels of Ruminococcus and Oscillospira, two beneficial gut bacteria associated with a lower risk for allergies and obesity, ScienceDaily?.com reports. The researchers explain that pet bacteria enhance a newborn’s resistance to those chronic health issues. Prenatal pet exposure also reduces the risk that mothers will pass vaginal group B strep (GBS)—linked to sepsis, pneumonia, and meningitis—to children during delivery. Eventually, a “dog in a pill” may be developed to help confer these health benefits, predicts study author Anita Kozyrskyj. “It’s not far-fetched that the pharmaceutical industry will try to create a supplement of these microbiomes,” she says, “much like was done with probiotics.”
4-21-17 Mystery human hobbit ancestor may have been first out of Africa
Mystery human hobbit ancestor may have been first out of Africa
The evolutionary origins of the tiny Indonesian hominin Homo floresiensis have perplexed us for years – now there’s a new twist to the tale, suggesting we had it figured out all wrong. The identity of the mysterious Homo floresiensis, aka the hobbit, has once again been turned on its head. New research suggests the tiny hominin evolved from an unknown ancestor that was the first to ever venture out of Africa. Remains of the extinct species were first discovered on the island of Flores in Indonesia just over a decade ago, but there is still fierce debate about where they came from. The dominant idea has been that H. floresiensis was descended from the larger Homo erectus, an extinct human species that once occupied Asia. Proponents believe ancestors of H. erectus were the first humans to stray out of Africa about 1.8 million years ago. The theory is that after members of the big-bodied group reached Flores, they gradually shrunk to just 1 metre tall because of the scarce island resources. Another possibility is that the hobbits were simply short members of our own species – Homo sapiens. The miniature size of the one skull that has been uncovered could be the result of Down syndrome. Now, the most comprehensive analysis yet suggests the hobbits were, in fact, descended from a mystery ancestor that lived in Africa over 2 million years ago. Some members of this ancestral group remained in Africa and evolved into Homo habilis – the first makers of stone tools. The others moved out of Africa about 2 million years ago – before H. erectus did – and arrived in Flores at least 700,000 years ago.
4-20-17 Immune cells play surprising role in steady heartbeat
Immune cells play surprising role in steady heartbeat
Macrophages boost electrical jolt that causes mouse heart muscle cells to contract. Macrophages “plug in” to heart cells, providing an electrical boost that helps the heart cells contract and pump blood, a study in mice finds. Immune system cells may help your heart keep the beat. These cells, called macrophages, usually protect the body from invading pathogens. But a new study published April 20 in Cell shows that in mice, the immune cells help electricity flow between muscle cells to keep the organ pumping. Macrophages squeeze in between heart muscle cells, called cardiomyocytes. These muscle cells rhythmically contract in response to electrical signals, pumping blood through the heart. By “plugging in” to the cardiomyocytes, macrophages help the heart cells receive the signals and stay on beat.
4-20-17 Machine learning shows exactly when to zap brain to boost memory
Machine learning shows exactly when to zap brain to boost memory
Jolting the brain with electricity really does seem to boost memory, but only if it’s done at the right time. Now we can detect when the brain could use a shock. Struggling to remember something? An electrical jolt deep in the brain might help – if it is given at the right time. To discover the effect of electrical stimulation on memory, Michael Kahana and colleagues at the University of Pennsylvania turned to 150 volunteers who had previously had electrodes implanted in their brains to help control severe epilepsy. These electrodes can record the brain’s electrical signals, giving the team a window into each person’s neural processes. They can also deliver electricity to the brain. First, the team recorded the brain signals of the volunteers while they learned items from a list, and later as they tried to recall those items. They then applied machine learning methods to this brain signal data, enabling them to predict if a person’s efforts to commit something to memory would later prove successful, based on the state of their brain at the time. The team next ran further recall tests, during which they delivered random jolts of electricity to the participants while they were trying to memorise test items. They compared the effects of jolting someone during two different brain states – the pattern of signals linked to being likely to later remember something, and the pattern linked to being more likely to have a memory lapse. They found that giving electrical stimulation when a person’s brain signals suggested they would later forget the current item made that person 13 per cent more likely to recall it. “You get significant enhancement,” says Kahana.
4-20-17 Evidence is lacking that ‘cocooning’ prevents whooping cough in newborns
Evidence is lacking that ‘cocooning’ prevents whooping cough in newborns
The cocooning strategy, in which people who will be in contact with a newborn all receive vaccinations to protect the vulnerable baby, may not be that protective after all. Better protection against whooping cough comes from vaccinating a mother during pregnancy, scientists say. Last week, I wrote about how powerfully protective whooping cough vaccines can be when babies receive their first dose before even being born, from their pregnant mothers-to-be. As I was looking through that study, another of its findings struck me: Babies didn’t seem to get any extra whooping cough protection when their moms were vaccinated after giving birth. I wondered if this meant that I was unreasonable when I insisted my parents be fully boosted before visiting their first granddaughter. If post-birth vaccinations aren’t that important for mothers, who are entwined in every way imaginable with their newborns, is it likely that grandparents’ vaccination status is all that important? While it’s a good idea to make sure everyone is current on vaccines, the evidence for cocooning as a way to keep infants healthy has been lacking. “I haven’t seen any studies that show a strong protective effect form the cocooning strategy,” says Nicola Klein, the pediatrician and vaccine researcher who led the recent Pediatrics study on vaccinations for whooping cough.
4-20-17 Unknown ancient reptile roamed the Pyrenees mountains
Unknown ancient reptile roamed the Pyrenees mountains
The footprints of a mysterious reptile that lived about 250 million years ago have been identified in fossils from the Pyrenees mountains. Scientists say the new species is a member of the group that gave rise to crocodiles and dinosaurs. The reptile lived at a time when the Earth was recovering from a mass extinction that wiped out most animals. The discovery may shed light on how the group of animals evolved and spread. About 252 million years ago, a mass extinction devastated life on land and in the oceans. Some 90% of species disappeared. At the time, the Earth was very different from today, with continents grouped into the supercontinent, Pangaea. (Webmaster's comment: The Age of the Dinosaurs was a full blown set of ecosystems with tens of thousands of species of plants and animals. It was just as complex then as today's ecosystems.)
4-20-17 50 years ago, continental drift began to gain acceptance
50 years ago, continental drift began to gain acceptance
Earth’s outer crust is composed of more than a dozen large pieces, known as tectonic plates, which bump or slide against each other. Continental drift, a theory often considered amusing but rarely important, seems about to become the focus of a revolution in geology. At the least, it has already split the geological community into those who find the evidence for it “formidable” and those who think it is not yet formidable enough to constitute a proof. — Science News, April 29, 1967. That continents shift is now widely accepted and explained by plate tectonics. Plenty of evidence supports the idea that the Earth’s outer layer is divided into large slabs that gradually move over the mantle. But researchers don’t agree on when the plates first began shifting. New evidence from ancient rocks found in Canada suggests the slipping and sliding didn’t get going until Earth was at least a billion years old (SN: 4/15/17, p. 8). In about 250 million years from now, the continents may drift together into a supercontinent called Amasia (SN: 1/21/17, p. 18).
4-19-17 Your true self: How your personality changes throughout life
Your true self: How your personality changes throughout life
You are not the person you were as a child, or even last year. The discovery that our characters change is unnerving, but embrace it and it can be empowering. AS A child, Wendy Johnson was extremely shy. “One of my report cards said: ‘Wendy is so shy, it’s painful to watch!” She’s not like that now. “I am definitely a person who learned to overcome overt shyness,” says Johnson, a psychologist at the University of Edinburgh, UK. She says shyness is an indicator of a low level of extroversion, a key measure of personality, which she studies. So does this mean Johnson has changed her personality? Undoubtedly, she says. That answer might surprise you. Most of us consider our personality to be an integral and unchanging part of who we are – perhaps the essence of that thing we call the self. In 1887, psychologist William James went so far as to argue that it becomes “set like plaster” by the age of 30. His idea stuck. Psychologists have long debated how to measure personality, settling eventually on the “big five” traits (see “What are you like?“). But at least they were able to agree on a definition: personality refers to an individual’s thought patterns and behaviours, which tend to persist over time. Now mounting evidence is undermining that notion. Personality is far more mutable than we thought. That may be a little unsettling. But it’s also good news for the almost 90 per cent of us who wish our personalities were at least a little different. There’s no doubt that personality is partly genetic. What’s less certain is how much is down to our genes and how much to nurture. Newborn babies don’t have personalities as such, but do have characteristic ways of behaving and reacting, something psychologists call “temperament”. This includes persistence in the face of setbacks, and “reactivity”. Very reactive babies are shy and avoid novel situations. Temperament is often viewed as the biological basis of personality, but it is far from innate. Genes and environment interact to influence it even before birth. For example, there’s evidence that mothers who are stressed during pregnancy are more likely to have an anxious child. (Webmaster's comment: And how much individually is nurture could well be dependent on your own genetics.)
4-19-17 Blood from human babies makes brains of elderly mice young again
Blood from human babies makes brains of elderly mice young again
Young blood can rejuvenate the mind. Now a study has identified a protein in umbilical cord blood that can boost memory and brain function in aged mice. Do you feel like your brain is getting sluggish with age? A protein found in umbilical cord blood may help restore its youthful vigor. Researchers have previously found that blood from human teenagers can rejuvenate memory and cognition in elderly mice, probably due to factors present in the plasma – the liquid portion of the blood. Now, blood harvested from babies’ umbilical cords has been found to have even stronger anti-ageing effects. Joseph Castellano at Stanford University in California and his colleagues discovered this by collecting blood from people at three different life stages – babies, young people around the age of 22, and older people around the age of 66 – and injecting the plasma component into mice that were the equivalent of around 50 years old in human years. The most dramatic effects occurred when these mice received babies’ cord plasma. They became faster learners and were better at remembering their way through a maze. This corresponded with enhanced activity in their hippocampi – the brain regions responsible for learning and memory. Mice that received young people’s plasma also had modest improvements in hippocampus function, but those that received plasma from older adults showed no such improvement. This suggests that human plasma gradually loses its rejuvenating potential with age.
4-19-17 Brain gains seen in elderly mice injected with human umbilical cord plasma
Brain gains seen in elderly mice injected with human umbilical cord plasma
Memory protein that declines with aging also identified in mouse study. In the hippocampus of a 1-month-old mouse, some nerve cells produce the protein TIMP2 (green), which declines with age and may help keep the brain young. Plasma taken from human umbilical cords can rejuvenate old mice’s brains and improve their memories, a new study suggests. The results, published online April 19 in Nature, may ultimately help scientists develop ways to stave off aging. Earlier studies have turned up youthful effects of young mice’s blood on old mice (SN: 12/27/14, p. 21). Human plasma, the new results suggest, confers similar benefits, says study coauthor Joseph Castellano, a neuroscientist at Stanford University. The study also identifies a protein that’s particularly important for the youthful effects, a detail that “adds a nice piece to the puzzle,” Castellano says.
4-19-17 Drunken crayfish show that loneliness raises alcohol tolerance
Drunken crayfish show that loneliness raises alcohol tolerance
Crayfish forced to be solitary are less affected by alcohol, because being alone appears to alter the way their nerves function. For crayfish at least, a more sociable life makes booze work quicker. When crayfish were put in water containing a little alcohol, the ones who had been kept on their own over the preceding week took longer to show signs of alcohol exposure – such as tail flips – than those who had been living with others of their kind. The researchers then implanted tiny electrodes in the neurons that drive the tail-flip behaviour. They found that in crayfish exposed to alcohol, the intensity of the electrical signal needed to trigger a tail flip was lower – and it dropped further and more quickly in the animals that had had company than in the isolated ones. “This clearly shows a socially induced change in their reaction to alcohol,” says neuroscientist Jens Herberholz at the University of Maryland in College Park. His team chose to study crayfish because it has long been known that their social status affects their behaviour, and also because exposing the animals to alcohol has obvious effects. At first they stand tall on fully extended legs in an aggressive pose, then start to tail flip and finally end up on their back unable to right themselves. So why is this response affected by being solitary or in company? It seems the social environment affects the receptors on nerve cells that respond to neurotransmitters like serotonin, which in turn changes how alcohol affects nerves.
4-19-17 Venomous fish have evolved many ways to inflict pain
Venomous fish have evolved many ways to inflict pain
There may be compounds in fish venoms that have medicinal uses. A venomous reef stonefish (Synanceia verrucosa) is camouflaged as a rock in the Indian Ocean. Stings from the spines of this species are very painful. Biologist Leo Smith held an unusual job while an undergraduate student in San Diego. Twice a year, he tagged along on a chartered boat with elderly passengers. The group needed him to identify two particular species of rockfish, the chilipepper rockfish and the California shortspine thornyhead. Once he’d found the red-orange creatures, the passengers would stab themselves in the arms with the fishes’ spines. Doing so, the seniors believed, would relieve their aching arthritic joints. Smith, now at the University of Kansas in Lawrence, didn’t think much of the practice at the time, but now he wonders if those passengers were on to something. Though there’s no evidence that anything in rockfish venom can alleviate pain — most fish stings are, in fact, quite painful themselves — some scientists suspect fish venom is worth a look. Studying the way venom molecules from diverse fishes inflict pain might help researchers understand how nerve cells sense pain and lead to novel ways to dull the sensation.
4-19-17 Frog slime protein fights off the flu
Frog slime protein fights off the flu
Slime produced by Hydrophylax bahuvistara contains a newly identified flu-fighting protein called urumin, named for a type of sword used in the region of India where the frog resides. The next flu drug could come from frog mucus. It’s not as crazy as it sounds: For decades, scientists have searched for new antiviral drugs by mining proteins that animals produce to protect themselves from microbes. In lab tests, proteins found in amphibian secretions can defend against HIV, herpes and now the flu. David Holthausen of Emory University and his colleagues sampled slime from the skin of Hydrophylax bahuvistara, a recently discovered frog species from southern India. They tested the influenza-fighting ability of 32 slime proteins, and four showed promise. Of those, three proved toxic to mammals. But one peptide, dubbed urumin, showed a propensity for fighting off the flu.
4-19-17 Psychedelic drugs push the brain to a state never seen before
Psychedelic drugs push the brain to a state never seen before
Brain measurements have revealed that LSD, ketamine and psilocybin cause patterns of brain activity that are far more diverse than normal consciousness. Measuring neuron activity has revealed that psychedelic drugs really do alter the state of the brain, creating a different kind of consciousness. “We see an increase in the diversity of signals from the brain,” says Anil Seth, at the University of Sussex, UK. “The brain is more complex in its activity.” Seth and his team discovered this by re-analysing data previously collected by researchers at Imperial College London. Robin Carhart-Harris and his colleagues had monitored brain activity in 19 volunteers who had taken ketamine, 15 who had had LSD, and 14 who were under the influence of psilocybin, a hallucinogenic compound in magic mushrooms. Carhart-Harris’s team used sets of sensors attached to the skull to measure the magnetic fields produced by these volunteer’s neurons, and compared these to when each person took a placebo. “We took the activity data, cleaned it up then chopped it into 2-second chunks,” says Seth, whose team worked with Carhart-Harris on the re-analysis. “For each chunk, we could calculate a measure of diversity.”
4-18-17 Autism, ADHD risk not linked to prenatal exposure to antidepressants
Autism, ADHD risk not linked to prenatal exposure to antidepressants
Two new large studies may provide reassurance to pregnant women with depression. Pregnant women coping with depression now may have one less thing to worry about: Prenatal exposure to antidepressants doesn’t raise autism risk, two new studies suggest. Taking antidepressants during pregnancy does not increase the risk of autism or attention-deficit/hyperactivity disorder, two new large studies suggest. Genetic or environmental influences, rather than prenatal exposure to the drugs, may have a greater influence on whether a child will develop these disorders. The studies are published online April 18 in JAMA. Clinically, the message is “quite reassuring for practitioners and for mothers needing to make a decision about antidepressant use during pregnancy,” says psychiatrist Simone Vigod, a coauthor of one of the studies. Past research has questioned the safety of expectant moms taking antidepressants (SN: 6/5/10, p. 22).
4-18-17 Zika mosquito is spreading worldwide but WHO wants to stop it
Zika mosquito is spreading worldwide but WHO wants to stop it
Inspired by efforts that have curbed malaria, the World Health Organization wants to control the Aedes mosquito in every one of the 140 countries it is found. Mosquitoes beware. The World Health Organization is preparing a global “vector control” plan to track the movements of disease-spreading organisms worldwide. “The idea is to prevent outbreaks of disease instead of simply reacting to new ones,” says Raman Velayudhan, head of vector control for neglected tropical diseases at the WHO. The plan particularly focusses on the Aedes mosquitoes that can carry the viruses that cause Zika, dengue, chikungunya and yellow fever. Aedes have massively expanded their range in recent years – before 1970, they were a threat in seven countries, but have now reached 140, says Velyudhan. Now the WHO wants to control their numbers. “Zika was a real wake-up call – we need to mobilise mosquito control measures wherever Aedes mosquitoes live,” says Velyudhan.
4-18-17 Fish 'pool' their experience to solve problems
Fish 'pool' their experience to solve problems
Fish pool their experience to solve problems collectively, according to new research. They might only have a little bit of information about their environment, but in a group, different animals might have separate but complementary information about a particular problem. Some may know where to find food but not how to access it. Others might know how to get at it but not where it is hidden, scientists at St Andrews University found. In a set of experiments, scientists at the university's school of biology set out to determine whether leadership - the pulling of the group by informed members - could allow groups of animals to pool their experience in order to solve problems collectively. Their findings, which could have implications for businesses and even bio-inspired swarm robotics, are published on the Nature Ecology & Evolution website.
4-17-17 Early dinosaur relative sported odd mix of bird, crocodile-like traits
Early dinosaur relative sported odd mix of bird, crocodile-like traits
Unusual museum specimen inspired search for more fossils. Unlike other known close dinosaur relatives, Teleocrater rhadinus walked on four feet instead of two and had an ankle bone like a crocodile’s. While researching fossils in a museum in 2007, Sterling Nesbitt noticed one partial skeleton that was hard to place. Though the reptile — at the time, unofficially called Teleocrater rhadinus — was thought to be a dinosaur relative, it was an oddball. At about 2 meters long, it was larger than other close relatives, walked on four feet instead of two, and had an unusually long neck and tail. Since the skeleton was missing some key bones, it was hard to know where the creature, found in Tanzania in 1933, fit within Archosauria, the group that includes crocodiles, birds and dinosaurs. Nesbitt, himself on the way to Tanzania for a dig, couldn’t shake thoughts of the strange fossil. “It would be nice if we found more,” the vertebrate paleontologist, now at Virginia Tech, remembers thinking. Now, a decade later, he and colleagues have done just that, discovering three additional partial skeletons of T. rhadinus — including bones missing from the original specimen. The more complete picture of T. rhadinus provides the first good glimpse of a pivotal moment of dino history.
4-14-17 Lazy fit animals: How some beasts get the gain without the pain
Lazy fit animals: How some beasts get the gain without the pain
Wish you could get fit without the effort? Make like a goose and just sit around and eat, says Richard Lovett. AS MORE than 40,000 runners prowl the start line of the London marathon this weekend, many of them will be wondering what they have got themselves into. Even without a heavy novelty costume, and no matter how well they have stuck to their training regime, running non-stop for 26.2 miles (42 kilometres) is going to hurt. Now consider the barnacle goose. Before setting off on a 3000-kilometre migration, it undertakes the training equivalent of sitting on the sofa guzzling fish and chips. What about the months of gradually building up fitness, followed by a steady taper before the big day? That’s not really the barnacle goose’s style. Instead, says Lewis Halsey, an environmental physiologist at the University of Roehampton, London, “they just basically sit on the water and eat a lot”. Scientists are only now beginning to investigate how this can be. Until recently, nobody had really asked whether exercise is as tightly connected to fitness in the rest of the animal kingdom as it is for us. In the past year or two, though, a handful of researchers have been inspired to do so by seemingly lazy creatures that manage feats of endurance that make marathons pale by comparison. The question is tied up in a broader assumption: that, because of the exercise they get finding food and escaping predators, wild animals live at the peak of physical fitness. Halsey, who recently wrote an article for the Journal of Animal Ecology with the provocative title “Do animals exercise to keep fit?”, points out that this may not necessarily be the case.
4-14-17 Psychedelic drug ayahuasca improves hard-to-treat depression
Psychedelic drug ayahuasca improves hard-to-treat depression
The first randomised trial of a shamanistic brew from South America has found it rapidly improves mood in people with depression that is resistant to antidepressants. It tastes foul and makes people vomit. But ayahuasca, a hallucinogenic concoction that has been drunk in South America for centuries in religious rituals, may help people with depression that is resistant to antidepressants. Tourists are increasingly trying ayahuasca during holidays to countries such as Brazil and Peru, where the psychedelic drug is legal. Now the world’s first randomised clinical trial of ayahuasca for treating depression has found that it can rapidly improve mood. The trial, which took place in Brazil, involved administering a single dose to 14 people with treatment-resistant depression, while 15 people with the same condition received a placebo drink. A week later, those given ayahuasca showed dramatic improvements, with their mood shifting from severe to mild on a standard scale of depression. “The main evidence is that the antidepressant effect of ayahuasca is superior to the placebo effect,” says Dráulio de Araújo of the Brain Institute at the Federal University of Rio Grande do Norte in Natal, who led the trial.
4-14-17 Start-up uses biometrics to tailor music for good night’s sleep
Start-up uses biometrics to tailor music for good night’s sleep
Trouble kipping? Boston-based Sync Project is collecting heart-rate data from music lovers to see if it can tweak tracks for better relaxation. A baby falling back to sleep at 2 am to a gentle lullaby may convince its parents that music can induce sleep, but new compositions designed to help listeners relax sound rather different to Rock-a-bye Baby. Boston-based start-up Sync Project uses biometrics to tailor music to your mood. Its Unwind app measures your heart beat via your smartphone’s accelerometer and uses these readings to tweak a relaxing ambient track by UK band Marconi Union. After listening, you take a brief survey. How relaxed do you feel? “Music can be used for everyday wellness as well as for clinical applications,” says Sync Project co-founder Ketki Karanam. Relaxation and sleep was an obvious place to start. “We decided to start by focusing on relaxation as we felt that was one area where people were using music to calm themselves down or relax,” she says. And people with sleep conditions are often looking for drug-free ways to sleep better. As well as the Unwind app, the company plans to collect biometric data from attendees at an overnight performance of neoclassical composer Max Richter’s eight-hour album Sleep – designed to help people nod off – at the Barbican in London next month. Concertgoers will be invited to wear activity-tracking OURA rings, which also monitor heart rate and body temperature. In addition, the volunteers will wear the rings while going to sleep at home, with and without the aid of Richter’s composition.
4-14-17 Shock-absorbing spear points kept early North Americans on the hunt
Shock-absorbing spear points kept early North Americans on the hunt
Chipping away parts of the weapon’s base prevented its tip from snapping off. Researchers studied how stone replicas of spear points (two at right) used by ancient Clovis people absorbed pressure. Results suggest Clovis points fluted at the base absorbed shock, preventing tip breakage while hunting. Ancient North Americans hunted with spear points crafted to absorb shock. Clovis people, who crossed a land bridge from Asia to North America around 13,500 years ago, fashioned stone weapons that slightly crumpled at the base rather than breaking at the tip when thrust into prey, say civil engineer Kaitlyn Thomas of Southern Methodist University in Dallas and colleagues. The Clovis crumple rested on a toolmaking technique called fluting, in which a thin groove was chipped off both sides of a stone point’s base, the researchers report in the May Journal of Archaeological Science.
4-14-17 Size matters to lizards, but numbers may not
Size matters to lizards, but numbers may not
Tests in Italian ruin or wall lizards suggests that the reptiles can assess dinner based on volume differences between two food ideas but not on the number of food items available. The quantitative abilities of lizards may have their limits. From horses to salamanders, lots of different species display some form of number sense, but the phenomenon hasn’t been investigated in reptiles. So a team of researchers in Italy set up two experiments for 27 ruin lizards (Podarcis sicula) collected from walls on the University of Ferrara’s campus. In the first test, the team served up two house fly larvae of varying sizes. Lizards consistently chose to scarf down bigger maggots. Then in the second experiment, the researchers gave lizards a choice between different numbers of larvae that were all the same size. The lizards didn’t show a preference. While the data suggest that the reptiles do discriminate between larger and smaller prey, they don't distinguish between higher and lower numbers of maggots in a meal, the scientists report April 12 in Biology Letters.
4-13-17 Our ability to think in a random way peaks at 25 then declines
Our ability to think in a random way peaks at 25 then declines
It’s harder than you think to make up a random sequence. Our ability to do so changes with age – and could give insight into cognitive decline. It’s surprisingly difficult to come up with a truly random sequence of numbers or items. Doing so requires cognitive skills such as memory and attention, as well as a sense of complexity. “Our brains are wired to find patterns even where there are none – for example, when looking at clouds or stars in the sky,” says Hector Zenil at the Karolinska Institute in Stockholm, Sweden, and the LABORES Research Lab in Paris, France. Zenil and his colleagues have now found that our ability to think up random sequences peaks when we reach 25 before declining with age. This mirrors the evolution and decline of our cognitive abilities, suggesting that monitoring this skill could give an insight into these changes over time. They asked more than 3400 people between the ages of 4 and 91 to complete an online assessment that included five tasks designed to measure their ability to generate random sequences. These included creating a hypothetical list of the results of flipping a coin 12 times and guessing which card would come next in a shuffled pack of cards. To measure how random people’s answers were, the researchers used a concept called “algorithmic randomness”. The idea is that if a sequence is truly random, it should be difficult to create an algorithm or computer program that can generate it. Statistics software provided an estimate of how complex this would be for each response.
4-13-17 Creative people physically see and process the world differently
Creative people physically see and process the world differently
Those who display a high degree of the openness personality trait may be more creative because of the way they process visual information. If you’re the kind of person who relishes adventure, you may literally see the world differently. People who are open to new experiences can take in more visual information than other people and combine it in unique ways. This may explain why they tend to be particularly creative. Openness to experience is one of the “big five” traits often used to describe personality. It is characterised by curiosity, creativity and an interest in exploring new things. Open people tend to do well at tasks that test our ability to come up with creative ideas, such as imagining new uses for everyday objects like bricks, mugs or table tennis balls. There’s some evidence that people with a greater degree of openness also have better visual awareness. For example, when focusing on letters moving on a screen, they are more likely to notice a grey square appearing elsewhere on the display. Now Anna Antinori at the University of Melbourne in Australia and her team are showing that people who score more highly when it comes to the openness trait “see” more possibilities. “They seem to have a more flexible gate for the visual information that breaks through into their consciousness,” Antinori says.
4-13-17 In sync: How to take control of your many body clocks
In sync: How to take control of your many body clocks
You have not one, but thousands or even millions of body clocks. Learn to control them, and you can tackle problems from jet lag to weight loss. GERDA POT’S grandmother was a stickler for timekeeping. “She always had breakfast at the same time, lunch and dinner at the same time, but even in between she had tea and coffee breaks every day at the same time,” says Pot. She also aged robustly, living independently well into her 90s. That got Pot wondering: was there something in the regularity of her grandmother’s habits that held the key to her rude health? A nutrition researcher at King’s College London, Pot was better placed than most to investigate – and she soon found she wasn’t the first to ask such questions. She had stumbled into the field of chrononutrition, and is now one of a growing number shedding light on the misunderstood role of time in human biology. We have known for a long time that messing with our body clocks can take a severe toll on our health. For decades, however, we thought that the body clock was one central timepiece housed in our brain. No longer. We now know our bodies contain thousands, if not millions, of disparate clocks that carefully orchestrate the functioning of our tissues and organs from the heart to the lungs to the liver. These clocks mean not only that there are benefits to eating regularly, as Pot and others are discovering, but that different parts of the body are tuned to work optimally at certain times of the day. When these clocks fall out of sync it can have serious consequences. Conversely, learn how to take advantage of these rhythms and we could be on a fast track to everything from slimmer waistlines to more effective treatments for cancer.
4-13-17 Fast CRISPR test easily detects Zika and antibiotic resistance
Fast CRISPR test easily detects Zika and antibiotic resistance
A method that uses the gene-editing tool CRISPR to recognise certain DNA sequences could make it quick and cheap to test for pathogens or genetic variants. CRISPR has another trick up its sleeve. The system that sparked a revolution in gene editing can also be used in fast and cheap tests for pathogens. A tool based on CRISPR has been shown to detect the Zika virus in blood, urine and saliva. It was developed by researchers at the Broad Institute in Cambridge, Massachusetts, who call it SHERLOCK – for Specific High Sensitivity Enzymatic Reporter Unlocking. CRISPR was discovered in E. coli, which uses it to recognise the genetic material of viruses and destroy it. So far, researchers have mostly exploited CRISPR as a gene-editing tool, but it may also prove useful for medical testing. “Once we realised how the enzyme works, we saw that it could have unlimited applications in diagnostics,” says team member Omar Abudayyeh. The SHERLOCK tool works by making RNA copies of DNA. It then uses CRISPR to search for specific genetic sequences. Once found, an enzyme causes fluorescence, signalling the detection of the desired target.
4-12-17 Vaccinating pregnant women protects newborns from whooping cough
Vaccinating pregnant women protects newborns from whooping cough
A Tdap vaccine during pregnancy led to fewer newborns getting whooping cough in the two months after birth, a large study found. When I was pregnant, my pronoun shifted automatically. My “I” turned into “we,” as in, “What are we going to eat for dinner?” and, “Should we sit in that hot tub?” I thought about that shift to the majestic plural as we got our Tdap shot in our third trimester. The Tdap vaccine protects against tetanus, diphtheria and pertussis, or whooping cough. Doctors recommend that women receive a dose with each pregnancy because the diseases can be particularly dangerous for young babies. But good, hard evidence for the benefits of vaccinating women while pregnant instead of shortly after giving birth has been lacking. A new study of nearly 150,000 newborns fills that gap for whooping cough.
4-12-17 Rules restricting artificial trans fats are good for heart health
Rules restricting artificial trans fats are good for heart health
In wake of policy change, heart attack and stroke incidence dropped, study shows. Starting in 2007, areas of New York restricted the use of partially hydrogenated oils in eateries, eliminating artificial trans fats from foods like these french fries. As a result, residents experienced fewer heart attacks and strokes, a new study suggests. Taking artificial trans fats off the menu reduces hospitalizations for heart attack and stroke, suggests a study that examined what happened after several areas in New York restricted the fats’ use. The findings portend larger scale public health benefits after a nationwide ban on artificial trans fats begins in the United States in 2018. Hospital admission rates for heart attacks declined 7.8 percent more in New York counties that restricted trans fats than in those counties that had not, researchers report online April 12 in JAMA Cardiology.
4-12-17 Gene knockouts in people provide drug safety, effectiveness clues
Gene knockouts in people provide drug safety, effectiveness clues
Study in Pakistanis provides data on function-destroying mutations. Geneticists examined DNA from more than 10,000 people in Pakistan looking for people in whom both copies of certain genes were nonfunctional. High rates of marriage between closely related people there make it more likely that people will inherit two nonfunctional gene copies. Some Pakistani people are real knockouts, a new DNA study finds. Knockouts in this sense doesn’t refer to boxing or a stunning appearance, but to natural mutations that inactivate, or “knock out” certain genes. The study suggests that human knockouts could prove valuable evidence for understanding how genes work and for developing drugs. Among 10,503 adults participating in a heart disease study in Pakistan, 1,843 people have at least one gene of which both copies have been knocked out, researchers report online April 12 in Nature. Researchers also drew blood from many of the participants and used medical records to study more than 200 traits, such as heart rate, blood pressure and blood levels of sugar, cholesterol, hormones or other substances. Studying how the knockout mutations affect those traits and health could point to genes that are potentially safe and effective targets for new drugs.
4-12-17 Cells’ stunning complexity on display in a new online portal
Cells’ stunning complexity on display in a new online portal
The Allen Cell Explorer could reveal rules for building cells. Although stem cells are all genetically identical, they can adopt a variety of shapes. Computers don’t have eyes, but they could revolutionize the way scientists visualize cells. Researchers at the Allen Institute for Cell Science in Seattle have devised 3-D representations of cells, compiled by computers learning where thousands of real cells tuck their component parts. Most drawings of cells in textbooks come from human interpretations gleaned by looking at just a few dead cells at a time. The new Allen Cell Explorer, which premiered online April 5, presents 3-D images of genetically identical stem cells grown in lab dishes (composite, above), revealing a huge variety of structural differences.
4-12-17 Early dinosaur relative walked like a croc
Early dinosaur relative walked like a croc
One of the earliest relatives of dinosaurs had some features we associate today with crocodiles and alligators, a study suggests. Many palaeontologists have wondered what the earliest dinosaur relatives looked like, as the fossil record in this time period is sparse. Some assumed they walked on two legs, looking a bit like miniature dinosaurs. But the newly described creature walked on four legs like a croc, the journal Nature reports. The 2-3m (7-10ft) carnivorous animal, unearthed in southern Tanzania, lived some 245 million years ago during the Triassic Period. It pre-dated the earliest dinosaurs.
4-11-17 Entire nervous system of an animal recorded for the first time
Entire nervous system of an animal recorded for the first time
Every neuron in a hydra has been seen firing. The breakthrough helps us understand basic behaviour and could lead to us unlocking the secrets of our own brains. The firing of every neuron in an animal’s body has been recorded, live. The breakthrough in imaging the nervous system of a hydra – a tiny, transparent creature related to jellyfish – as it twitches and moves has provided insights into how such simple animals control their behaviour. Similar techniques might one day help us get a deeper understanding of how our own brains work. “This could be important not just for the human brain but for neuroscience in general,” says Rafael Yuste at Columbia University in New York City. Instead of a brain, hydra have the most basic nervous system in nature, a nerve net in which neurons spread throughout its body. Even so, researchers still know almost nothing about how the hydra’s few thousand neurons interact to create behaviour. To find out, Yuste and colleague Christophe Dupre genetically modified hydra so that their neurons glowed in the presence of calcium. Since calcium ions rise in concentration when neurons are active and fire a signal, Yuste and Dupre were able to relate behaviour to activity in glowing circuits of neurons. For example, a circuit that seems to be involved in digestion in the hydra’s stomach-like cavity became active whenever the animal opened its mouth to feed. This circuit may be an ancestor of our gut nervous system, the pair suggest.
4-11-17 Gene editing opens doors to seedless fruit with no need for bees
Gene editing opens doors to seedless fruit with no need for bees
Gene-edited seedless tomatoes don’t need pollinating to produce fruit – which could come in useful at a time when bees are on the decline. By Alice Klein: Don’t like the seeds in tomatoes? You might be pleased to know that seedless ones have been created by gene editing. The technique will make it possible to make a much wider range of seedless fruits than is currently available – and also means farmers might not have to rely on declining bee populations. Whether we ever see such fruits on supermarket shelves, however, may depend on how regulators decide to treat gene-edited crops. Several types of seedless fruits, from bananas to cucumbers to grapes, are already widely available, but many have come about by luck rather than design. Seedless bananas are the result of accidental crosses between subspecies, for instance, while other seedless fruits stem from spontaneous mutations. There are a few seedless varieties of tomato, but they have taken breeders many years to create. Now Keishi Osakabe at Tokushima University in Japan and his colleagues have used the CRISPR gene-editing technique to deliberately introduce a mutation that makes tomatoes seedless. The mutation increases levels of a hormone called auxin, which stimulates fruits to develop even though no seeds have begun to form.
4-11-17 Research reveals how to take better breaks
Research reveals how to take better breaks
Put down the smartphone and make time to daydream. Until recently, when I needed a break I'd grab my phone. Whether I was bored, mentally fatigued, or just wanting a pick-me-up, I felt relief checking the news, Facebook, or Instagram. However, recent research suggests there are good ways and not-so-good ways to spend our break time. While some breaks can leave us refreshed and re-energized, others tend to leave us depleted and drained. In their book The Distracted Mind: Ancient Brains in a High-Tech World Dr. Gazzaley, a neuroscientist, and Dr. Rosen, a psychologist, explain that good breaks can reduce mental fatigue, boost brain function, and keep us on-task for longer periods. But Gazzaley and Rosen forewarn that taking the wrong sort of breaks might make us more susceptible to boredom and may actually backfire by making us want to take breaks more often. In other words, repeatedly checking our phones when we get a tad bored can train us to check more often throughout the day. The rapid rewards we get from skimming our newsfeeds alleviate boredom for a few moments, but they also teach our brains to seek out blips of joy the next time we feel a twinge of fatigue, Gazzaley and Rosen explain, "[…] the next time we are bored, our past experiences, having gained reinforcement from our smartphone, will drive us to self-interrupt…" So by reaching for our phones when we want a break, we may be training ourselves to do it again and again. In order to resist the onset of boredom and self-interruption at work, Gazzaley and Rosen suggest we avoid our smartphones and instead take breaks that restore the part of the brain we use to keep focused on our goals.
4-11-17 Poo sediments record Antarctic 'penguin Pompeii'
Poo sediments record Antarctic 'penguin Pompeii'
The perilous history of a penguin colony on a small Antarctic island has been recorded in their excrement. For thousands of years, the birds have nested on the Ardley outcrop where their poop, or guano, would collect at the bottom of a lake. But when scientists drilled into these sediments, they got quite a surprise. Interspersed with the layers of penguin waste were thick sections of volcanic ash, indicating the Ardley birds were frequently decimated by eruptions. "What causes the biggest declines in the penguins is the volcanic activity on nearby Deception Island," explained Stephen Roberts from the British Antarctic Survey (BAS). "Eruptions have gone off at regular intervals over the last 7,000 years. We found there were five phases when the penguin population grew quite significantly, and for three of these the population crashed. This was due to the volcano going off," he told BBC News.
4-10-17 Injecting virus into brain may relieve Parkinson’s symptoms
Injecting virus into brain may relieve Parkinson’s symptoms
A virus has been used to reprogram cells in the brains of mice so that they produce dopamine – the brain chemical missing in people who have Parkinson’s disease. Using a virus to reprogram cells in the brain could be a radical way to treat Parkinson’s disease. People with Parkinson’s have difficulty controlling their movements due to the death of neurons that make dopamine, a brain signalling chemical. Transplants of fetal cells have shown promise for replacing these dead neurons in people with the disease, and a trial is currently under way. But the transplant tissue comes from aborted pregnancies, meaning it is in short supply, and some people may find this ethically difficult. Recipients of these cells have to take immunosuppressant drugs too. Ernest Arenas, at the Karolinska Institute in Stockholm, Sweden, and his team have found a new way to replace lost dopamine-making neurons. They injected a virus into the brains of mice whose dopamine neurons had been destroyed. This virus had been engineered to carry four genes for reprogramming astrocytes – the brain’s support cells – into dopamine neurons. Five weeks later, the team saw improvements in how the mice moved. “They walked better and their gait showed less asymmetry than controls,” says Arenas. This is the first study to show that reprogramming cells in the living brain can lead to such improvements, he says. The team found such a strong correlation between dreaming and fewer low-frequency waves in the “hot zone” that they could successfully predict whether a person was dreaming 91 per cent of the time.
4-10-17 We dream loads more than we thought – and forget most of it
We dream loads more than we thought – and forget most of it
The brain area that controls dreaming has been discovered. Studying its activity has revealed that even in non-REM sleep, we dream 71 per cent of the time. You dream more than you know. A new way to detect dreaming has confirmed that it doesn’t only occur during rapid eye movement (REM) sleep, and has shown why we often don’t remember our dreams. “There is much more dreaming going on than we remember,” says Tore Nielsen at the University of Montreal, Canada. “It’s hours and hours of mental experiences and we remember a few minutes.” During sleep, low-frequency brainwaves are detectable across the brain. Now Francesca Siclari at the University of Wisconsin-Madison and her colleagues have discovered that a decrease in these waves in an area at the back of the brain is a sign that someone is dreaming. “This zone was a little bit more awake, showing high-frequency brainwaves more common during wakefulness,” says Siclari. This one region seems to be all that’s necessary for dreaming, she says.
4-10-17 Life could exist up to 10 kilometres beneath the sea floor
Life could exist up to 10 kilometres beneath the sea floor
Samples from a mud volcano contain biological signatures that suggest microbes lived in the material when it was rock several kilometres beneath the ocean floor. LIFE might eke out an existence far deeper inside Earth than we imagined. Samples from a mud volcano contain biological signatures that suggest microbes lived in the material when it was several kilometres beneath the ocean floor. “We might have a very big biosphere below our feet that’s very hard to get to,” says Oliver Plümper of Utrecht University in the Netherlands. Other researchers agree life could exist at such depths, but say the case is not yet proven. “They don’t have conclusive evidence,” says Rocco Mancinelli, an astrobiologist at NASA’s Ames Research Center, who studies life in extreme environments. Plümper’s team studied 46 samples drilled from the South Chamorro mud volcano, near the deepest part of the ocean, the Mariana trench. Here, one tectonic plate slides under another. The heat and stress causes some of the material on the subducting plate to become a buoyant mineral called serpentinite that rises and erupts out of mud volcanoes. Examining the serpentinite in their samples, the team found chemicals usually produced by life, including amino acids and hydrocarbons. Given that some microbes can withstand temperatures as high as 122°C and pressures about 3000 times higher than at Earth’s surface, Plümper calculates that life could survive up to 10 kilometres beneath the seabed.
4-10-17 The most important fossil you've never heard of
The most important fossil you've never heard of
t's not a household name, but an ancient creature found in the Scottish borders fills a crucial period in the evolutionary record. It sheds light on how four-limbed creatures became established on land. An ancient animal found in rocks from the Scottish borders is thought to be the earliest known example of an animal with a backbone to live on land. The fossilised remains of this highly significant creature, called Tiny, shed light on a key period in our evolutionary history. Tiny has four limbs, a pair of lungs and up to five fingers (the fossil evidence is unclear exactly how many). "It was one small step for Tiny, one giant leap for vertebrates," said palaeontologist Dr Nick Fraser in an interview on the BBC Radio 4's Life Scientific. "Without Tiny, there would be no birds, no dinosaurs, no crocodiles, no mammals no lizards and obviously we wouldn't be around."
4-10-17 People on ecstasy feel loved-up because MDMA boosts trust
People on ecstasy feel loved-up because MDMA boosts trust
When men play the trust game Prisoner's Dilemma after taking ecstasy, they are twice as likely to cooperate. This may mean the drug could assist therapy for PTSD. ECSTASY makes you feel like everyone’s your friend. Now an experiment in which people played a trust game after taking the drug is helping to explain why. Also called MDMA, ecstasy is known to trigger the release of the brain chemical serotonin, as well as mimicking its actions in the brain. Investigating how this affects us could help us understand how we govern our social actions, and how this process goes awry in depression and schizophrenia, says Anthony Gabay at King’s College London. In their latest study, Gabay and his team gave 20 men MDMA and asked them to play a game called Prisoner’s Dilemma on a computer while lying in a brain scanner. The points earned in the game depend on whether you cooperate with or betray your opponent, and on what they choose to do. The game gets more complex if played over a number of rounds, because while you earn the most points on a single round by betraying your opponent, you earn more over time if both people cooperate. The men played 15 rounds of the game with the same opponent, allowing relationships to build – although unbeknown to them, they were playing against a computer. When they were given MDMA, they became euphoric and talkative. “Some of them wanted to hug me,” says Gabay. In this state, they cooperated twice as often as when they had played the game after being given a placebo – if their opponent was usually trustworthy.
4-10-17 Scientists seek early signs of autism
Scientists seek early signs of autism
Biomarkers could aid diagnosis and lead to strategies for treatment. High-risk babies — younger siblings of a child with autism — who will be diagnosed with autism themselves had more rapid growth in parts of their brains than low-risk babies who will not later get an autism diagnosis. Soon after systems biologist Juergen Hahn published a paper describing a way to predict whether a child has autism from a blood sample, the notes from parents began arriving. “I have a bunch of parents writing me now who want to test their kids,” says Hahn, of Rensselaer Polytechnic Institute in Troy, N.Y. “I can’t do that.” That’s because despite their promise, his group’s results, reported March 16 in PLOS Computational Biology, are preliminary — nowhere close to a debut in a clinical setting. The test will need to be confirmed and repeated in different children before it can be used to help diagnose autism. Still, the work of Hahn and colleagues, along with other recent papers, illustrates how the hunt for a concrete biological signature of autism, a biomarker, is gaining speed. Currently, pediatricians, child psychologists and therapists rely on behavioral observations and questionnaires, measures with limitations. Barring genetic tests for a handful of rare mutations, there are no blood draws, brain scans or other biological tests that can reveal whether a child has — or will get — autism.
4-10-17 Bedbugs bugged prehistoric humans, too
Bedbugs bugged prehistoric humans, too
cientists found ancient remains of three different bedbug species in an Oregon cave, including this 5,100-year-old female Cimex antennatus. The oldest known specimens of bedbug relatives have been unearthed in an Oregon cave system where ancient humans once lived. The partial fossils from three different species in the bedbug family date back 5,000 to 11,000 years, predating a previous find from 3,500 years ago, researchers report April 4 in the Journal of Medical Entomology. “The bedbugs that we know in modern times originated as bat parasites, and it’s believed that they became human parasites when humans lived in caves with bats,” says study coauthor Martin Adams of Paleoinsect Research in Portland, Ore. When humans moved elsewhere, bedbugs came along for the ride. These three species (Cimix antennatus, Cimex latipennis and Cimex pilosellus) probably coexisted with humans in Oregon’s Paisley Five Mile Point Caves, and probably snacked on people at least occasionally, Adams says. Even though all three species are still around today, they still feast mostly on bats. Archaeologists think that ancient humans lived in the Paisley Caves only seasonally, which could explain why these particular species of bedbugs didn’t switch to a human-centric diet.
4-9-17 The enormous economic costs of America's obesity epidemic
The enormous economic costs of America's obesity epidemic
America’s obesity epidemic is fueling a boom in expensive weight-loss surgery, extra-wide hospital beds, and supersize grave plots. In an operating room at Baptist Memphis Hospital, surgeon George Woodman stood over a sedated patient, preparing to insert a 5-inch needle into her huge abdomen, draped with yards of blue surgical cloth. The 30-year-old patient weighed 330 pounds, with a body mass index of 46 — so heavy she's considered "morbidly" obese. Woodman made five small incisions and slowly inserted the instruments he would use to remove most of her stomach. As he and his team worked, the patient's organs — stomach, spleen, pancreas, liver, pulsing heart — could be seen on a video monitor. Two gaping hernias became visible, holes torn in the abdominal sac that holds the body's major organs. "The belly wall is not designed to hold this much weight," Woodman observed. He pointed out the many tiny blood vessels in the stomach lining. "The stomach has a lot of blood supply. That's why it's so good at absorbing terrible foods," he said. By the operation's end, most of the patient's stomach was trimmed away, leaving a much smaller "gastric sleeve" that would allow her to feel full after eating only small amounts of food. Removing a portion of the stomach also suppresses the hormones that stimulate hunger. The operation (known as a laparoscopic sleeve gastrectomy) is now the most common type of weight-loss surgery performed in the U.S. Woodman has conducted 6,000 bariatric surgeries, and did three more that morning. Memphis is the heaviest metropolitan city in the country, with an adult obesity rate of about 36 percent — approaching the rate of more than 40 percent that researchers say we'll reach by 2030, if current trends continue. "There is an unlimited number of patients," he said.
4-7-17 Genetic risk of getting second cancer tallied for pediatric survivors
Genetic risk of getting second cancer tallied for pediatric survivors
Faulty genes, not just treatment side effects, to blame for double whammy. Some pediatric cancer survivors carry genetic mutations that increase the risk of a later, second cancer. A second cancer later in life is common for childhood cancer survivors, and scientists now have a sense of the role genes play when this happens. A project that mined the genetic data of a group of survivors finds that 11.5 percent carry mutations that increase the risk of a subsequent cancer. “We’ve always known that among survivors, a certain population will experience adverse outcomes directly related to therapy,” says epidemiologist and team member Leslie Robison of St. Jude Children’s Research Hospital in Memphis. The project sought “to find out what contribution genetics may play.” The team presented their work at the American Association of Cancer Research meeting April 3.
4-7-17 Oldest tooth filling was made by an Ice Age dentist in Italy
Oldest tooth filling was made by an Ice Age dentist in Italy
A pair of 13,000-year-old front teeth show that ancient dentists used bitumen mixed in with plants and hairs to create rudimentary fillings. Scared of the dentist? Be glad you don’t live in the Ice Age. A pair of 13,000-year-old front teeth found in Italy contain the earliest known use of fillings – made out of bitumen. The teeth, two upper central incisors belonging to one person, were discovered at the Riparo Fredian site near Lucca in northern Italy. Each tooth has a large hole in the incisor’s surface that extends down into the pulp chamber deep in the tooth. “It is quite unusual, not something you see in normal teeth,” says Stephano Benazzi, an archaeologist at the University of Bologna. Benazzi and his team used a variety of microscopic techniques to get a close look at the inside of the holes, and found a series of tiny horizontal marks on the walls that suggest they were cavities that had been drilled out and enlarged, likely by tiny stone tools. The markings were similar to those Benazzi and his colleagues found in teeth from another site in Italy, dated to 14,000 year ago, that they determined were the first known example of dentistry in humans. But these new teeth also have a new dental innovation. The holes contain traces of bitumen, with plant fibres and hairs embedded in it, which Benazzi thinks are evidence of prehistoric fillings. While the purpose of the plants and hairs is unknown, it appears that they were added to the cavity at the same time as the drilling, so are not simply the remains of food eaten later.
4-7-17 Stone Age hunter-gatherers tackled their cavities with a sharp tool and tar
Stone Age hunter-gatherers tackled their cavities with a sharp tool and tar
Tooth find adds to evidence that some form of dentistry has existed for at least 14,000 years. Seen from above in computer reconstructions, cavities in two human teeth dating to around 13,000 years ago contain signs of an ancient treatment for tooth decay. Marks on the inner walls of each cavity were made by a pointed stone tool used to remove infected tissue, researchers propose. Stone Age dentists didn’t drill and fill cavities. They scraped and coated them. Two teeth from a person who lived in what’s now northern Italy between 13,000 and 12,740 years ago bear signs of someone having scoured and removed infected soft, inner tissue. The treated area was then covered with bitumen, a sticky, tarlike substance Stone Age folks used to attach stone tools to handles (SN Online: 12/12/08), says a team led by biological anthropologists Gregorio Oxilia and Stefano Benazzi, both of the University of Bologna in Italy. The find indicates that techniques for removing infected parts of teeth developed thousands of years before carbohydrate-rich farming diets made tooth decay more common, the researchers report online March 27 in the American Journal of Physical Anthropology. Farmers may have used stone tools to drill dental cavities as early as 9,000 years ago (SN: 4/8/06, p. 213). Oxilia and Benazzi’s team reported in 2015 that a pointed stone tool had apparently been used to remove decayed tissue from a tooth that belonged to a man buried in northern Italy around 14,000 years ago.
4-7-17 Sugar, the new food villain
Sugar, the new food villain
Sugar is everywhere. Eighty percent of supermarket foods contain it—and purportedly “savory” foods often contain more sugar than sweet treats like ice cream. Whole-wheat bread can have a teaspoon of sugar per slice; Heinz tomato ketchup contains 22.8 percent sugar, twice as much as Coca-Cola. As we swamp our bodies with sugar, we only become more addicted. A 2016 study in Nature Neuroscience suggested that sugar hijacks the brain by triggering its reward system, pushing the body to ask for more and more. Sugar might even be more addictive than recreational drugs, says cardiovascular research scientist James DiNicolantonio. “When you look at animal studies comparing sugar to cocaine, even when you get the rats hooked on intravenous cocaine, once you introduce sugar, almost all of them switch to the sugar.”
- Why is sugar in the spotlight?
- How much sugar do we consume?
- What did Big Sugar do next?
- Why is sugar so bad for us?
- Do all nutritionists agree?
- What can be done?
- America’s favorite drug
4-7-17 Marathons tax the kidneys
Marathons tax the kidneys
Running a marathon may be about as traumatic for the kidneys as heart surgery, reports CNN.com. To assess how running 26.2 miles affects kidney function, researchers from Yale University collected blood and urine samples from a group of people just before they ran the Hartford Marathon, and then immediately afterward. They found that after the race 82 percent of the runners had signs of acute kidney injury—likely due to dehydration—as well as reduced blood flow to vital organs and a rise in core body temperature. “Almost everybody had a significant increase in the novel markers of injury, inflammation, and repair,” says study leader Chirag Parikh. The researchers found these effects were only temporary, and reversed within 48 hours. But they warned that the long-term impact of running marathons remains unknown, and said their findings emphasize that runners should stay well hydrated and avoid medications that are toxic to the kidneys.
4-7-17 Aging-reversal treatment
Scientists studying age-related disease may be one step closer to a therapy that could help reverse the ravages of time. Researchers in the Netherlands have been investigating senescent cells, “zombie” cells that have stopped dividing and that can contribute to illnesses such as heart disease, arthritis, and diabetes. For a new study, the team designed a molecule to selectively kill these cells in mutant mice that age rapidly, without harming healthy cells. The therapy restored the rodents’ kidney function, stimulated the growth of their fur, and improved their stamina. The researchers are now studying whether the mice also live longer. They believe the procedure could potentially be used to treat age-related disorders in humans and even to kill cancer cells, which share certain features with senescent cells. “It’s definitely a landmark advance,” University of Montreal biologist Francis Rodier, who wasn’t involved in the study, tells Science. “This is the first time that somebody has shown that you can get rid of senescent cells without having any obvious side effects.”
4-7-17 Tipping the scales
Tipping the scales
America’s obesity epidemic is fueling a boom in expensive weight-loss surgery, extra-wide hospital beds, and supersize grave plots, said journalist Beth Baker. The costs of the crisis are overwhelming our society.
4-7-17 Rules of memory 'beautifully' rewritten
Rules of memory 'beautifully' rewritten
What really happens when we make and store memories has been unravelled in a discovery that surprised even the scientists who made it. The US and Japanese team found that the brain "doubles up" by simultaneously making two memories of events. One is for the here-and-now and the other for a lifetime, they found. It had been thought that all memories start as a short-term memory and are then slowly converted into a long-term one. Experts said the findings were surprising, but also beautiful and convincing.
4-7-17 Most cancers caused by chance mutations
Most cancers caused by chance mutations
Scientists are always telling us what we can do to lower cancer risk: Exercise more, stay out of the sun, eat more of this and less of that. But new research suggests that two-thirds of cancer-causing genetic mutations are the result of random and unavoidable DNA errors—“bad luck,” as the authors put it. Mistakes occur every time a cell divides and copies its DNA to produce two new cells. Most of those mutations don’t cause any harm, reports NBCNews.com, but a small number affect so-called cancer driver genes. After analyzing genome sequencing and epidemiologic data from 32 cancer types in 69 countries, researchers at Johns Hopkins University found that 29 percent of cancer-causing mutations are the result of environmental factors, such as smoking and sun exposure; 5 percent are caused by inherited genetic mutations; and 66 percent are completely random. They note that arbitrary mutations are more common in cancers involving tissues with higher rates of cellular “turnover,” such as the colon. Critics of the study contend that cancer is a complex disease whose causes cannot be separated and simplified, and that people shouldn’t be discouraged from quitting smoking and taking other steps that reduce their cancer risk. But the authors say their findings offer comfort and reassurance to the millions of people who have been diagnosed with cancer despite living a healthy lifestyle. “It’s not your fault,” says co-author Bert Vogelstein.
4-6-17 Gluten allergy in coeliac disease may be provoked by virus
Gluten allergy in coeliac disease may be provoked by virus
Some people seem to get coeliac disease after having an infection. Now experiments in mice suggest a common virus might bring on the autoimmune condition. Infection with a common, symptomless virus could be one of the first steps towards developing coeliac disease, a painful autoimmune condition that damages the gut. Coeliac disease involves the immune system treating gluten as an antigen and attacking it and has generally been thought to be a genetic disease. However, there is some evidence that the onset of the condition may be linked to people experiencing viral infections. These may include infection by adenoviruses, which cause colds, rotaviruses, which can cause diarrhoea, and the hepatitis C virus. Now there is experimental evidence that some viruses may indeed prompt the onset of coeliac disease. Bana Jabri at the University of Chicago, Illinois, and her team have found that exposing mice to a common reovirus called T1L breaks their tolerance of gluten. When the team fed small groups of mice gliadin – a component of gluten – they found that mice produced two to three times as many antibodies against the compound over the next two days if they were also infected with reovirus. “The reovirus changes the way the immune system sees gluten,” says Jabri. Normally, the body’s immune system learns to tolerate the wide range of substances in our food, including gluten – a protein found in wheat, rye and barley. But the team’s findings suggest that infection with a reovirus interferes with this, leading the body to mistakenly attack gluten. “Our experiments are the first to demonstrate that a virus can induce loss of tolerance to dietary antigens,” says Jabri.
4-6-17 Mutation in clock gene explains why some night owls stay up late
Mutation in clock gene explains why some night owls stay up late
People with delayed sleep phase disorder go to sleep several hours later and hate getting up early. A variant of a circadian clock gene could be to blame. A gene variant may explain why some people prefer to stay up late and hate early mornings. The variant is a mutated form of the CRY1 gene, known to play a role in the circadian clock. Michael Young, at The Rockerfeller University, New York, and his team discovered the mutation in a person diagnosed with delayed sleep phase disorder – a condition that describes many so-called “night-owls”. The team found that five of this person’s relatives also had this mutation, all of whom had a history of sleep problems. They then studied six families in Turkey whose members included 39 carriers of the CRY1 variant. The sleep periods of those with the mutation was shifted by 2 to 4 hours, and some had broken, irregular sleep patterns. The mutation seems to slow the body’s internal biological clock, causing people to have a longer circadian cycle and making them stay awake later. The team have calculated that the variant may be present in as many as one in 75 people in some populations, such as Europeans of non-Finnish descent. But those who have a longer circadian cycle need not despair. Young says many people with delayed sleep phase disorder are able to control their sleep cycles by sticking to strict schedules. “It’s a bit like cigarette smoking in that there are things we can do to help the problem before turning to drugs,” he says.
4-6-17 Common virus may be celiac disease culprit
Common virus may be celiac disease culprit
Viral interaction with gluten may send wrong signal to immune system, mouse study finds. A reovirus may jump-start celiac disease by turning the immune system against gluten, a new study in mice suggests. A common and usually harmless virus may trigger celiac disease. Infection with the suspected culprit, a reovirus, could cause the immune system to react to gluten as if it was a dangerous pathogen instead of a harmless food protein, an international team of researchers reports April 7 in Science. In a study in mice, the researchers found that the reovirus, T1L, tricks the immune system into mounting an attack against innocent food molecules. The virus first blocks the immune system’s regulatory response that usually gives non-native substances, like food proteins, the OK, Terence Dermody, a virologist at the University of Pittsburgh, and colleagues found. Then the virus prompts a harmful inflammatory response.
4-6-17 Giant viruses may just be small viruses that stole hosts’ genes
Giant viruses may just be small viruses that stole hosts’ genes
Genome sequences found in a waste-water plant seem to question the possibility that giant viruses are a whole new domain of life – but not everyone is convinced. Mysterious microbes that some consider a whole new domain of life might in fact be just normal viruses that pilfer genes from their host organisms. Unlike normal viruses, which are tiny, giant viruses have hundreds of genes. This is one of the exotic features that has perplexed microbiologists, leading them to consider a new classification of life. But a study now argues that these microbial giants are just small viruses that grew large by stealing genes from their hosts – so not that special after all. The conclusion is, however, hotly contested by scientists who identified the first recognised giant virus in 2003. This first example, mimivirus, found in a water tower in Bradford, UK, has 1018 genes, compared with nine in a virus such as HIV. Since then, many more have been found, some of which are almost as large as bacterial cells, and some that even have other viruses that infect them. More bizarrely, 50 to 90 per cent of the genes in giant viruses are not found anywhere else, and many are not even shared with other giant viruses.
4-6-17 Squid and octopus can edit and direct their own brain genes
Squid and octopus can edit and direct their own brain genes
These animals do not obey the commands of their DNA to the letter, instead interfering with the code and possibly leading to a special kind of evolution. Octopuses and squid have confirmed their reputation as Earth-bound “aliens” with the discovery that they can edit their own genetic instructions. Unlike other animals, cephalopods – the family that includes octopuses, squid and cuttlefish – do not obey the commands of their DNA to the letter. Instead, they sometimes interfere with the code as it is being carried by a molecular “messenger”. This has the effect of diversifying the proteins their cells can produce, leading to some interesting variations. The system may have produced a special kind of evolution based on RNA editing rather than DNA mutations and could be responsible for the complex behaviour and high intelligence seen in cephalopods, some scientists believe. RNA, a close cousin of DNA, is used to transfer software-like instructions from the genes to protein-making machinery in cells. Scientists discovered that more than 60 per cent of RNA transcripts in the squid brain are re-coded by editing. In other animals, ranging from fruit flies to humans, such re-coding events only occur a fraction of 1 per cent of the time. Similar high levels of RNA editing were identified in three other “smart” cephalopod species, two octopuses and one cuttlefish.
4-6-17 Cephalopods may have traded evolution gains for extra smarts
Cephalopods may have traded evolution gains for extra smarts
Unusual level of RNA editing seen, especially in creatures’ brains. RNA editing may have made cuttlefish and related cephalopods intelligent, but has slowed their evolution, new research suggests. Octopus, squid and cuttlefish don’t always follow the rules laid out in their DNA. Straying from prescribed genetic instructions may have increased the cephalopods’ thinking prowess, but comes at a cost, a new study suggests. Once genes have been copied from DNA into RNA, these cephalopods heavily edit the genes’ protein-making directions, researchers report April 6 in Cell. The study involved a squid species, two octopus species and a cuttlefish species, all coleoids, or shell-less cephalopods. Each contained between 80,000 and 130,000 RNA sites that had been edited. This high level of editing contrasts with only 1,150 edited sites in RNA from a nautilus and 933 in a mollusk.
4-5-17 The scientific reason you should talk to yourself
The scientific reason you should talk to yourself
That critical voice in your head. Always telling you how you're screwing up. Always putting the worst-case-scenario front and center. We all have it. (I call it "Lefty.") You're hearing a lot these days about how to turn down the volume on your critical inner monologue. (Um, sometimes from me, actually.) But let's try looking at it a little differently for a sec, shall we? What if you don't need fewer voices in your head — what if you need more of them? There's plenty of evidence that the right voices in your head can make you smarter, more confident, and more resilient. When you want to muster your energy or self-control for a challenge, you might say, "I can do it." And if that's what you're saying, well, I'd reply, "No, actually. No, you can't." Because here's what's crazy: Research shows talking to yourself using the word "you" is more powerful than using the word "I": Altogether, the current research showed that second-person self-talk strengthens both actual behavior performance and prospective behavioral intentions more than first-person self-talk. So a voice in your head that seems to be another person actually has more power to get your keister moving than "you" talking to "you." So pull a few extra chairs up to your mental table. We're putting a Brain Trust together — but they're all in your one brain. Here are the three voices you need chattering away in your head…
- The voice that makes you resilient
- The voice that makes you smarter
- The voice that makes you feel better about yourself
4-5-17 Internal conflict: How we can make friends with harmful bacteria
Internal conflict: How we can make friends with harmful bacteria
When we wipe out vicious bacteria with antibiotics, beneficial bugs get killed in the friendly fire, fuelling obesity and diabetes. But there is another way. YOU are home to 10,000 species of bacteria. The vast majority, more than 99 per cent, cause you no harm. Indeed, many actually help by providing you with nutrients, tuning your immune system, balancing your metabolism and warding off mood disorders. You depend on these bugs. Yet as anyone who’s had an upset stomach after taking antibiotics can attest, when we target the dangerous minority of disease-causing species, we often wind up killing off the good ones too. Now, after generations of doctors prescribing antibiotics for every sniffle, we know that the collateral damage goes well beyond the occasional tummy ache. Indiscriminately wiping out bacteria may be contributing to rising levels of asthma, allergies, obesity and many more conditions. These effects, together with the growing threat from antibiotic resistance, have some researchers advocating a sea change in the battle against the bugs: after 70 years of fighting to wipe them out, it may be time for a truce. If we can disarm harmful bacteria without killing them, we may be able to reduce antibiotic resistance, take the strain off these overworked drugs and leave our helpful inhabitants be. Doing so may even mean resurrecting some forgotten strategies from the past. If the 20th century was defined by our ability to kill off deadly bugs, then the 21st will be known as the era in which we learned to get along.
4-5-17 Language heard, but never spoken, by young babies bestows a hidden benefit
Language heard, but never spoken, by young babies bestows a hidden benefit
Babies who heard Korean spoken in their first six months of life were better able to pick up the language later as adults, a study finds. The results show how early language exposure patterns the brain in ways that may not be revealed for decades, if ever. The way babies learn to speak is nothing short of breathtaking. Their brains are learning the differences between sounds, rehearsing mouth movements and mastering vocabulary by putting words into meaningful context. It’s a lot to fit in between naps and diaper changes. A recent study shows just how durable this early language learning is. Dutch-speaking adults who were adopted from South Korea as preverbal babies held on to latent Korean language skills, researchers report online January 18 in Royal Society Open Science. In the first months of their lives, these people had already laid down the foundation for speaking Korean — a foundation that persisted for decades undetected, only revealing itself later in careful laboratory tests.
4-5-17 Cheap stroke drug boosts pancreatic cancer survival in mice
Cheap stroke drug boosts pancreatic cancer survival in mice
A drug used in Asia for decades to treat strokes has been found to soften the armour of pancreatic tumours, making them vulnerable to chemotherapy. A drug that is already used to treat strokes can significantly prolong the survival of mice with pancreatic cancer. Pancreatic cancer has the worst survival rate of any major cancer. The standard chemotherapy combination of gemcitabine and nab-paclitaxel (Abraxane) only keeps patients alive for an average of nine months. Treatment is difficult because pancreatic tumours are protected by an armour of connective tissue, blood vessels and immune cells, known collectively as the stroma. Now, a team led by Paul Timpson and Marina Pajic at the Garvan Institute of Medical Research in Sydney, Australia, has shown that the stroke drug fasudil can weaken this stroma, making it easier for chemotherapy drugs to enter the tumour. In mice with pancreatic cancer, three days of fasudil treatment prior to standard chemotherapy increased survival time by 47 per cent. If this benefit translated to humans, it would increase average survival from 9 to 13 months. “It doesn’t sound like much, but because the baseline success for pancreatic cancer treatments is so low, any improvement is fantastic,” says Timpson.
4-5-17 World is home to '60,000 tree species'
World is home to '60,000 tree species'
There are 60,065 species of trees in the world, according to a comprehensive study of the world's plants. Botanical Gardens Conservation International (BGCI) compiled the tree list by using data gathered from its network of 500 member organisations. It hopes the list will be used as a tool to identify rare and threatened species in need of immediate action to prevent them becoming extinct. Details of the study appear in the Journal of Sustainable Forestry. The data revealed that Brazil was the nation with the greatest number of tree species, home to 8,715 varieties. Apart from the polar regions, which have no trees, the near-Arctic region of North America had the fewest number of species, with less than 1,400. Another fact to emerge from the data was that more than half of the species (58%) were only found in one country, suggesting that they were vulnerable to potential threats, such as deforestation from extreme weather events or human activity. About 300 species have been identified as critically endangered as they had fewer than 50 individuals remaining in the wild.
4-5-17 CRISPR had a life before it became a gene-editing tool
CRISPR had a life before it became a gene-editing tool
Natural CRISPR systems immunize bacteria from invading viruses, and more. Bacteria and archaea armed with CRISPR systems have been at war with viruses for eons. Hordes of viruses known as phages would assault a bacterium to turn it into a virus-making factory. It is the dazzling star of the biotech world: a powerful new tool that can deftly and precisely alter the structure of DNA. It promises cures for diseases, sturdier crops, malaria-resistant mosquitoes and more. Frenzy over the technique — known as CRISPR/Cas9 — is in full swing. Every week, new CRISPR findings are unfurled in scientific journals. In the courts, universities fight over patents. The media report on the breakthroughs as well as the ethics of this game changer almost daily. But there is a less sequins-and-glitter side to CRISPR that’s just as alluring to anyone thirsty to understand the natural world. The biology behind CRISPR technology comes from a battle that has been raging for eons, out of sight and yet all around us (and on us, and in us). The CRISPR editing tool has its origins in microbes — bacteria and archaea that live in obscene numbers everywhere from undersea vents to the snot in the human nose. For billions of years, these single-celled organisms have been at odds with the viruses — known as phages — that attack them, invaders so plentiful that a single drop of seawater can hold 10 million. And natural CRISPR systems (there are many) play a big part in this tussle. They act as gatekeepers, essentially cataloging viruses that get into cells. If a virus shows up again, the cell — and its offspring — can recognize and destroy it. Studying this system will teach biologists much about ecology, disease and the overall workings of life on Earth.
4-4-17 Engineered immune cells boost leukemia survival for some
Engineered immune cells boost leukemia survival for some
Patients with low disease load had best outcomes in first long-term look. Doctors can engineer a patient’s own immune cells to kill cancer cells. These engineered cells, called CAR-T cells, were effective for some people against relapses of leukemia over the long term. Immune cells engineered to hunt and destroy cancer cells may help some people with acute lymphoblastic leukemia (ALL) live much longer. Outcomes depended upon disease severity before treatment, oncologist Jae Park reported April 3 at the American Association for Cancer Research annual meeting. In ALL — expected to strike 5,970 people and kill 1,440 in the United States in 2017 — immune cells called B cells grow out of control in bone marrow and can spread to other tissues. Overall, five-year survival rates are 71 percent. But fewer than 10 percent of people survive for five years after a relapse of the cancer, said Park of Memorial Sloan Kettering Cancer Center in New York City.
4-4-17 Evidence of ancient 'geological Brexit' revealed
Evidence of ancient 'geological Brexit' revealed
The UK has now started the formal process of leaving the EU, but scientists say they have evidence of a much earlier "Brexit". They have worked out how a thin strip of land that once connected ancient Britain to Europe was destroyed. The researchers believe a large lake overflowed 450,000 years ago, damaging the land link, then a later flood fully opened the Dover Strait. The scars of these events can be found on the seabed of the English Channel. The study is published in the journal Nature Communications.
4-4-17 Is consciousness just an illusion?
Is consciousness just an illusion?
The cognitive scientist Daniel Dennett believes our brains are machines, made of billions of tiny "robots" - our neurons, or brain cells. Is the human mind really that special? In an infamous memo written in 1965, the philosopher Hubert Dreyfus stated that humans would always beat computers at chess because machines lacked intuition. Daniel Dennett disagreed. A few years later, Dreyfus rather embarrassingly found himself in checkmate against a computer. And in May 1997 the IBM computer, Deep Blue defeated the world chess champion Garry Kasparov. Many who were unhappy with this result then claimed that chess was a boringly logical game. Computers didn't need intuition to win. The goalposts shifted. Daniel Dennett has always believed our minds are machines. For him the question is not can computers be human? But are humans really that clever? In an interview with BBC Radio 4's The Life Scientific, Dennett says there's nothing special about intuition. "Intuition is simply knowing something without knowing how you got there".
4-4-17 This scientific theory explains why people keep quiet on things that matter
This scientific theory explains why people keep quiet on things that matter
If you're like most Americans, you're probably at least a little worried about climate change — and you probably aren't talking about it. Research has shown that two-thirds of people in the U.S. say they're "moderately interested" or "very interested" in global warming; at the same time, around 70 percent say they rarely or never broach the subject with the people close to them. It's a paradox that also doubles as an explanation: Climate scientists have suggested that the reason people don't discuss climate change is simply because they don't hear it being discussed, a phenomenon sometimes referred to as the "spiral of silence." The term was coined by German political scientist Elisabeth Noelle-Neumann in her book The Spiral of Silence: Public Opinion — Our Social Skin, in which she observed that silence can manifest itself in different ways: Both people who hold majority opinions and those in the minority will often keep quiet on issues that are important to them, but they'll do it for different reasons. But both of those reasons, explains Elizabeth Suhay, a political scientist who studies conformity, stem from a misjudgment about the prevalence of their opinions. "The majority just assumes that everybody thinks like them," she says, "and people in the minority think they're the only ones."
4-4-17 'Surprise' discovery of Europe's first cave-dwelling fish
'Surprise' discovery of Europe's first cave-dwelling fish
Pink, scaleless and with declining vision, the cave loach is the first ever example of a fish found living in a cave in Europe. Researchers say the creature was found by divers in a huge underground cavern in southern Germany. Experts believe that these loaches are the most northerly species of cave fish ever discovered. They think they separated from surface-dwelling fishes some time over the past 20,000 years.
4-3-17 First ever cavefish discovered in Europe evolved super-fast
First ever cavefish discovered in Europe evolved super-fast
A remote underground cave system in Germany has yielded a ghost-like cavefish that evolved as recently as 16,000 years ago. Europe’s first cavefish has been discovered by a cave diver in Germany. The pale-coloured loach, shown above, is thought to have diverged from surface fish as glaciers from the last ice age receded some 16,000 to 20,000 years ago. “Our first genetic studies, plus knowledge of the geological history of the region, suggest the cave loach population is amazingly young, certainly not older than 20,000 years,” says Jasminca Behrmann-Godel at the University of Konstanz in Germany, who led the team that analysed the fish. “Despite this short time span, the fish show trademark adaptions to cave life compared with loaches from surface locations nearby, including a pale body colouration, much smaller eyes, plus larger nostrils and barbels.” It shows that adaptation to these subterranean habitats can be fast, and just a few thousand years might be enough for a fish to adapt to cave life, says Behrmann-Godel. “Cavefish could exist virtually everywhere in principle, and there’s no good reason to expect long evolution times for them to adapt to cave environments,” she says.
4-3-17 Out-of-body experiments show kids’ budding sense of self
Out-of-body experiments show kids’ budding sense of self
Children as young as age 6 have body awareness needed to identify with avatar of themselves. A sense of being a self in one’s own body develops in phases over many years, beginning by age 6, a new study finds. Researchers studied kids and adults who felt a touch on their actual backs as they saw a virtual version of themselves touched on the back with a stick. Kids can have virtual out-of-body experiences as early as age 6. Oddly enough, the ability to inhabit a virtual avatar signals a budding sense that one’s self is located in one’s own body, researchers say. Grade-schoolers were stroked on their backs with a stick while viewing virtual versions of themselves undergoing the same touch. Just after the session ended, the children often reported that they had felt like the virtual body was their actual body, says psychologist Dorothy Cowie of Durham University in England. This sense of being a self in a body, which can be virtually manipulated via sight and touch, gets stronger and more nuanced throughout childhood, the scientists report March 22 in Developmental Science.
4-3-17 Prehistoric humans made jewellery out of exotic island animals
Prehistoric humans made jewellery out of exotic island animals
Pendants made from the finger bone of a bear cuscus and beads from the tooth of a babirusa pig show the artistry of humans in Australasia 30,000 years ago. Stone Age style was all about strange animal necklaces and bracelets. The first humans to cross the ocean from Asia to Australia fashioned jewellery from the bones, teeth and shells of the unfamiliar creatures they discovered on islands along the way. The finding adds to evidence that early inhabitants of Australasia had symbolic practices that were just as rich as those of their European counterparts. Modern humans first ventured out of Africa at least 60,000 years ago, with some travelling west towards Europe. Others spilled east, spreading to the southern edge of mainland Asia, before building boats and island-hopping to Australia about 50,000 years ago. During this migration, they stumbled across a dizzying array of new and exotic plants and animals that differed from island to island. Emerging evidence suggests that they rapidly integrated these species into their symbolic lives. Last year, for example, archaeologists reported that 42,000-year-old jewellery beads made from the shells of Nautilus pompilius – a South Pacific mollusc – had been found in a cave on the island of Timor. Now, a team led by Adam Brumm and Michelle Langley at Griffith University in Queensland, Australia, has dug up ancient ornaments fashioned out of the bones and teeth of native animals on the island of Sulawesi, about 900 kilometres north-west of Timor.
4-3-17 Questions raised over 3-parent baby procedure last year
Questions raised over 3-parent baby procedure last year
As more details are published about the first baby born last year using a new mitochondrial replacement therapy technique, some are voicing procedural concerns. Some concerns have been voiced over the way in which a clinic last year created the first three-parent baby born using a new technique. The baby’s birth was exclusively revealed by New Scientist in 2016. John Zhang of the New Hope Fertility Center in New York and his team used a form of mitochondrial replacement therapy to help a woman have a baby without passing on a serious genetic disease carried in the DNA of her mitochondria, the compartments that generate energy in our cells. The method involves placing the DNA from one woman into a donated egg from another, and then fertilising it with sperm. Because the egg contains some mitochondrial DNA from the donor, babies made this way carry genetic material from three different people. The team has now published an account of this procedure and the resulting baby’s health in a peer-reviewed journal, Reproductive BioMedicine Online. It reveals that, seven months after birth, the boy remains healthy, showing no signs of Leigh syndrome – a condition that killed two of his older siblings.
4-2-17 Food odors are more enticing to sleep-deprived brains
Food odors are more enticing to sleep-deprived brains
Activity boost seen in areas linked to olfaction. The brain appears to have a heightened response to food smells when sleep deprived, new research suggests. The nose knows when you’re tired. Sleep deprivation seems to increase the brain’s sensitivity to food smells, researchers reported March 27 at the Cognitive Neuroscience Society’s annual meeting in San Francisco. That might make snacks more enticing — helping explain why people who burn the candle at both ends tend to eat more and gain weight. Adults operating on only four hours of sleep inhaled food odors such as those from potato chips and cinnamon rolls, and nonfood smells like fir trees while undergoing functional MRI scans. (The scientists carefully controlled participants’ food intake throughout the day.) A few weeks later, the same participants repeated the experiment — this time with a full eight hours of sleep.
Total Page Views
115 Evolution News Articles
for April 2017
Evolution News Articles for March 2017