137 Evolution News Articles
for March 2017
Click on the links below to get the full story from its source
3-31-17 More brain differences seen between girls, boys with ADHD
More brain differences seen between girls, boys with ADHD
Cerebellum disparities may help explain behavior contrast between the sexes. In girls, ADHD often causes inattentiveness and distractibility, rather than the disruptive behavior more often seen in boys. These behavioral differences are reflected in brain structure. Girls and boys with attention-deficit/hyperactivity disorder don’t just behave differently. Parts of their brains look different, too. Now, researchers can add the cerebellum to that mismatch. For boys, symptoms of the disorder tend to include poor impulse control and disruptive behavior. Girls are more likely to have difficulty staying focused on one task. Studies show that those behavioral differences are reflected in brain structure. Boys with ADHD, for example, are more likely than girls to display abnormalities in premotor and primary motor circuits, pediatric neurologist Stewart Mostofsky of Kennedy Krieger Institute in Baltimore has reported previously. Now, Mostofsky and colleagues have looked at the cerebellum, which plays a role in coordinating movement. He reported the new findings March 25 at the Cognitive Neuroscience Society’s annual meeting in San Francisco.
3-31-17 GPS ‘turns off’ brain
GPS ‘turns off’ brain
Relying too much on your GPS could deactivate parts of the brain, a new study suggests. Neuroscientists at University College London scanned the brains of 24 people as they navigated simulations of the British capital. Sometimes they had to find their own way, and sometimes they were given turn-by-turn directions similar to those offered by SatNav systems. Activity in the hippocampus—the brain region involved in memory and spatial mapping—increased when participants navigated by themselves. It also stimulated their prefrontal cortex, which is involved in planning and decision making. But when participants were given GPS-like directions, “brain activity in these regions ‘switched off,’” reports Scientific American. This shift could free up mental resources for other tasks, but researchers note that over time the brain’s ability to navigate could suffer. “If you think about the brain as a muscle,” says study leader Hugo Spiers, “then certain activities, like learning maps of London’s streets, are like body building.”
3-31-17 Sleeping well is the best revenge
Sleeping well is the best revenge
Improving the quality of your sleep can make you feel as good as winning the lottery, a new study suggests. British researchers analyzed the slumber patterns of more than 30,500 people over the course of four years and found those who made positive changes in their sleep habits were significantly happier and healthier. In fact, researchers said, the mental and physical advantages of better sleep were similar to improvements observed in British lottery winners two years after they’ve hit a $250,000 jackpot, reports ScienceDaily.com. The researchers note that while people who slept longer registered higher scores on mental health tests, it didn’t necessarily boost their physical health. Better sleep quality, however, had a salutary effect on mind and body alike. On the other hand, sleeping poorly and relying on sleeping pills to get rest correlated to worse physical and emotional health. It’s estimated that more than one-third of adults in the U.S. don’t get enough sleep, which puts them at higher risk of developing diabetes, obesity, depression, and other chronic health issues. More research is needed on how sleep affects long-term quality of life, the scientists said, but the evidence does suggest it’s important. “We are far from demonstrating a causal relationship,” says lead author Nicole Tang. “But the current findings suggest that a positive change in sleep is linked to better physical and mental well-being further down the line.”
3-31-17 The world’s healthiest hearts
The world’s healthiest hearts
The Tsimane people of Bolivia’s Amazon rain forest boast the healthiest hearts in the world, new research shows. Heart attacks and strokes are almost unheard of among these indigenous forager-horticulturalists, who live off their land, growing or killing what they need to survive. A research team visited 83 Tsimane villages and assessed more than 700 volunteers, NBCNews?.com reports. Nearly 90 percent of villagers had no risk for heart disease—the average 80-year-old Tsimane has the cardiovascular system of a 50-something American. The authors attribute the Tsimane’s exceptional heart healthiness to a diet rich in complex carbohydrates like rice, plantains, and corn and a highly active, pre-industrial lifestyle devoid of electricity and other modern conveniences. “Would I live like the Tsimane to reduce my risk of heart disease? No way,” says cardiologist Tim Chico. “But what I would learn from them is that my risk of heart disease is largely determined by what I do, not what I am.”
3-31-17 How climate shaped the nose
How climate shaped the nose
When it comes to your nose, geography was destiny. New research suggests the shape of the human proboscis can be traced to the ways our ancestors adapted to the climate in their particular parts of the world. An international team of scientists used 3-D facial imaging to measure and compare the noses of some 2,600 people from all over the globe, including West Africa, East Asia, Northern Europe, and South Asia. After analyzing the temperatures and humidity levels in these regions, the researchers found that nasal configuration is influenced by natural selection—the process by which species adjust to their environment to survive and reproduce. The nose does more than smell. It moistens and warms inhaled air to protect the lungs and prevent illness. Narrower nostrils do this more efficiently—a trait more important in cold, dry regions. Study subjects whose forebears lived in warm, humid climates tended to have wider nostrils and noses than those from colder climates. The researchers argue their findings could have important health implications. “If nose-shape evolution has indeed been driven by climate, does moving to a different climate increase our risk of respiratory disease?” lead author Arslan Zaidi asks in PopularScience.com. “This is unclear at this point, but important to pursue.”
3-30-17 Getting dengue first may make Zika infection much worse
Getting dengue first may make Zika infection much worse
Cell, mice experiments reveal antibodies gone rogue. A dengue antibody bound to a dengue virus protein, can ease Zika’s entry into cells, a new study finds. Being immune to a virus is a good thing, until it’s not. That’s the lesson from a study that sought to understand the severity of the Zika outbreak in Brazil. Experiments in cells and mice suggest that a previous exposure to dengue or West Nile can make a Zika virus infection worse. “Antibodies you generate from the first infection … can facilitate entry of the Zika virus into susceptible cells, exacerbating the disease outcome,” says virologist Jean K. Lim. Lim and colleagues report the results online March 30 in Science. The study is the first to demonstrate this effect in mice, as well as the first to implicate West Nile virus, notes Sharon Isern, a molecular virologist at Florida Gulf Coast University in Fort Myers.
3-30-17 Destroying a type of brain cell makes mice really chilled out
Destroying a type of brain cell makes mice really chilled out
Taking deep breaths during meditation or yoga can make you feel relaxed, but we don’t know why. Now some extremely chilled-out mice have given us a clue. A new kind of brain cell that links breathing rate to alertness has been found in mice. Destroying these neurons made mice very calm and may explain why deep breathing – such as in yoga or meditation – makes us feel relaxed. Kevin Yackle at the University of California, San Francisco, and his team have dubbed these brain cells “pranayama neurons” in reference to a yoga breathing exercise. They identified them using an existing database of gene activity in different mouse brain cells. The pranayama neurons stood out because they are the only type of brain cell in the hindbrain that makes two particular proteins. There are only 350 of these neurons in a mouse’s brain, located at its base in a region responsible for controlling breathing. The researchers found that the cells connect to a nearby brain area known to control alertness. They then genetically engineered three mice so a drug could be used to kill their pranayama neurons, but leave other brain cells untouched. Once these neurons had been destroyed, the animals took more slow breaths. They also spent less time exploring and sniffing, and more time grooming themselves, becoming “super-chilled out”, says Yackle.
3-30-17 New tyrannosaur had a sensitive side
New tyrannosaur had a sensitive side
Bones, hints of nerve network point to snout’s ability to sense touch, temperature. The coarse skull bones of the newly identified Daspletosaurus horneri (top left) hint that the tyrannosaur had sensory organs in its skin, seen as black dots on the snout scales. Behind their ferocious façade, tyrannosaurs were probably a bit touchy-feely. A new species of tyrannosaur may have had highly sensitive organs in its face that could detect touch and temperature, researchers report March 30 in Scientific Reports. Several skulls of the newly identified species, Daspletosaurus horneri, which lived about 75 million years ago and grew about 9 meters long, have been dug up in northern Montana since the early 1990s. D. horneri’s facial bones were lumpy and coarse, like “mud that people have walked through a dozen times,” says study coauthor Thomas Carr, a vertebrate paleontologist at Carthage College in Kenosha, Wis. And nerve holes riddled the dino’s snout and jaw bones. Such texture and wiring is similar to that of crocodilians, close tyrannosaur relatives that have specialized sensory organs in their facial scales. The dino’s head would have been as sensitive as a “giant fingertip,” Carr says, potentially allowing D. horneri to gently pick up its young. All tyrannosaurs probably had these sensory organs, Carr and colleagues suggest.
3-30-17 Weird T. rex forerunner had small horns and crocodile-like snout
Weird T. rex forerunner had small horns and crocodile-like snout
This new species was a ferocious predator with a sensitive side that reigned across North America until T. rex came along. There’s a new tyrannosaur on the block, and it seems it was quite sensitive. This predecessor of T. rex, Daspletosaurus horneri, or “Horner’s frightful lizard”, is named after Jack Horner, the paleontologist famous for his work advising the makers of the Jurassic Park films. Markings left on the fossils of this new species suggest it had a snout covered with scales that could sense pressure and temperature. “Virtually every bone in any skeleton is shaped by surrounding soft tissues,” says Thomas Carr of Carthage College in Wisconson, who led the study. “Soft tissues leave their fingerprints on bones.” The team found that areas on the lower jaw of the tyrannosaur skulls had a bumpy texture that implies they were once covered by armor-like skin similar to a rhino’s. “They’re in patches where the animal would be thrusting its head into a carcass. It looks like it might be protective,” he says. D.horneri has a groove in its jaw for rictal blood vessels, the kind that supply birds’ beaks. Although there’s no evidence the tyrannosaurs had beaks, it could be the early vascular setup for their later evolution, Carr says. They also found that the tyrannosaurs had small ornamental horns in front of their eyes. The skull is also punctuated by lots of small nerve openings, implying that the species had a mask of flat, sensitive scales much like those on a crocodile’s snout.
3-30-17 Tadpoles learn to see with new eyes transplanted on their tails
Tadpoles learn to see with new eyes transplanted on their tails
A migraine drug seems to help nerve cells connect to new eyes implanted into blind tadpoles. The drug may prove useful for wiring up new organs in people. Blind tadpoles have learned to see again, using eyes implanted on their tails. With help from a migraine drug, these eyes were able to grow new connections to the tadpole’s nervous system. The same approach may work in humans, allowing the body to integrate bioengineered organs, say the team behind the work. “If a human had an eye implanted on their back connected to their spinal cord, would the human be able to see out of that eye? My guess is probably yes,” says Michael Levin, at Tufts University in Medford, Massachusetts. Levin is interested in how bioengineered organs might work within human bodies. Teams around the world have already created organs in the lab and implanted them in people, such as tracheas and bladders, and are now working on more complex organs, such as eyes and hearts. But in order for these to work, the organs would have to be connected to the central nervous system, which controls the body and feeds information back to the brain.
3-29-17 Gene editing of human embryos yields early results
Gene editing of human embryos yields early results
Efforts to cure genetic diseases under way in lab, not ready for clinic. Researchers in China and Texas have used CRISPR/Cas9 to repair disease-causing mutations in viable human embryos. Scientists have long sought a strategy for curing genetic diseases, but — with just a few notable exceptions — have succeeded only in their dreams. Now, though, researchers in China and Texas have taken a step toward making the fantasies a reality for all inherited diseases. Using the gene-editing tool known as CRISPR/Cas9, the researchers have successfully edited disease-causing mutations out of viable human embryos. Other Chinese groups had previously reported editing human embryos that could not develop into a baby because they carried extra chromosomes, but this is the first report involving viable embryos (SN Online: 4/8/16; SN Online: 4/23/15). In the new work, reported March 1 in Molecular Genetics and Genomics, Jianqiao Liu of Guangzhou Medical University in China and colleagues used embryos with a normal number of chromosomes. The embryos were created using eggs and sperm left over from in vitro fertilization treatments. In theory, the embryos could develop into a baby if implanted into a woman’s uterus. (Webmaster's comment: Again China takes the lead!)
3-29-17 Lyme disease is set to explode and we still don’t have a vaccine
Lyme disease is set to explode and we still don’t have a vaccine
A new prediction says 2017 and 2018 will see major Lyme disease outbreaks in new areas. This could lead to lifelong health consequences, so where's the vaccine? BY THE time he had finished his walk through the woods in New York state, Rick Ostfeld was ready to declare a public health emergency. He could read the warning signs in the acorns that littered the forest floor – seeds of a chain of events that will culminate in an unprecedented outbreak of Lyme disease this year. Since that day in 2015, Ostfeld has been publicising the coming outbreak. Thanks to a changing climate it could be one of the worst on record: the ticks that carry the disease have been found in places where it has never before been a problem – and where most people don’t know how to respond. The danger zone isn’t confined to the US: similar signs are flagging potential outbreaks in Europe. Polish researchers predict a major outbreak there in 2018. In theory, Ostfeld’s early warning system gives public health officials a two-year window to prepare. In many other cases, this would be enough time to roll out a vaccination programme. But there is no human vaccine for Lyme disease. Why not? And what can you do to protect yourself in the meantime?
3-29-17 ALS linked to occupational exposure to electromagnetic fields
ALS linked to occupational exposure to electromagnetic fields
People who work as welders, sewing-machine operators, and aircraft pilots may be more likely to develop amyotrophic lateral sclerosis, a motor neurone disease. Workplace exposure to electromagentic fields is linked to a higher risk of developing the most common form of motor neurone disease. Amyotrophic lateral sclerosis (ALS) is a disease that ravages the body’s nerve cells, leaving people unable to control their bodies. People can die as soon as two years after first experiencing symptoms. “Several previous studies have found that electrical workers are at increased risk of ALS,” says Neil Pearce, at the London School of Hygiene and Tropical Medicine. “We don’t know why the risk is higher, but the two most likely explanations involve either electrical shocks, or ongoing exposure to extremely low frequency magnetic fields.” Now an analysis of data from more than 58,000 men and 6,500 women suggests it is the latter. Roel Vermeulen, at Utrecht University in the Netherlands, and his team found that people whose jobs exposed them to high levels of very low frequency magnetic fields were twice as likely to develop ALS as people who have never had this kind of occupational exposure. Jobs with relatively highe extremely low frequency electromagnetic fields levels include electric line installers, welders, sewing-machine operators, and aircraft pilots, says Vermuelen. “These are essentially jobs where workers are placed in close proximity to appliances that use a lot of electricity.”
3-29-17 Sawfish’s fearsome snout evolved to be undetectable to prey
Sawfish’s fearsome snout evolved to be undetectable to prey
The snout of the elusive sawfish doesn’t make vibrations that prey fish can detect as it swims – just like a wind turbine blade through air. Something looked fishy to Sam Evans as he watched a TV show about sawfish. The sawfish’s long, rigid snout – called a rostrum – looked oddly similar to some of the industrial wind turbine blades he had investigated as a professor of engineering at Australia’s University of Newcastle. So he teamed up with biologist David Morgan and fellow engineer Phil Clausen to find out precisely how the sawfish’s rostrum moves underwater. The researchers CT scanned the rostrum of three different species and then tested these 3D models in a computer program to observe water movements around the rostrum. They used existing video footage of the rostrum’s natural movement to ensure the program mimicked it accurately. “These are tools we use every day for engineering problems, but now the technology is able to cross boundaries into biology,” says Clausen. “Essentially, we have the ability to apply engineering principles to something outside the engineering box.” Marine biologists have long known that sawfish use rostrums as weapons to bludgeon their prey, sometimes impaling it on the razor-sharp teeth embedded in them. But Evans and his team found a second feature: the snouts cut through water without creating vibrations — just like wind turbine blades.
3-29-17 Mosquito flight is unlike that of any other insect
Mosquito flight is unlike that of any other insect
Physics of skeeter wingbeats suggests insects may have traded efficiency for alluring buzz. High-speed video and computer modeling detail forces involved in mosquitoes’ wing rotation that help the insects generate enough lift to support their body weight in the air. Mosquitoes take weird insect flight to new heights. The buzzing bloodsuckers flap their long wings in narrow strokes really, really fast — more than 800 times per second in males. That’s four times faster than similarly sized insects. “The incredibly high wingbeat frequency of mosquitoes is simply mind-boggling,” says David Lentink, who studies flight at Stanford University. Mosquitoes mostly hover. Still, it takes a lot of oomph and some unorthodox techniques to fly that slowly. Mosquitoes manage to stay aloft thanks primarily to two novel ways to generate lift when they rotate their wings , Richard Bomphrey and colleagues write March 29 in Nature. The insects essentially recycle the energy from the wake of a preceding wing stroke and then tightly rotate their wings to remain in flight.
3-29-17 Neandertals had an eye for patterns
Neandertals had an eye for patterns
Notches on a raven bone suggests human relatives intentionally created even spacing. Notches carved into a raven’s wing bone by Neandertals include two that were added to create a consistent, possibly symbolic pattern, scientists say. Neandertals knew how to kick it up a couple of notches. Between 38,000 and 43,000 years ago, these close evolutionary relatives of humans added two notches to five previous incisions on a raven bone to produce an evenly spaced sequence, researchers say. This visually consistent pattern suggests Neandertals either had an eye for pleasing-looking displays or saw some deeper symbolic meaning in the notch sequence, archaeologist Ana Majkic of the University of Bordeaux, France, and her colleagues report March 29 in PLOS ONE. Notches added to the bone, unearthed in 2005 at a Crimean rock shelter that previously yielded Neandertal bones, were shallower and more quickly dashed off than the original five notches. But additions were carefully placed, resulting in relatively equal spacing of all notches.
3-29-17 Neanderthal artist revealed in a finely carved raven bone
Neanderthal artist revealed in a finely carved raven bone
Regularly spaced notches on a raven's wing bone appear to have been carved for aesthetic reasons, with implications for Neanderthal intelligence. A bone from a raven’s wing with seven regularly spaced notches carved into it is the strongest evidence yet that Neanderthals had an eye for aesthetics. Evidence that Neanderthals used pigments, buried objects alongside their dead, and collected bird feathers and claws had been taken as signs of behaviours that were once considered unique to our species of Homo sapiens. But interpreting the motives of ancient humans based on their relics is fraught with difficulty. Incisions in bones and stone objects could be the result of butchery or other practical activities, rather than artistic engravings. “It has been proposed that talons and big feathers were used as personal ornaments, but in reality we don’t have any direct evidence that this was the case,” says Francesco d’Errico of the University of Bordeaux, France.
3-28-17 Sarcasm looks the same in the brain whether it's words or emoji
Sarcasm looks the same in the brain whether it's words or emoji
No words needed to convey irony ;-). Brain activity linked to recognizing verbal sarcasm also spikes when reading a sentence that ends with a winky-face emoji. Millennials, rejoice: A winking-face emoji is worth a slew of ironic words. The brain interprets irony or sarcasm conveyed by an emoji in the same way as it does verbal banter, researchers reported March 26 in San Francisco at the Cognitive Neuroscience Society’s annual meeting. Researchers measured brain electrical activity of college students reading sentences ending in various emojis. For example, the sentence “You are such a jerk” was followed by an emoji that matched the words’ meaning (a frowning face), contradicted the words (a smiling face) or implied sarcasm (a winking face). Then the participants assessed the veracity of the sentence—was the person actually a jerk?
3-28-17 The mysterious ways being bilingual changes your brain
The mysterious ways being bilingual changes your brain
Did you know there is more than one type of bilingualism? Over the past few years, you might have noticed a surfeit of articles covering current research on bilingualism. Some of them suggest that it sharpens the mind, while others are clearly intended to provoke more doubt than confidence, such as Maria Konnikova's "Is Bilingualism Really an Advantage?" (2015) in The New Yorker. The pendulum swing of the news cycle reflects a real debate in the cognitive science literature, wherein some groups have observed effects of bilingualism on non-linguistic skills, abilities, and function, and others have been unable to replicate these findings. Despite all the fuss that has been made about the "bilingual advantage," most researchers have moved on from the simplistic "is there an advantage or not" debate. Rather than asking whether bilingualism per se confers a cognitive advantage, researchers are now taking a more nuanced approach by exploring the various aspects of bilingualism to better understand their individual effects. To give an idea of the nuances I am talking about, consider this: There is more than one type of bilingualism. A "simultaneous bilingual" learns two languages from birth; an "early sequential bilingual" might speak one language at home but learn to speak the community language at school; and a "late sequential bilingual" might grow up with one language and then move to a country that speaks another. The differences between these three types are not trivial — they often lead to different levels of proficiency and fluency in multiple aspects of language, from pronunciation to reading comprehension.
3-27-17 A change in diet may have helped our brains get so big
A change in diet may have helped our brains get so big
Many anthropologists think that living in large social groups drove the evolution of bigger brains, but new findings call that into question. There are bones hidden away in almost every cupboard in many of the rooms of New York University's primatology department, and James Higham is keen to explain to me what they can tell us about an important part of our evolution: why we have such big, heavy brains. He shows me hordes of lemur skulls, as well as casts of our extinct relatives. Of particular interest to him are the sizes of their braincases. After studying this feature in primates including monkeys, lemurs and humans, he and his colleagues have presented an intriguing new idea as to why our brains are so large.
3-27-17 Putting bigger brains down to our social nature is half-baked
Putting bigger brains down to our social nature is half-baked
New work on primates bolsters the idea that diet – rather than social complexity – was key to the evolution of our big brains. In the past two million years, humans have experienced a massive increase in brain size, one not seen in any other species. This rapid evolution gave us brains roughly triple the volume of those of our pre-human ancestors. But the intelligence we enjoy as a result would seem to be advantageous for all sorts of species, not just us. So why was ours the only line to go down this route? The social brain hypothesis was a popular answer. It claims that bigger brains and advanced cognitive abilities are primarily an adaptation to social complexities, with natural selection strongly favouring individuals that can outsmart rivals. Some researchers, myself included, have never been especially persuaded by this idea, which gains its principal support from decades-old evidence that primates in bigger groups have larger brains. Large brains in humans supposedly followed from our ancestors living in relatively large groups, according to this argument. A new study now challenges the foundational evidence for this link. The problem is that traditional analyses have been based on too few species, says a team at New York University (NYU). The researchers collected measures of primate brains and sociality from more than 140 primate species, about three times as many as before, and found no correlation between indicators of brain size and measures of sociality such as group size.
3-27-17 Diabetes drug could be the first to reverse the disease
Diabetes drug could be the first to reverse the disease
Rising obesity is leading to a boom in type 2 diabetes. A drug that reverses the condition in obese mice could make it much easier to control the disease. No insulin injections, no avoiding sugar. A daily drug can reverse diabetes symptoms in mice, opening up the possibility of a much easier way for diabetics to keep their blood sugar level within safe limits. In 2016, the number of people living with diabetes in the UK surpassed 4 million – an increase of 65 per cent over the course of a decade. Some 3.5 million have been diagnosed, but 550,000 are thought to have undiagnosed type 2 diabetes, which is linked to being overweight, and can develop later in life. Many people develop type 2 diabetes as they age, as their body’s response to insulin – a hormone that controls how much sugar circulates in our blood – gets weaker. Some people can manage their symptoms by sticking to a restrictive diet, or using drugs to remove sugar from their system, although many of these have side effects, such as weight gain or diarrhoea. These drugs can only help manage the disease – they cannot reverse it. “We don’t have anything that can overcome insulin resistance,” says Emily Burns of the charity Diabetes UK. As a result, many people end up having to inject insulin to make sure excess sugar is removed from their blood. Left untreated, type 2 diabetes can lead to heart and kidney disease, nerve damage, foot ulcers and vision problems.
3-27-17 Math-anxious brains tackle simple problems differently
Math-anxious brains tackle simple problems differently
Research suggests math-savvy people may be better at automating arithmetic. People anxious about doing math use certain brain networks differently when doing arithmetic, which suggests they might use different problem-solving strategies than people who aren’t anxious about math. When faced with simple math problems, people who get jittery about the subject may rely more heavily on certain brain circuitry than math-savvy people do. The different mental approach could help explain why people with math anxiety struggle on more complicated problems, researchers reported March 25 at the Cognitive Neuroscience Society’s annual meeting. While in fMRI machines, adults with and without math anxiety evaluated whether simple arithmetic problems, such as 9+2=11, were correct or incorrect. Both groups had similar response times and accuracy on the problems, but brain scans turned up differences.
3-27-17 Changing clocks twice a year is bad for health and energy use
Changing clocks twice a year is bad for health and energy use
Are you feeling tired today? Much of the UK got up an hour earlier this morning, a change that has been linked to heart attacks and strokes in some countries. Are you feeling tired today? Much of the UK got up an hour earlier than usual this morning, following the start of daylight savings. But there’s evidence that the clocks changing can have much more serious effects too, including heart attacks and strokes. There’s little doubt that British Summer Time (BST) brings benefits, including reducing energy usage nationwide by allowing us to make better use of daylight hours. This has led to repeated calls for BST to last all year round, to cut carbon emissions and let us enjoy more of the country’s limited winter afternoon sunshine. The act of switching to daylight savings every year also seems to harm some people’s health. Studies have found an annual spike in heart attacks in Michigan in the US and strokes in Finland the day after the clocks go forward in spring. Many of these deaths are likely to have been in frail, elderly people who are at the mercy of care staff schedules. But some could be due to loss of sleep: there’s evidence that heart attacks are most common on Mondays, possibly due to sleep lost while readjusting to the schedule of the working week. The UK has tried year-round BST. The result was a large reduction in road casualties between 1968 and 1971, thanks to the lighter evenings, but the experiment was ended due to complaints from northern parts of the UK, where mornings were darker as a result.
3-27-17 Palace remains in Mexico point to ancient rise of centralized power
Palace remains in Mexico point to ancient rise of centralized power
Ruler ruled, lived in, maybe even performed ritual sacrifices in 2,300-year-old structure. An excavated section of a ruler’s palace in southern Mexico that dates to as early as 2,300 years ago. The structure contained areas for conducting government business. Remnants of a royal palace in southern Mexico, dating to between around 2,300 and 2,100 years ago, come from what must have been one of the Americas’ earliest large, centralized governments, researchers say. Excavations completed in 2014 at El Palenque uncovered a palace with separate areas where a ruler conducted affairs of state and lived with his family, say archaeologists Elsa Redmond and Charles Spencer, both of the American Museum of Natural History in New York City. Only a ruler of a bureaucratic state could have directed construction of this all-purpose seat of power, the investigators conclude the week of March 27 in Proceedings of the National Academy of Sciences.
3-27-17 Fossil tracks are Australia's 'Jurassic Park'
Fossil tracks are Australia's 'Jurassic Park'
Scientists have described a remarkable collection of dinosaur tracks on beaches in the Kimberley region of Western Australia. More than 20 different types of fossil footmarks have been captured in sandstone rock. Some are over 1.5m in size, recording the movement of sauropods - the giant beasts with long necks and tails. The trackways, many only visible at low tide, were "globally unparalleled", claimed the lead scientist involved. Steve Salisbury called the 25km-long coastline collection Australia's own Jurassic Park.
3-24-17 Ancient Romans may have been cozier with Huns than they let on
Ancient Romans may have been cozier with Huns than they let on
Despite painting nomadic Huns as ‘barbarians,’ Roman settlers swapped menus with them. A new analysis of diet among the Huns and ancient Romans uses human remains from five Roman Empire frontier sites, including this skull with a stretched-out braincase. The practice of binding children’s heads to elongate the skull is thought to have originated among nomadic Huns. Nomadic warriors and herders known as the Huns are described in historical accounts as having instigated the fifth century fall of the Roman Empire under Attila’s leadership. But the invaders weren’t always so fierce. Sometimes they shared rather than fought with the Romans, new evidence suggests. Huns and farmers living around the Roman Empire’s eastern border, where the Danube River runs through present-day Hungary, borrowed ways of life from each other during the fifth century, say archaeologist Susanne Hakenbeck of the University of Cambridge and colleagues. Nomadic Huns on the Roman frontier raised relatively small numbers of animals and grew some crops, while border-zone farmers incorporated more meat into what had been a wheat- and vegetable-heavy diet, the scientists report March 22 in PLOS ONE. “Our data show that the dietary strategies of the people on both sides of the Roman frontier were not fundamentally different,” Hakenbeck says. (Webmaster's comment: The Hun women also breed with the Roman conquerors. Conquering men are always seen as having better genes than those men who lost.)
3-24-17 Is most cancer just random bad luck? No, lifestyle matters a lot
Is most cancer just random bad luck? No, lifestyle matters a lot
Many cancers are still preventable despite more research highlighting the role of unavoidable random DNA damage, says biologist Darren Saunders. Competing narratives of chance and lifestyle often frame the debate about cancer’s underlying causes. This is based on wildly varying estimates of what proportions of the genetic mutations that characterise the disease are due to internal and external factors. These are frequently misinterpreted as evidence that cancer is either largely down to bad luck or almost entirely preventable. At one end of the spectrum, this can lead patients on a futile path of reflection, trying to pinpoint a specific event or behaviour to blame for their disease. At the other, blaming bad luck risks diluting public health messages that modifiable lifestyle factors are important. The influence of diet, smoking, sun exposure and alcohol consumption are all well-established. The debate hinges on the fact that cancer-causing mutations in our DNA can occur three ways: they can be inherited, produced by random errors when our cells replicate, or by environmental exposures. There is intense interest in understanding the relative contribution of all three.
3-24-17 Vitamin C targets cancer
Vitamin C targets cancer
Most people take vitamin C to fend off a cold, but new research suggests it could also be a possible weapon in the fight against cancer. A team of researchers at the University of Salford in England evaluated seven substances—vitamin C, two natural products, and four experimental cancer drugs—on their ability to block the growth of cancer stem cells, which inhibit chemotherapy and help tumors spread throughout the body. They found that vitamin C did block the growth of cancer cells; in fact, it was 10 times more effective than one of the pharmaceuticals, although it was outperformed by two experimental drugs. The finding adds to previous research indicating that high-dose vitamin C treatments could slow the growth of cancer cells in the prostate, liver, and colon. “Vitamin C is cheap, natural, nontoxic, and readily available,” study co-author Michael Lisanti tells ScienceDaily.com. “To have it as a potential weapon in the fight against cancer would be a significant step.”
3-24-17 Dental plaque reveals Neanderthals’ secrets
Dental plaque reveals Neanderthals’ secrets
Neanderthals are generally portrayed as simpleminded carnivores. But a groundbreaking new study of hominid teeth has found that some of them were dedicated vegetarians and may even have used certain plants as painkillers. Researchers analyzed DNA that had been preserved in dental plaque from three Neanderthals that lived between 42,000 and 50,000 years ago—two from El Sidrón Cave in Spain and one from Spy Cave in Belgium. They found that while the hominid from the grasslands of Spy ate mostly meat, including woolly rhino and wild sheep, some of the inhabitants of the dense forests of El Sidrón probably ate no meat at all, subsisting instead on moss, pine nuts, and fungi. “It is very indicative of a vegetarian diet,” study co-author Laura Weyrich, from the University of Adelaide, tells NPR.org. “Probably the true paleo diet.” The DNA analysis also suggested that one of the El Sidrón Neanderthals may have consumed poplar tree bark—which contains salicylic acid, one of the ingredients in aspirin—to treat pain from a diarrhea-inducing gut parasite and a tooth abscess. The same hominid’s dental plaque also contained traces of the mold used to make penicillin. Another surprising finding was that Neanderthals had mouth bacteria that was acquired from Homo sapiens, which suggests the species were either kissing or sharing food. The discovery, Weyrich says, indicates that relations between modern humans and Neanderthals were probably “much more friendly than anyone imagined.”
3-23-17 Random mutations play large role in cancer, study finds
Random mutations play large role in cancer, study finds
Analysis suggests that cell division produces more malignancy-linked errors than environment, inheritance. As cells divide and grow to replenish and repair organs, accidental mutations may crop up in cancer-associated genes. A new study suggests such random mistakes are the source of 66 percent of mutations in cancer cells across the board. Researchers have identified new enemies in the war on cancer: ones that are already inside cells and that no one can avoid. Random mistakes made as stem cells divide are responsible for about two-thirds of the mutations in cancer cells, researchers from Johns Hopkins University report in the March 24 Science. Across all cancer types, environment and lifestyle factors, such as smoking and obesity, contribute 29 percent of cancer mutations, and 5 percent are inherited. That finding challenges the common wisdom that cancer is the product of heredity and the environment. “There’s a third cause and this cause of mutations is a major cause,” says cancer geneticist Bert Vogelstein.
3-23-17 Chronic pain and depression are linked by brain gene changes
Chronic pain and depression are linked by brain gene changes
At least 40 per cent of people with severe chronic pain develop depression. A mouse study has found changes in brain gene activity that may explain the link. People who have chronic pain are more likely to experience mood disorders, but it’s not clear how this happens. Now a study in mice has found that chronic pain can induce genetic changes in brain regions that are linked to depression and anxiety, a finding that may lead to new treatments for pain. “At least 40 per cent of patients who suffer from severe forms of chronic pain also develop depression at some point, along with other cognitive problems,” says Venetia Zachariou of the Icahn School of Medicine at Mount Sinai in New York. To see if there might be a genetic link between these conditions, Zachariou and her team studied mice with damage to their peripheral nervous system. These mice show symptoms similar to chronic pain in people – they become hypersensitive to harmless touch, and avoid other situations that might also cause them pain.
3-23-17 Edited live vaccine could stop harmful polio outbreaks
Edited live vaccine could stop harmful polio outbreaks
We’re on the brink of eradicating polio, but the virus used as a vaccine can evolve to become dangerous. Now a team has figured out how, and plan to stop it. We’re on the brink of wiping out polio, but the virus used in vaccines keeps evolving to become harmful again. The discovery of how the virus mutates to do this could lead to a safer vaccine. Polio once killed hundreds of thousands of children every year. The disease has largely been brought under control by the oral polio vaccine, which contains a weakened form of the live poliovirus. We do have a vaccine that uses dead virus instead, but this is less effective at spreading immunity. When the weakened live vaccine reaches the intestine, the virus replicates and can be passed on to others in close contact, transmitting immunity to people who haven’t been vaccinated. It’s an effective way of wiping out polio, but it carries a risk. From time to time, the weakened virus re-evolves the ability to cause disease, and spreads rapidly through unvaccinated populations. In the 10 years leading up to 2015, there were around 750 reported cases of paralysis caused by vaccine-derived poliovirus (VDPV) worldwide. A new vaccine in development may put a stop to this. Raul Andino and colleagues at the University of California, San Francisco, have analysed the genes of 424 samples of VDPV from 30 different outbreaks, and compared them with the genetic makeup of the vaccine. They found that in every case, the weakened vaccine virus had undergone the same three evolutionary steps to become virulent again.
3-23-17 Dengue fever spreads in a neighborly way
Dengue fever spreads in a neighborly way
Mapping the transmission of the painful disease could help target efforts to control it. To control the spread of dengue in Bangkok, DDT is sprayed to kill mosquitoes, the primary insect that transmits the virus. Dengue is a bit of a homebody. By mapping the spread of the virus across Bangkok, scientists found that infections were most likely to occur within a few minutes’ walk of the home of the first person infected. Pinpointing where dengue is likely to be transmitted can better focus efforts to stop the spread of the disease, the researchers report in the March 24 Science. “We often think of transmission and infection as occurring in this ubiquitous, pervasive and amorphous way,” says study coauthor Derek Cummings. But there is a pattern to how dengue spreads. This study, he adds, shows that scientists are “starting to have the tools and methods to really track how infectious diseases move across a population.”
3-23-17 Dinosaur crater's clue to origin of life
Dinosaur crater's clue to origin of life
The crater made by the asteroid that killed off the dinosaurs is revealing clues to the origins of life on Earth. Scientists have drilled into the 200km-wide Chicxulub crater now buried under the Gulf of Mexico. They say its rocks show evidence of having been home to a large "hydrothermal system", where hot fluids flowed through cracks and fissures. Similar systems, generated by impacts on the early Earth, could have helped kickstart the first lifeforms. The hydrothermal system at Chicxulub may have been active for two million years or more, the scientists say.
3-22-17 First dinosaurs may have been omnivores in the north hemisphere
First dinosaurs may have been omnivores in the north hemisphere
Largest shake-up of dinosaur family tree in 130 years puts T. rex in a group with herbivores and uproots what we thought we knew about the reptiles. Hips really can lie. In 1888, H. G. Seeley split the dinosaur family tree into two branches based on pelvic bones, but a new analysis suggests a complete rejig of early dinosaur types and challenges assumptions about where the first dinosaurs lived and what they ate. “Maybe we shouldn’t just blindly accept this 130-year-old idea,” says Matthew Baron at the University of Cambridge. “Seeley’s idea, while it was brilliant for his time, it’s arguably archaic. It’s based on very few specimens.” Seeley divided dinosaurs into “bird-hipped” animals, like the herbivorous Stegosaurus and Triceratops, and “reptile-hipped” ones, including carnivores like Tyrannosaurus rex and long-necked herbivores like Apatosaurus. Instead of focusing on the pelvic bone, Baron and his team analysed 457 characteristics of 74 species and found that 21 other anatomical features divide the dinosaurs differently. Some of the common features shared between dinosaurs that were previously thought unrelated include straight thigh bones instead of the S-shaped ones found in some later dinosaurs, shoulder bones three times the length of the forelimb, and the first metatarsal – a long foot bone – not reaching the ankle joint.
3-22-17 Anatomy analysis suggests new dinosaur family tree
Anatomy analysis suggests new dinosaur family tree
Proposal would radically alter century-old groupings. The dinosaur evolutionary tree just got a makeover. One outcome of the proposed rearrangement is that meat-eating evolved twice in dinosaurs (in groups represented by Tyrannosaurus rex, and Staurikosaurus, as did traits associated with plant-eating. The standard dinosaur family tree may soon be just a relic. After examining more than 400 anatomical traits, scientists have proposed a radical reshuffling of the major dinosaur groups. The rewrite, reported in the March 23 Nature, upsets century-old ideas about dinosaur evolution. It lends support to the accepted idea that the earliest dinosaurs were smallish, two-legged creatures. But contrary to current thinking, the new tree suggests that these early dinosaurs had grasping hands and were omnivores, snapping up meat and plant matter alike. “This is a novel proposal and a really interesting hypothesis,” says Randall Irmis, a paleontologist at the Natural History Museum of Utah and the University of Utah in Salt Lake City. Irmis, who was not involved with the work, says it’s “a possibility” that the new family tree reflects actual dinosaur relationships. But, he says, “It goes against our ideas of the general relationships of dinosaurs. It’s certainly going to generate a lot of discussion.”
3-22-17 Major shake-up suggests dinosaurs may have 'UK origin'
Major shake-up suggests dinosaurs may have 'UK origin'
The first dinosaurs may have originated in the Northern Hemisphere, possibly in an area that is now Britain. This is one of the conclusions of the first detailed re-evaluation of the relationships between dinosaurs for 130 years. It shows that the current theory of how dinosaurs evolved and where they came from may well be wrong. This major shake-up of dinosaur theory is published in this weeks's edition of the journal Nature. The reassessment shows that the meat eating beasts, such as Tyrannosaurus rex and Velociraptor, have been wrongly classified in the dinosaur family tree. One of the implications is that dinosaurs first emerged 15 million years earlier than previously believed.
3-22-17 Vision saved by first induced pluripotent stem cell treatment
Vision saved by first induced pluripotent stem cell treatment
A WOMAN in her 80s has become the first person to be successfully treated with induced pluripotent stem (iPS) cells. Laboratory-made retinal cells have protected her eyesight against age-related macular degeneration – a common form of progressive blindness. Unlike other types of stem cell, such as those found in an embryo, induced pluripotent ones can be made from ordinary cells from adults, like skin cells – a discovery that earned a Nobel prize in 2012. Once made, they can be coaxed to form many other types of cell. Now, more than a decade after iPS cells were first created, they have helped someone. Masayo Takahashi at the RIKEN Laboratory for Retinal Regeneration in Kobe, Japan, and her team took skin cells from the woman and turned them into iPS cells. They then encouraged these to form retinal pigment epithelial cells, which support and nourish the retina cells that capture light.
3-22-17 Touches early in life may make a big impact on newborn babies’ brains
Touches early in life may make a big impact on newborn babies’ brains
A wiry electroencephalogram cap captures a baby’s brain response to a light puff of air to the hand. The type and amount of touches a newborn baby gets in the first days of life may shape later responses to touch perception, a study suggests. Many babies born early spend extra time in the hospital, receiving the care of dedicated teams of doctors and nurses. For these babies, the hospital is their first home. And early experiences there, from lights to sounds to touches, may influence how babies develop. Touches early in life in the NICU, both pleasant and not, may shape how a baby’s brain responds to gentle touches later, a new study suggests. The results, published online March 16 in Current Biology, draw attention to the importance of touch, both in type and number. Young babies can’t see that well. But the sense of touch develops early, making it a prime way to get messages to fuzzy-eyed, pre-verbal babies. “We focused on touch because it really is some of the basis for communication between parents and child,” says study coauthor Nathalie Maitre, a neonatologist and neuroscientist at Nationwide Children’s Hospital in Columbus, Ohio.
3-22-17 Moderate drinking may be ‘heart healthy’ but exercise is safer
Moderate drinking may be ‘heart healthy’ but exercise is safer
Another study has found that drinking 14 units or less a week is linked to better cardiovascular health. But drinking alcohol for health is a risky strategy. Once again, a study has confirmed that moderate drinking might be good for the heart – but this benefit vanishes if you drink more than seven pints of lager or equivalent a week. The latest study analysed data from 1.93 million people in the UK, and found that moderate drinkers – who consume 14 units or less a week – were less likely to have angina, heart attacks, and heart failure. They were also less likely to have circulation problems caused by fat in their arteries, aortic aneurysms, and ischaemic strokes – the most common kind of stroke. But drinking more than 14 units – which is approximately seven medium-sized glasses of red wine – a week was found to increase the risk of heart failure, cardiac arrest, ischaemic stroke, and circulation problems.
3-22-17 Old blood can be made young again and it might fight ageing
Old blood can be made young again and it might fight ageing
A protein can boost blood stem cells, making them behave like those of younger people. Is it the key to harnessing young blood’s rejuvenating power? BLOOD from the young seems to have healing powers, but how can we harness them without relying on donors? The discovery of a protein that keeps blood stem cells youthful might help. The rejuvenating properties of young blood came to light in macabre experiments that stitched young and old mice together to share a circulatory system. The health of the older mice improved, while that of the younger ones deteriorated. Other animal studies have since shown that injections of young or old blood have similar effects. This may work in people too. Young blood is being trialled as a treatment for conditions like Alzheimer’s, and aged mice that received injections of blood from human teenagers showed improved cognition, memory and physical activity levels.
3-22-17 Mind the gaps: The holes in your brain that make you smart
Mind the gaps: The holes in your brain that make you smart
A map of the brain’s wiring reveals the spaces may be just as important as the connections – and you have the holes to thank for your most impressive mental feats. IT HAS been described as a “monstrous, beautiful mess”, a “tangled web” and a “dense canopy of tropical branches”. But in reality, it is nothing of the sort. The human brain is a highly organised, efficient machine, no circuit laid without good reason. If it appears tangled, that is only because we haven’t managed to unravel its 100 billion wires and 100 trillion connections well enough to explain how it works. The reward for that feat wouldn’t just be a map of the most complex object in the known universe. Understanding the brain’s connections would begin to teach us how its flashes of electricity add up to a fully conscious experience, one in which our senses, intuition, reasoning and memory interact to give a coherent view of the world. That understanding has long eluded us. But a new approach is providing fresh clues by focusing not on the neural cables but the spaces between them. By applying a curious branch of mathematics more usually applied to exotic states of matter, neuroscientists are revealing a hidden dimension of the brain. It turns out that the wiring between your ears is full of holes – and you might have them to thank for your most impressive mental feats.
3-22-17 Let's focus on the real environmental factors linked to autism
Let's focus on the real environmental factors linked to autism
The publication of Andrew Wakefield's notorious and now discredited research on autism and vaccines in 1998 triggered a surge of worry about vaccine safety. Since then, questions about a purported connection between autism and vaccines have been asked and definitively answered: There is no link. But there are other factors linked to the development of autism that have solid scientific support. A mountain of research has been conducted and published on a possible link between vaccines and autism, with hundreds of advocacy and scientific organizations refuting it. They also point out the public health risk of avoiding vaccinations. Yet the fear this unsubstantiated link has generated has led to the re-emergence of vaccine-preventable diseases such as measles and pertussis. Another consequence of the ongoing media attention paid to the issue is a misunderstanding of the real environmental risk factors associated with autism. During the last year or so, there has been a steady drumbeat of media coverage about autism and vaccines. Politicians, celebrities, the presidential election, film festivals, and mythical conspiracies all contributed to mainstream news and media story lines on the false link between vaccines and autism. Many of them had nothing to do with real science, nor were they the result of research findings that helped families. But during the same period, a dozen new scientific findings were published on legitimate environmental factors, including toxic chemicals, maternal infection during pregnancy, and chronic stress. These rarely made headlines, with the media spotlight remaining on the myth. Yet knowledge and understanding of these real environmental factors could lead to actual therapies or ways to prevent the debilitating symptoms of autism.
3-22-17 This is how to make friends as an adult: 5 secrets backed by science
This is how to make friends as an adult: 5 secrets backed by science
When you were a kid it was a lot easier. In college you almost had to be trying not to make friends. But then you're an adult. You get busy with work. Your friends get busy with work. People get married. Have kids. And pretty soon being "close" means a text message twice a year. You're not alone … Or, actually, the whole point of this is you really may be alone. But you're not alone in being alone. These days we're all alone together. In 1985 most people said they had three close friends. In 2004 the most common number was zero.Friends are important. Nobody would dispute that. But I doubt you know how very important they are. So let's see just how critical friends can be — and the scientifically backed ways to get more of them in your life.
Summing up. Here’s how to make friends as an adult:
- The new starts with the old: Touch base with old friends and leverage your superconnectors.
- Listen, seek similarity, and celebrate: Don't be interesting. Be interested.
- Be vulnerable: Open up a bit. Form an "if-then" profile.
- Don't be a stranger: Check in every two weeks, minimum.
- Start a group: Things that are habits get done. So start a group habit.
3-22-17 Colorful pinwheel puts a new spin on mouse pregnancy
Colorful pinwheel puts a new spin on mouse pregnancy
Award-winning image shows how the immune system influences placental development. A pregnant mouse’s placenta develops differently depending on her immune system. A wheel shows nine developing placentas, some with normal immune cells and some without. This rainbow pinwheel of mouse placentas isn’t just an eye-catching, award-winning image. The differences in color also provide researchers with new clues to how a mother’s immune system may affect her or her baby’s health during pregnancy. The work could lead to earlier diagnosis and treatment of preeclampsia, a common pregnancy complication. Suchita Nadkarni, an immunologist at Queen Mary University of London, used a technique called confocal microscopy to snap individual photos of nine mouse placentas. Arranging the images in a circle is “a really powerful way of seeing what’s going on in the placenta,” she says. The image is one of the winners of the 2017 Wellcome Image Awards, an annual contest for scientific and medical images.
3-21-17 Tiny genetic change lets bird flu leap to humans
Tiny genetic change lets bird flu leap to humans
A change in just a single genetic "letter" of the flu virus allows bird flu to pass to humans, according to scientists. Monitoring birds for viruses that carry the change could provide early warning of risk to people, they say. Researchers at the University of Hong Kong studied a strain of bird flu that has caused human cases in China for several years. Birds carry many flu viruses, but only a few strains can cause human disease. H7N9 is a strain of bird flu that has caused more than 1,000 infections in people in China, according to the World Health Organization. Most cases are linked to contact with infected poultry or live poultry markets. The change in a single nucleotide (a building block of RNA) allows the H7N9 virus to infect human cells as well as birds, say Prof Honglin Chen and colleagues. They say there is "strong interest in understanding the mechanism underpinning the ability of this virus to cause human infections and identification of residues that support replication in mammalians cells is important for surveillance of circulating strains."
3-21-17 Cancer cells cast a sweet spell on the immune system
Cancer cells cast a sweet spell on the immune system
Researchers try to wake up immune cells by focusing on the sugars on the tumor surface. Large surface proteins with chains of sugars on the outside of a cancer cell hide the tumor from immune attack and lull the immune system into a do-nothing trance. Shrink yourself small enough to swoop over the surface of a human cell, and you might be reminded of Earth’s terrain. Fats, or lipids, stay close to the surface, like grasses and shrubs. Proteins stand above the shrubs, as mighty oaks or palm trees. But before you could distinguish the low-lying lipids from the towering proteins, you’d see something else adorning these molecules — sugars. If proteins are the trees, sugars are the mosses that dangle from the branches or, perhaps, the large fronds of the palm. “The cell surface is basically coated with sugars,” says Carolyn Bertozzi, a chemist at Stanford University. “They’re what viruses, bacteria and other cells see first when they touch down on a target cell.”
3-21-17 Life on Earth may have begun as dividing droplets
Life on Earth may have begun as dividing droplets
Shape-shifting blobs of chemicals could split to reproduce, simulations show. Droplets of chemicals within a primordial soup can elongate, split and replicate, new simulations indicate. That process repeats to create new generations of droplets, in a process that mimics reproduction and could reveal the origins of life. In a primordial soup on ancient Earth, droplets of chemicals may have paved the way for the first cells. Shape-shifting droplets split, grow and split again in new computer simulations. The result indicates that simple chemical blobs can exhibit replication, one of the most basic properties of life, physicist Rabea Seyboldt of the Max Planck Institute for the Physics of Complex Systems in Dresden, Germany, reported March 16 at a meeting of the American Physical Society. Within a liquid, small droplets of particular chemicals can separate out, like beads of oil in water. Such globules typically remain spherical, growing as they merge with other drops. But in simulations, Seyboldt and colleagues found that droplets might behave in a counterintuitive way under certain conditions, elongating and eventually dividing into two. If additional droplet material is continuously produced in reactions in the primordial soup, chemicals will accumulate on either end of a droplet, causing it to elongate, the simulations show. Meanwhile, waste products from the droplet are eliminated from the middle, causing the droplet to pinch in and eventually split. The resulting pair of droplets would then grow and split again to create a new generation. In addition to the above reactions, the process requires an energy source, such as heat or chemicals from a hydrothermal vent, to get reactions going.
3-20-17 Deadly, drug-resistant Candida yeast infection spreads in the US
Deadly, drug-resistant Candida yeast infection spreads in the US
So far, 53 Americans have been infected with Candida auris, which can cause organ failure. It is resistant to all three major classes of antifungal drug. An emerging fungus could become the latest hospital-acquired infection we have to worry about. On 16 March, the US Centers for Disease Control and Prevention (CDC) reported that 53 people in the US have been taken ill with Candida auris – most of them in New York state. A further 27 healthy carriers of the fungus have been identified in three states where clinical cases were detected. People at highest risk are those with weak immune systems including premature babies, people with diabetes, people on dialysis, and those who have had recent transplants or other invasive surgery. Unlike most common yeast infections, C. auris doesn’t usually cause thrush, but results in bloodstream, wound or ear infections instead – triggering organ failure in the worst cases. Although information isn’t available for all patients, the death rate could be as high as 60 per cent. However, because patients usually contract the infection while hospitalised with other major illnesses, it’s difficult to be sure whether any deaths can be attributed solely to C. auris.
3-20-17 Genetic switch offers clue to why grasses are survival masters
Genetic switch offers clue to why grasses are survival masters
Cooperation among stomata cells means the plants can respond quickly to change. Scientists have gained new insight into why grasses like Brachypodium distachyon have extra-efficient stomata, adjustable pores on leaves that help regulate the exchange of water and gases between a leaf and the outside world. Grasses have top-notch border control to conserve water in their leaves. Now, scientists have identified the genetic switch that makes them such masters at taking in carbon dioxide without losing water. The find might eventually help scientists create more drought-resistant crop plants, the researchers report in the March 17 Science. Adjustable pores called stomata on the undersides of leaves help plants take in CO2 while minimizing water loss. Like pupils responding to sunlight, plants open and close their stomata in response to changing light, humidity and temperature. Grass stomata can open wider and respond more quickly than those in other plants, which helps grasses photosynthesize more efficiently. This ability might help explain why grasses grow successfully in so many places on Earth, says Brent Helliker, a plant ecologist at the University of Pennsylvania who wasn’t part of the new study. For instance, grasses are particularly well equipped to deal with the rapidly changing weather and strong winds that can hit plains and prairies.
3-20-17 Under lasers, a feathered dino shows some skin
Under lasers, a feathered dino shows some skin
Geochemical fluorescence method illuminates Anchiornis soft tissue, but some remain skeptical. A next-generation imaging technique called laser-stimulated fluorescence reveals hidden skin in the feathered wing of the Jurassic dinosaur Anchiornis. What happens when you shoot lasers at a dinosaur fossil? Some chemicals preserved in the fossil glow, providing a nuanced portrait of the ancient creature’s bones, feathers and soft tissue such as skin. Soft tissue is rarely preserved in fossils, and when it is, it can be easily obscured. A technique called laser-stimulated fluorescence “excites the few skin atoms left in the matrix, making them glow to reveal what the shape of the dinosaur actually looked like,” says Michael Pittman, a paleontologist at the University of Hong Kong. Pittman and colleagues turned their lasers on Anchiornis, a four-winged dinosaur about the size of a pigeon with feathered arms and legs. It lived around 160 million years ago during the Jurassic Period. The researchers imaged nine specimens under laser light and used the photos to reconstruct a model of Anchiornis that shows an exceedingly birdlike body, the team writes March 1 in Nature Communications.
3-20-17 3D-printed bacteria could make bespoke graphene-like materials
3D-printed bacteria could make bespoke graphene-like materials
3D-printing bacterial ink onto sheets of graphene oxide could make precise patterns of highly-conductive material in a cheaper and easier way. How do you make a bespoke material with graphene-like properties? By putting bacteria to work using a 3D printer. Such bacteria could create brand new materials. For example, if you could use bacteria to print a substance resembling graphene – the 2D material made of single-atom layers of carbon – the end product might have similar desirable properties. When placed on sheets of graphene oxide, certain bacteria can turn it into a reduced version of the compound, which shares many properties with graphene but is easier to produce in large amounts. The bacteria do this by pulling oxygen atoms off the material as they metabolise. Reduced graphene oxide is normally made with the help of powerful chemicals or extreme heat, but the microbe-produced version is much cheaper and more environmentally friendly, says Anne Meyer at the Delft University of Technology in the Netherlands. “The more you reduce [graphene oxide], the closer it is to graphene,” she says. “It’s very easy – it takes place at room temperature in some sugar water.”
3-20-17 Sperm swimming technique 'all down to simple maths'
Sperm swimming technique 'all down to simple maths'
How an individual sperm swims, against all the odds, through fluid to reach the fallopian tubes has been revealed - and it's all about rhythm. Researchers from the UK and Japan found that the head and tail movements of sperm made patterns similar to the fields that form around magnets. And these help to propel sperm towards the female egg. Knowing why some sperm succeed and others fail could help treat male infertility, the researchers said. More than 50 million sperm embark on the journey to fertilise an egg when a man and woman have sex. About 10 reach the finish line - but there can only be one winner. The journey is treacherous, says study author Dr Hermes Gadelha. "Every time someone tells me they are having a baby, I think it is one of the greatest miracles ever - but no-one realises," says Dr Gadelha, a lecturer in applied mathematics at the University of York.
3-18-17 'Healthiest hearts in the world' found
'Healthiest hearts in the world' found
The healthiest hearts in the world have been found in the Tsimane people in the forests of Bolivia, say researchers. Barely any Tsimane had signs of clogged up arteries - even well into old age - a study in the Lancet showed. "It's an incredible population" with radically different diets and ways of living, said the researchers. They admit the rest of the world cannot revert to a hunter-gathering and early farming existence, but said there were lessons for all of us.
3-17-17 South American group has the healthiest arteries ever seen
South American group has the healthiest arteries ever seen
Some elderly adults of Tsimane people in Bolivia have arteries so free from disease that they resemble those people in the US who are more than 20 years younger. The Tsimane people of the Bolivian Amazon have the healthiest arteries of any population yet studied. Researchers who examined more than 700 men and women from the group found that almost 90 per cent of people had clear arteries, indicating no risk of heart disease. Even older people showed excellent health. Almost two thirds of people over the age of 75 were nearly free of risk for heart disease, and just 8 per cent had a moderate-to-high risk level. The prevalence of moderate-to-high risk for heart disease is five-fold greater in US adults. One 80-year-old had arteries so healthy that they resembled those of people more than twenty years younger living in the US. “The Tsimane indigenous South Americans have the lowest prevalence of coronary atherosclerosis of any population yet studied,” says Hillard Kaplan, at the University of New Mexico.
3-17-17 Smartphones may be changing the way we think
Smartphones may be changing the way we think
Those attention-grabbing digital devices are like a new appendage. How are they changing us? Smartphones offer ways to connect, store data and get directions. But what exactly digital tech does to our brains is still an unanswered question. Not too long ago, the internet was stationary. Most often, we’d browse the Web from a desktop computer in our living room or office. If we were feeling really adventurous, maybe we’d cart our laptop to a coffee shop. Looking back, those days seem quaint. Today, the internet moves through our lives with us. We hunt Pokémon as we shuffle down the sidewalk. We text at red lights. We tweet from the bathroom. We sleep with a smartphone within arm’s reach, using the device as both lullaby and alarm clock. Sometimes we put our phones down while we eat, but usually faceup, just in case something important happens. Our iPhones, Androids and other smartphones have led us to effortlessly adjust our behavior. Portable technology has overhauled our driving habits, our dating styles and even our posture. Despite the occasional headlines claiming that digital technology is rotting our brains, not to mention what it’s doing to our children, we’ve welcomed this alluring life partner with open arms and swiping thumbs. Scientists suspect that these near-constant interactions with digital technology influence our brains. Small studies are turning up hints that our devices may change how we remember, how we navigate and how we create happiness—or not. (Webmaster's comment: They've turned us into adrenaline junkies. Worse they've made being "liked" more important than having an independent mind.)
3-17-17 Autism genes discovered
Autism genes discovered
Scientists attempting to crack the genetic code of autism have identified 18 new genes associated with the condition. In the largest DNA study of its kind, a team from Toronto’s Hospital for Sick Children analyzed the complete genome sequences of more than 5,000 people from 2,066 families that have children with autism. They found 61 genes that could be linked to the neurodevelopmental disorder, 43 of which had been identified in previous research. On average, the study found, people with autism carry 74 unique genetic mutations that could cause their symptoms. All of the genes newly linked to the condition are involved in brain cell development and communication; researchers say many of them could be altered with medication. The finding could potentially lead to more individualized treatments for those with autism. “With each new gene discovery,” the study’s co-author, Mathew Pletcher, tells NBCNews.com, “we’re able to explain more cases of autism, each with its own set of behavioral effects and many with associated medical concerns.”
Procreating, after researchers in France found that having children increases life expectancy by about two years, especially for widowed or divorced older men. The scientists speculate that elderly parents benefit from the social and financial support that their adult offspring can provide.
3-17-17 ‘Dubiofossils,’ or the real deal?
‘Dubiofossils,’ or the real deal?
Geologists claim they have found the world’s oldest fossils—but many of their colleagues aren’t convinced, reports The New York Times. An international team of researchers found the collection of microscopic tubes and filaments etched into ancient sedimentary rocks on the eastern shore of Hudson Bay in Canada. They believe these strange patterns are the remains of iron-eating bacteria that lived in hydrothermal vents on the ocean floor between 3.8 billion and 4.3 billion years ago. If that’s confirmed, it would suggest that life on Earth began much sooner after the birth of the planet—relatively speaking—than scientists thought. The oldest fossil previously discovered dates back to about 3.5 billion years ago. But skeptics have described these rocks as “dubiofossils”—fossil-like structures that weren’t actually living entities. They argue that the distinct patterns could have formed through the compression of sedimentary rocks, and that bacteria would have had to be even smaller to withstand the low-oxygen conditions of early Earth. “It may be many years before a consensus is reached,” says David Wacey of the University of Western Australia. “But this is how science progresses.”
3-16-17 Premature babies’ brains respond differently to gentle touching
Premature babies’ brains respond differently to gentle touching
Babies born very early miss out on weeks of development in the womb and experience painful procedures. This seems to alter their response to touch. A gentle touch can make all the difference. Premature babies – who miss out on the sensory experiences of late gestation – show different brain responses to gentle touch from babies that stay inside the uterus until term. This could affect later physical and emotional development, but regular skin-to-skin contact from parents and hospital staff seem to counteract it. Infants who are born early experience dramatic events at a time when babies that aren’t born until 40 weeks are still developing in the amniotic fluid. Premature babies are often separated from their parents for long periods, undergo painful procedures like operations and ventilation, and they experience bigger effects of gravity on the skin and muscles. “There is substantial evidence that pain exposure during early life can cause long-term alterations in infant brain development,” says Rebeccah Slater at the University of Oxford. But it has been less clear how gentle touches shape the brains of babies, mainly because the brain’s response to light touch is about a hundredth of that it has to pain, so it’s harder to study.
3-16-17 Recoded organism paves way to new genetic language of life
Recoded organism paves way to new genetic language of life
A new technique has allowed a quicker way of recoding genetic information, which could allow us to design fresh life forms with useful properties from scratch. A form of life that uses a fresh genetic “language” could be just a few years away. This comes after geneticists used a new technique to recode 5 per cent of the Salmonella bacterium’s genome, introducing a record number of engineered changes into a single organism. Now the race is on to recode the entire genome and put the microbes to work. Genome recoding is seen by many as the next big thing in genetic engineering. Among other things, it offers geneticists a way to engineer the proteins produced by organisms and give them new properties – allowing the creation of proteins that don’t exist in nature, and potential uses in new types of drugs and vaccines. Standard proteins are built from 20 amino acids, which are in turn coded for by “codons” – runs of three DNA “letters” in the genetic code (TTT, TTC, and so on). It’s possible to produce 64 distinct codons, meaning there is a lot of redundancy in the system because amino acids are usually coded for by more than one codon. The amino acid leucine, for example, is produced by six different codons. That redundancy could be used to our advantage. For instance, if an entire genome was recoded so that leucine was produced by just one codon, it would free up five others that could be reassigned to produce brand new amino acids beyond the 20 natural ones, potentially leading to new commercially useful proteins.
3-16-17 Robot eavesdrops on men and women to see how much they talk
Robot eavesdrops on men and women to see how much they talk
Women speak more when they’re talking to a woman rather than a man, finds a robot with a fur hat that studied conversations between men, women and children. Who would you get to observe differences in how men, women and children interact? A robot in a fur-lined hat, of course. Experiments using a robotic head, called Furhat, aimed to uncover inequalities in people’s participation when working on a shared activity, and see if a robot could help redress the balance. They revealed that when a woman is paired in conversation with another woman, she speaks more than if paired with a man. And two men paired together speak less than two women. But this only holds for adults. “Surprisingly, we didn’t find this same pattern for boys and girls. Gender didn’t make much difference to how much children speak,” says Gabriel Skantze at the KTH Royal Institute of Technology in Stockholm, Sweden, who is also one of the robot’s creators. Furhat interacted with 540 visitors at the Swedish National Museum of Science and Technology over nine days. Two people at a time would sit at an interactive table with a touchscreen opposite the robot. They were asked to play a game that involved sorting a set of virtual picture cards, such as arranging images of historical inventions in chronological order. The people worked with the robot to try to solve the task. During this time, the robot’s sensors tracked how long each person spoke for. “This turned out to be a really nice opportunity to study the differences between men and women, and adults and children,” says Skantze.
3-16-17 These fish are evolving right now to become land-dwellers
These fish are evolving right now to become land-dwellers
The threat of predation makes the blenny fish seek refuge outside of water, where they are safer, perhaps retracing steps of first land-dwelling animals. It’s a literal case of fish out of water. Blenny fish in the South Pacific Ocean are gradually relocating to land to escape their aquatic predators, in an example of evolution in action. Fish first began crawling onto dry land about 400 million years ago, kicking off an evolutionary chain of events that led to humans. But their reasons for exiting the sea have been uncertain. To look for clues, Terry Ord at the University of New South Wales in Australia and his colleagues have been studying several species of blenny fish or ‘blennies’ at Rarotonga, the largest of the Cook Islands. At low tide, blennies are commonly found swimming in rock pools around the edges of the island. But when high tide moves in, they climb up to dry land and shuffle around the rocks until the tide retreats. The researchers found that this is most likely to avoid predators that swim in with the rising tide – mainly bigger fish like flounders and lionfish. To test what would happen if blennies did not have an escape plan, they made plasticine models and submerged them in the sea. The blenny mimics ended up with puncture wounds, bite marks and chunks missing.
3-15-17 Vision saved by first induced pluripotent stem cell treatment
Vision saved by first induced pluripotent stem cell treatment
A woman with age-related macular degeneration seems to have had her vision stabilised thanks to a transplant of retinal cells generated from her skin. A woman in her 80s has become the first person to be successfully treated with induced pluripotent stem (iPS) cells. A slither of laboratory-made retinal cells has protected her eyesight, fighting her age-related macular degeneration – a common form of progressive blindness. Such stem cells can be coaxed to form many other types of cell. Unlike other types of stem cell, such as those found in an embryo, induced pluripotent ones can be made from adult non-stem cells – a discovery that earned a Nobel prize in 2012. Now, more than a decade after they were created, these stem cells have helped someone. Masayo Takahashi at the RIKEN Laboratory for Retinal Regeneration in Kobe, Japan, and her team took skin cells from the woman and turned them into iPS cells. They then encouraged these to form retinal pigment epithelial cells, which are important for supporting and nourishing the retina cells that capture light for vision.
3-15-17 Mosaic problem stands in the way of gene editing embryos
Mosaic problem stands in the way of gene editing embryos
The first results of gene editing in viable human embryos reveals it works better than we thought, but that there’s another big problem blocking the way. FIXING faulty DNA to create children free from inherited genetic disease is one step closer. The first published results from efforts to use gene editing in viable human embryos have found the technique works better than we thought – but they have also confirmed a major problem. Previous tests found that the CRISPR technique wasn’t very effective at making genetic changes in human embryos, but the latest work fixed mutations in half of the six embryos it was tried on. “It is encouraging,” says Robin Lovell-Badge of the Francis Crick Institute in London, though he warns the numbers are too small to draw strong conclusions. The idea of changing genes to prevent hereditary diseases has been around for a while, but until recently, we didn’t have the tools to do it. Then came CRISPR – a revolutionary method that makes it possible to cheaply and easily edit DNA inside cells. There have been two big obstacles to using the technique, however. The first is safety. As well as correcting a bad mutation, the CRISPR machinery can also make unwanted changes elsewhere in an embryo’s genome, which may lead to cancer. However, this is becoming less of a concern. The technique has been refined to make such “off-target” changes extremely rare, plus there are ways to check embryos for unwanted changes before implanting them into the womb.
3-15-17 How dogs are helping decode the genetic roots of personality
How dogs are helping decode the genetic roots of personality
Thousands of years of selective breeding have turned man’s best friend into the ideal lab rat to study the genetic underpinnings of personality. FIDO loves to cuddle on the sofa, Spot’s a cheeky hound with a good eye for an unguarded slice of roast lamb, and Rover is just the best, most caring babysitter. As dog owners and lovers everywhere will tell you, pooches have personality. Some of that – quite a bit of it, in fact – is down to breeds. Terriers are notorious for their boundless energy. Border collies like to chase things. Pointers point. German shepherds and poodles learn quickly, bulldogs and beagles not so much. All this makes dogs more than just great pets. They’re also ideal subjects for geneticists eager to understand one of the great mysteries still remaining in biology: how complex behaviours are encoded in genes. If scientists can crack the code for dogs, we may be able to understand – and perhaps better manage – not only our loyal companions’ behaviour, but our own as well. Geneticists have known for decades that dogs are perfect for gene prospecting. The comparison may seem a touch unkind, but dog breeds aren’t unlike strains of lab rats: each one is essentially an inbred line reared over generations to be nearly identical clones of each other. That makes both types of animal well suited to studies seeking to understand which gene does what. If you can identify subtle genetic differences between almost identical individuals, you can try to link those to variations in physical appearance, health or behaviour. It’s a far cry from us humans, who tend to be very outbred and unsuited to genetic studies, which is why human genetic studies often focus on small, isolated populations such as Icelanders or the Amish.
3-15-17 Neuroleaks: The secret dialogue between brain and body
Neuroleaks: The secret dialogue between brain and body
Fresh intelligence on the relationship between the brain and the immune system is transforming our view of conditions like epilepsy and Alzheimer's. YOUR brain enjoys a life of privilege. That extraordinary lump of jelly-like tissue between your ears makes up only 2 per cent of your body mass, but demands 25 per cent of your daily energy requirements. It is surrounded by the fortress of your skull to shield it from the outside world, and cushioned in a bath of nourishing fluid. It is even protected from you, insulated from the caprices of the body’s immune system to guard against inflammation. Hold fire on that last one. It turns out that the barrier between the brain and the body’s defence forces isn’t as impassable as we thought. Yes, it stops all sorts of unwanted interlopers, as well as frustrating attempts to get drugs into the brain via the bloodstream. But there is communication across this frontier. Over the past few years, we have begun to see that the brain is in constant dialogue with the immune system and even allows some foreign agents in – discoveries that are shedding new light on everything from epilepsy and Alzheimer’s disease to autism. The brain got its aloof reputation in the late 19th century, when German immunologist Paul Ehrlich noticed something odd. The dyes he was injecting under the skin of lab animals perfused virtually every tissue, turning organs a striking blue – except the brain. Later, people noticed that dye injected into the brain didn’t stain the rest of the body.
3-15-17 Plants have evolved a taste for sand that deters hungry insects
Plants have evolved a taste for sand that deters hungry insects
A mouthful of sand is no fun – and plants seem to know it. Some have evolved to take up silicon and make themselves less tasty for insects. Getting sand in your mouth is an unpleasant experience – and plants seem to know it. Emerging evidence suggests that some plants cultivate a sandy taste to deter herbivores from eating them. Grasses have particularly high levels of silicon – sometimes in excess of 10 per cent of their dry weight – which they suck from the soil. They use some of this to make silica sand particles, which they deploy along their blades making them abrasive, unpalatable and tough to digest. James Ryalls at Western Sydney University in Australia and his colleagues have shown that silicon in the common Australian pasture grass – Phalaris aquatica – significantly reduces its appeal to hungry crickets. They also have some of the first evidence to suggest a knock-on adverse effect for higher predators. The researchers watered half of their P. aquatica specimens with a silicon solution, and the other half with plain water. Those treated with silicon absorbed the element, so that their final silicon content was 1.16 per cent on average, versus 0.86 per cent for untreated plants.
3-14-17 Oldest plant-like fossils discovered are 1.6 billion years old
Oldest plant-like fossils discovered are 1.6 billion years old
The discovery suggests that plants and complex life on Earth are at least 400 million years older than previously thought. THE oldest plant-like fossils ever discovered suggest multicellular life began at least 1.6 billion years ago. Fossils of red algae were found in rocks from Chitrakoot in central India embedded in mats of cyanobacteria, called stromatolites. “We have shown with great probability that plants have a history 400 million years older than previously known,” says Stefan Bengtson, at the Swedish Museum of Natural History in Stockholm. His team found distinct cellular structures inside the fossils characteristic of red algae, which are eukaryotic, meaning they have complex cells, like plants and humans. They also found platelets inside the cells, which could be early chloroplasts, the organelles where photosynthesis takes place (Plos Biology, DOI: 10.1371/journal.pbio.2000735). The early development of the multicellular eukaryotic organisms is disputed due to the scarcity of fossils older than 1 billion years. If the new findings and dating of the fossils are correct, the theory of early complex life on Earth will need to be tweaked. “The tree of life has to be recalibrated,” says Bengtson.
3-14-17 'Oldest plants on Earth' discovered
'Oldest plants on Earth' discovered
The origins of plants may go back hundreds of millions of years earlier than previously thought, according to fossil evidence. Ancient rocks from India suggest plants resembling red algae lived 1.6 billion years ago in what was then shallow sea. The discovery may overturn ideas of when relatively advanced life evolved, say scientists in Sweden. They identified parts of chloroplasts, structures within plant cells involved in photosynthesis. The earliest signs of life on Earth are at least 3.5 billion years old. The first single-celled microscopic life forms evolved into larger multi-cellular eukaryotic organisms (made up of cells containing a nucleus and other structures within a membrane). Therese Sallstedt of the Swedish Museum of Natural History discovered some of the fossils. She described them as "the oldest fossil plants that we know of on Earth in the form of 1.6 billion year old red algae". "They show us that advanced life in the form of eukaryotes (like plants, fungi and us humans/animals) have a much deeper history on Earth than what we previously have thought," she told BBC News.
3-14-17 Making a mistake can put your brain on ‘pause’
Making a mistake can put your brain on ‘pause’
Study shows how one error can lead to another. When people have to make many decisions very quickly, making one mistake can decrease accuracy on the next choice, too. Mistakes can be learning opportunities, but the brain needs time for lessons to sink in. When facing a fast and furious stream of decisions, even the momentary distraction of noting an error can decrease accuracy on the next choice, researchers report in the March 15 Journal of Neuroscience. “We have a brain region that monitors and says ‘you messed up’ so that we can correct our behavior,” says psychologist George Buzzell, now at the University of Maryland in College Park. But sometimes, that monitoring system can backfire, distracting us from the task at hand and causing us to make another error. “There does seem to be a little bit of time for people, after mistakes, where you're sort of offline,” says Jason Moser, a psychologist at Michigan State University in East Lansing, who wasn’t part of the study.
3-13-17 Metabolism may be older than life itself and start spontaneously
Metabolism may be older than life itself and start spontaneously
The discovery that the Krebs cycle, which is essential for life, can occur in the absence of enzymes suggests that life’s origins were surprisingly humble. A set of chemical reactions occurring spontaneously in Earth’s early chemical environments could have provided the foundations upon which life evolved. The discovery that a version of the Krebs cycle, which occurs in most living cells, can proceed in the absence of cellular proteins called enzymes suggests that metabolism is older than life itself. Metabolism describes the fiendishly complex network of reactions that enable organisms to generate energy and the molecules they need to survive, grow and reproduce. The Krebs cycle – also known as the tricarboxylic acid (TCA) cycle – is at the heart of this network. It describes a circular chain of reactions that generates precursors of amino acids and lipids used to build proteins and membranes, and molecules that help the cell to produce its energy. But how did such a complex cycle develop in the first place? One idea is that it began only after RNA, a fundamental building block of life, came into being. Metabolic reactions are catalysed by proteins called enzymes, for which RNA provides the template – at least in modern cells. There is, however, a problem with this “RNA world” hypothesis: if the reactions didn’t already occur immediately in early life forms and provide them with a survival advantage, then there would have been no selective pressure to drive the evolution of enzymes. Furthermore, RNA itself is made from products of metabolism.
3-13-17 Becoming a parent may add a year or two to your life
Becoming a parent may add a year or two to your life
Tracking 1.4 million people has found that having children increases life expectancies by around 1.5 years – perhaps because adult children help elderly parents. Why become a parent? Well for one thing, it may add a few years to your life. A study that tracked 1.4 million people in Sweden born between 1911 and 1925 found that people who had at least one child tended to live longer, and that these benefits lasted up to the age of 80 and over. The analysis found that at the age of 60, men and women with children on average could expect to live for another 18.4 and 23.1 years, respectively. This average life expectancy was 1.5 years higher than women who did not have children, and nearly 2 years higher than childless men. There may be biological reasons why parents live longer. However, because the association between parenthood and increased life expectancy grew stronger with age, and was stronger among non-married people, the researchers think the social support provided by adult children is a likely explanation. The data suggested it was just as beneficial to have a boy as it was to have a girl. Previous studies have suggested that daughters are more likely to help their parents in their old age.
3-13-17 More people could benefit from BRCA breast cancer drugs
More people could benefit from BRCA breast cancer drugs
A type of drug that specifically targets BRCA breast cancers and has relatively few side effects may also benefit some people who don’t have BRCA mutations. Up to a fifth of women with breast cancer may benefit from drugs that are currently reserved for less common cases of the disease, caused by faulty genes. A study by Serena Nik-Zainal, at the Sanger Institute in Cambridgeshire, UK, and her team found that thousands of breast cancers share biochemical similarities to cases caused by BRCA1 and BRCA2 mutations. Faulty BRCA genes are thought to account for between 1 and 5 per cent of the 55,000 cases of breast cancer diagnosed in the UK each year. A type of drug called PARP inhibitors can be used to treat these cancers, and were specifically designed to target tumours with defects in these genes. But Nik-Zainal’s findings suggest 8,000 more people with breast cancer may also respond to these drugs. “Our study shows that there are many more people who have cancers that look like they have the same weaknesses as patients with faulty BRCA1 and BRCA2 genes,” says Nik-Zainal.
3-13-17 People with no mind’s eye may help us boost our creativity
People with no mind’s eye may help us boost our creativity
Electrical stimulation of the brain shows our ability to conjure up mental images is tunable, which may mean we can alter creativity or tame hallucinations. Picture, for a moment, a sunny beach: shimmering blue water, waves rolling on to the shore, colourful umbrellas dotted along the sand. For some people, this act is impossible; they are unable to “see” anything in their minds. The condition, known as aphantasia, affects about 2 per cent of people but remains largely mysterious. Now there is a glimmer of progress in understanding it, with the discovery that electrically stimulating the brain can alter the strength of our mental imagery. Although it’s not yet clear if this will benefit people with aphantasia, it could potentially be used to boost memory, navigational ability and creativity in people who don’t have aphantasia – or to turn down mental imagery in those haunted by dark, intrusive thoughts. The first detailed study of aphantasia was published in 2015, but it wasn’t clear whether people with aphantasia are unable to form mental images to begin with, or whether the conscious brain is somehow blocking access to them. Neither did we know if the strength of mental imagery can be changed.
3-10-17 Cancers striking earlier
Cancers striking earlier
Rates of colon and rectal cancers have dropped significantly among older people since the mid-1980s, but there has been a surprising rise in the prevalence of the diseases among young adults. A new study by the American Cancer Society found that people born in 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer compared with 27-year-olds in 1977. “Every generation after 1950 has a little bit higher risk,” the study’s lead author, Rebecca Siegel, tells NBCNews?.com. “The largest increases are in people in their 20s.” Siegel and her colleagues were unable to establish a cause for this worrisome rise, but they note it has coincided with the growing obesity epidemic and might be related to poor diets. Colon cancer is much less likely to be detected at an early stage in younger people, since colonoscopy, the gold standard for colorectal cancer screening, is usually administered to people 50 and over. In addition, symptoms of colon cancer, such as bloody stool and constipation, are often vague and may not appear right away.
3-10-17 Your brain fills gaps in your hearing without you realising
Your brain fills gaps in your hearing without you realising
The words we hear are often obscured by other noises, but it doesn’t matter. Before we get a chance to notice, our brains guess what we should hear instead. Noise is everywhere, but that’s OK. Your brain can still keep track of a conversation in the face of revving motorcycles, noisy cocktail parties or screaming children – in part by predicting what’s coming next and filling in any blanks. New data suggests that these insertions are processed as if the brain had really heard the parts of the word that are missing. “The brain has evolved a way to overcome interruptions that happen in the real world,” says Matthew Leonard at the University of California, San Francisco. We’ve known since the 1970s that the brain can “fill in” inaudible sections of speech, but understanding how it achieves this phenomenon – termed perceptual restoration – has been difficult. To investigate, Leonard’s team played volunteers words that were partially obscured or inaudible to see how their brains responded. The experiment involved people who already had hundreds of electrodes implanted into their brain to monitor their epilepsy. These electrodes detect seizures, but can also be used to record other types of brain activity.
3-10-17 Maize engineered to silence deadly toxins in poisonous mould
Maize engineered to silence deadly toxins in poisonous mould
Most people on the planet are exposed to aflatoxins from fungi that infect staple crops, but now a GM approach could help change that. It’s a silent killer lurking in common foods. A carcinogenic toxin made by mould kills thousands around the world and forces millions of tonnes of infected crops to be discarded each year. But a new approach could turn off production of the poison even when mould does grow on the crops. Maize plants have been genetically modified to deliver strands of so-called interfering RNA that silence toxin-producing genes in a fungus that commonly grows on the crop. This GM corn can police the Aspergillus fungus on its own cobs and stop it producing poisonous aflatoxin that causes liver disease and cancer. The maize was engineered to express the gene-silencing RNA molecules by Monica Schmidt at the University of Arizona and colleagues. Her team then exposed this GM maize, along with a non-GM variety, to the fungal spores as they grew for a month. The fungus grew on both, but while high levels of toxin were found on the non-GM maize, the toxins were undetectable on the GM plants.
3-10-17 How to grow toxin-free corn
How to grow toxin-free corn
Genetic engineering gives grain tool to stop infecting fungus from making aflatoxins. Genetic engineering gives grain tool to stop infecting fungus from making aflatoxins. Corn genetically engineered to make ninjalike molecules can launch an attack on invading fungi, stopping the production of carcinogenic toxins. These specialized RNA molecules lie in wait until they detect Aspergillus, a mold that can turn grains and beans into health hazards. Then the molecules pounce, stopping the mold from producing a key protein responsible for making aflatoxins, researchers report March 10 in Science Advances. With aflatoxins and other fungal toxins affecting up to 25 percent of crops worldwide, the finding could help boost global food safety, the researchers conclude. “If there’s no protein, no toxin,” says study coauthor Monica Schmidt, a plant geneticist at the University of Arizona in Tucson.
3-10-17 Why we lie
Why we lie
Cast your mind back over the past week. How many times were you tempted to act dishonestly? Perhaps you were given too much change at the pub and deliberated whether to tell the barman. Maybe you thought of lying about your weekend plans in order to avoid an awkward dinner party. Dishonesty is a common temptation. We face such moral dilemmas all the time. They aren't opportunities to act with egregious dishonesty. Rather, these are the prosaic choices that shape much of our daily lives. Since the temptation for dishonesty is always there, we have to continually make decisions about how moral we want our behavior to be. And part of what guides these decisions is how unpleasant being dishonest makes us feel. I recently conducted a study at University College London with Tali Sharot, Dan Ariely and Stephanie C Lazzaro about the temptation to be dishonest. We investigated whether having opportunities to act dishonestly on a repeated basis could affect our readiness to choose dishonesty over and above honesty. The idea is that if someone initially decides to act dishonestly, they will feel bad about it, and so can only bring themselves to be dishonest by a small amount. The next time they act dishonestly, even though it still feels bad, it doesn't feel as bad. As a result, one could be dishonest to a greater extent before reaching a point where they feel bad enough to stop. Understanding why requires connecting two important ideas. The first relates to the role that emotional arousal plays in moral decision-making. The second concerns a feature of how the brain operates when contexts are repeated, known as neural adaptation.
3-10-17 Mystery brain particles may link head injuries to dementia
Mystery brain particles may link head injuries to dementia
Head injuries cause immune cells in the brain to shed microscopic particles, which spread inflammation. This may be why head trauma is linked to dementia. Tiny particles secreted in response to head injury in the brains of mice could help explain how inflammation spreads and ultimately boosts the risk of developing dementia. Head injuries are increasingly being linked to cognitive problems and degenerative brain disease in later life. Mysterious particles a micrometre in diameter have previously been found in the spinal fluid of people with traumatic brain injury, but their function has remained unknown. Now Alan Faden at the University of Maryland School of Medicine in Baltimore and his colleagues have discovered that activated immune cells called microglia secrete such microparticles in response to brain injury, and they seem to spread inflammation well beyond the injury site itself. They can even cause brain inflammation when injected into uninjured animals.
3-9-17 Why overzealous breastfeeding advice can be bad for babies
Why overzealous breastfeeding advice can be bad for babies
An excessive focus on breastfeeding at all costs in the first few days after birth may be harming babies when their mums can’t make enough milk. “Breast is best”. This well-known slogan is meant to convey that babies should be fed exclusively with breast milk. The mantra is so ubiquitous it is widely assumed to be uncontroversial – even though many of the tenets of breastfeeding ideology are in fact contested. While few would deny that breast milk has some health benefits over formula milk – including protection against infections such as diarrhoea – there is debate about their extent, and how they should be weighed against the mother’s well-being if breastfeeding goes badly, not to mention her right to do as she wishes with her own body. Now there is another cause for concern: breastfeeding can sometimes have downsides for babies. It is becoming clear that an excessive focus on breastfeeding at all costs in the first few days after birth can have tragic consequences. “I never imagined that anything like this would exist in medicine,” says Christie del Castillo-Hegyi, a doctor whose baby son became dehydrated after she struggled to produce milk but was discouraged in hospital from supplementing with formula, lest it get in the way of breastfeeding. She believes neonatal dehydration was a factor in his later diagnosis with a seizure disorder. “It goes against all the medical principles of ‘First do no harm’,” she says.
3-9-17 That faddish gluten-free diet may be raising your diabetes risk
That faddish gluten-free diet may be raising your diabetes risk
Going gluten-free without a diagnosis? Growing evidence of potential health harms suggests you might want to think again, says Angry Chef. One thing most food experts agree is that a varied and interesting diet is best. So it is unfortunate that some people have coeliac disease: it condemns them to a lifetime of avoiding the many delicious staple foods made with wheat flour. That’s because people with the disease – thought to number 1 per cent of the population – risk real harm if they ingest gluten, a key part of wheat and related grains. In addition, the less well-understood condition of non-coeliac gluten sensitivity means that a further 4 to 6 per cent may suffer minor problems, although the science behind this is far from definitive. So it’s not surprising that surveys show that around 5 per cent of UK consumers avoid gluten because someone in their household has a reaction to it. Slightly more puzzling are the 8 per cent who say they avoid gluten as part of a “healthier lifestyle”. This figure rises to 10 per cent among the highest socio-economic groups and to 12 per cent for graduates. Despite the claims of a few sensationalist books, there is no evidence that avoiding gluten is in any way beneficial for the vast majority. But somehow a gluten-free diet has become a lifestyle accessory for many, especially the more educated and financially privileged. Ditching gluten if you don’t need to defies logic. It is a mix of proteins, nothing more, and for the vast majority is non-toxic. Given that its elastic, binding properties help give many of our most treasured foods such as bread and pasta their wonderful taste and texture, why avoid it if you don’t have to?
3-9-17 First results of CRISPR gene editing of normal embryos released
First results of CRISPR gene editing of normal embryos released
Until now, CRISPR has only been tested in human embryos unable to develop into children. New results suggest the technique works much better on healthy embryos. A team in China has corrected genetic mutations in at least some of the cells in three normal human embryos using the CRISPR genome editing technique. The latest study is the first to describe the results of using CRISPR in viable human embryos, New Scientist can reveal. While this study – which attempted to repair the DNA of six embryos in total – was very small, the results suggest CRISPR works much better in normal embryos than it did in previous tests on abnormal embryos that could not develop into children. “It is encouraging,” says Robin Lovell-Badge of the Francis Crick Institute in London, who has contributed to several major reports on human genome editing. The numbers are far too low to make strong conclusions though, he cautions. The CRISPR gene editing technique is a very efficient way of disabling genes, by introducing small mutations that disrupt the code of a DNA sequence. CRISPR can also be used to repair genes, but this is much more difficult. Until now, results have only been published from experiments in which the CRISPR technique was used in abnormal embryos, made when two sperm fertilise the same egg. The idea behind this work was that it was more ethical to test the technique on embryos that could never fully develop. (Webmaster's comment: The Chinese roar ahead of us again.)
3-9-17 Five designer chromosomes bring synthetic life a step closer
Five designer chromosomes bring synthetic life a step closer
An international effort to build a carefully edited version of the yeast genome from scratch has reached a milestone by completing five more of 16 chromosomes. The goal of creating a complex organism with a genome designed and built from scratch in the laboratory has come a giant step closer. The team that built the first synthetic yeast chromosome three years ago has now added five more chromosomes, totalling roughly a third of the yeast’s genome. It’s a dramatic scaling-up of our capabilities, and opens the door to large-scale genomic engineering. The world has already seen one synthetic genome, that of the bacterium nicknamed Synthia. However, bacteria have much smaller and simpler genomes than higher organisms such as yeast and humans, known as eukaryotes. Synthesising a eukaryotic genome is thus a much more complex challenge. In 2014, a team led by Jef Boeke, now at New York University Langone Medical Center in New York City, managed to construct a single yeast chromosome. They then replaced one of a living yeast cell’s natural chromosomes with it – the first time this had been done in a eukaryote. Boeke’s team has since edited the entire yeast genome (see “Re-engineering yeast”, below), before farming out the synthesis of the 16 rewritten chromosomes to an international consortium of geneticists and yeast biologists.
3-9-17 Scientists move closer to building synthetic yeast from scratch
Scientists move closer to building synthetic yeast from scratch
Five more chromosomes assembled, 10 to go. With five more synthetic chromosomes built, scientists are closer to creating a synthetic genome for Saccharomyces cerevisiae yeast. Synthetic yeast is on the rise. Scientists have constructed five more yeast chromosomes from scratch. The new work, reported online March 9 in Science, brings researchers closer to completely lab-built yeast. “We’re doing it primarily to learn a little more about how cells are wired,” says geneticist Jef Boeke of the New York University Langone Medical Center. But scientists might also be able to tinker with a synthetic yeast cell more efficiently than a natural one, allowing more precise engineering of everything from antiviral drugs to biofuels. Boeke was part of a team that reported the first synthetic yeast chromosome in 2014 (SN: 5/3/14, p. 7). Now, several hundred scientists in five countries are working to make all 16 Saccharomyces cerevisiae yeast chromosomes and integrate them into living cells. With six chromosomes finished, Boeke hopes the remaining 10 will be built by the end of 2017.
3-9-17 Scratching is catching in mice
Scratching is catching in mice
Like people, mice experience sudden itches after seeing other mice scratch — a boon for studying the neuroscience of contagious behaviors. Catch sight of someone scratching and out of nowhere comes an itch, too. Now, it turns out mice suffer the same strange phenomenon. Tests with mice that watched itchy neighbors, or even just videos of scratching mice, provide the first clear evidence of contagious scratching spreading mouse-to-mouse, says neuroscientist Zhou-Feng Chen of Washington University School of Medicine in St. Louis. The quirk opens new possibilities for exploring the neuroscience behind the spread of contagious behaviors. For the ghostly itch, experiments trace scratching to a peptide nicknamed GRP and areas of the mouse brain better known for keeping the beat of circadian rhythms, Chen and colleagues found. They report the results in the March 10 Science.
3-9-17 DNA provides window into early Aboriginal history
DNA provides window into early Aboriginal history
Scientists have used hair to locate where distinct Aboriginal groups lived in Australia up to 50,000 years ago. The genetic study could help reconnect indigenous families with ancestral communities, according to the University of Adelaide-led study. It shows the first Australians spread rapidly before largely spending continuous time in distinct areas. The research is an important step in learning more about ancestry prior to European settlement, the authors said. It again confirmed that Aboriginal Australians descended from a single population that arrived 50,000 years ago from New Guinea, when it was joined to Australia.
3-9-17 Oldest crocodile eggs discovered in dinosaur nest
Oldest crocodile eggs discovered in dinosaur nest
The oldest crocodile eggs known to science have been discovered in the cliffs of western Portugal. They are so well preserved that they give an insight into the "mother croc" that laid them 152 million years ago. The prehistoric crocodile ancestor would have spanned two metres, based on the size of the larger eggs, say palaeontologists. Crocodiles arose some 200 million years ago, when they prowled the land with early dinosaurs. Today, they are found throughout the world and are successful predators. "The fact that they are from the Late Jurassic makes these eggs the oldest crocodilian eggs known so far," said João Russo of Universidade Nova de Lisboa, Portugal. "This new discovery from Portugal extends the knowledge of this type of egg by approximately 40 million years."
3-9-17 How to super-size your memory, according to science
How to super-size your memory, according to science
You can super size your memory to make it more like that of a world champion, according to scientists. Scans reveal that while memory champions' brains are nothing special in terms of anatomy, they do show changes in brain connectivity. What's more, neuroscientists were able to train people with ordinary memory skills to emulate the masters. The learners could remember lists of names at a time and showed similar brain connectivity patterns. "A good memory is something you could learn and you could train (for)," said lead researcher, Dr Martin Dresler, of Radboud University Medical Centre in Nijmegen, The Netherlands. "And if you use these strategic mnemonic training memory strategies you can really considerably increase your memory, even if you have a very bad memory at the start." The findings , based on brain scans of 23 world memory champions, are published in the scientific journal, Neuron.
3-9-17 New insight into secret lives of Neanderthals
New insight into secret lives of Neanderthals
Neanderthals dosed themselves with painkillers and possibly penicillin, according to a study of their teeth. One sick Neanderthal chewed the bark of the poplar tree, which contains a chemical related to aspirin. He may also have been using penicillin, long before antibiotics were developed. The evidence comes from ancient DNA found in the dental tartar of Neanderthals living about 40,000 years ago in central Europe. Microbes and food stuck to the teeth of the ancient hominins gives scientists a window into the past. By sequencing DNA preserved in dental tartar, international researchers have found out new details of the diet, lifestyle and health of our closest extinct relatives. "Their behaviour and their diet looks a lot more sophisticated and a lot more like us in many ways," said Prof Alan Cooper, director of the University of Adelaide's Australian Centre for Ancient DNA. "You know, we've got a guy self-medicating either because he's got a dental abscess, which was bad, or a nasty gastrointestinal parasite, which was also bad, either way he wasn't a happy guy. "And, here he is eating aspirin and we're finding penicillin mould in him."
3-8-17 How to train your brain to be like a memory champion’s
How to train your brain to be like a memory champion’s
Volunteers who practised a technique favoured by elite mnemonists more than doubled their memory capacity – and their brains became more champion-like. Becoming a memory champion is easier than you think. The techniques mnemonists use to memorise hundreds of words or digits in minutes can be learned by anyone, a study suggests. After just six weeks’ training, participants more than doubled their performance in a memory test, and scans showed their brains were functioning more like those of competitive memorisers. Memory athletes compete to memorise huge strings of information, such as decks of cards or digits of pi. To investigate what enables them to do it, Martin Dresler at Radboud University Medical Centre in the Netherlands recruited 23 of the world’s top 50 memory athletes. He was helped by a postdoc, Boris Konrad, who has competed in memory championships himself. All the athletes had their brains scanned to look for features that might mark them out from the general population. To Dresler’s surprise, there seemed to be nothing special about their brain structure: no particular areas or connections that looked larger or different. However, functional MRI scans revealed that the patterns of activity in brain areas related to memory and visuospatial processing looked different when the experts weren’t performing any particular tasks.
3-8-17 Neanderthals may have medicated with penicillin and painkillers
Neanderthals may have medicated with penicillin and painkillers
DNA extracted from dental plaque suggests our extinct cousins could self-medicate and they shared mouth bacteria with humans, perhaps transmitted by kissing. What a difference 1000 kilometres make. Neanderthals living in prehistoric Belgium enjoyed their meat – but the Neanderthals who lived in what is now northern Spain seem to have survived on an almost exclusively vegetarian diet. This is according to new DNA analysis that also suggests sick Neanderthals could self-medicate with naturally occurring painkillers and antibiotics, and that they shared mouth microbiomes with humans – perhaps exchanged by kissing. Neanderthals didn’t clean their teeth particularly well – which is lucky for scientific investigators. Over time, plaque built up into a hard substance called dental calculus, which still clings to the ancient teeth even after tens of thousands of years. Researchers have already identified tiny food fragments in ancient dental calculus to get an insight into the diets of prehistoric hominins. Now Laura Weyrich at the University of Adelaide, Australia, and her colleagues have shown that dental calculus also carries ancient DNA that can reveal both what Neanderthals ate and which bacteria lived in their mouths. The team focused on three Neanderthals – two 48,000-year-old specimens from a site called El Sidrón in Spain and a 39,000-year-old specimen from a site called Spy in Belgium. The results suggested that the Spy Neanderthal often dined on woolly rhinoceros, sheep and mushrooms – but no plants. The El Sidrón Neanderthals ate more meagre fare: moss, bark and mushrooms – and, apparently, no meat.
3-8-17 Ancient dental plaque tells tales of Neandertal diet and disease
Ancient dental plaque tells tales of Neandertal diet and disease
Calcified dental plaque from the upper jaw of a young Neandertal male from El Sidron cave in Spain reveals insights into his vegetarian diet and dental health problems. Dental plaque preserved in fossilized teeth confirms that Neandertals were flexible eaters and may have self-medicated with an ancient equivalent of aspirin. DNA recovered from calcified plaque on teeth from four Neandertal individuals suggest that those from the grasslands around Beligum’s Spy cave ate woolly rhinoceros and wild sheep, while their counterparts from the forested El Sidron cave in Spain consumed a menu of moss, mushrooms and pine nuts. The evidence bolsters an argument that Neandertals’ diets spanned the spectrum of carnivory and herbivory based on the resources available to them, Laura Weyrich, a microbiologist at the University of Adelaide in Australia, and her colleagues report March 8 in Nature.
3-8-17 Ancient nomadic herders beat a path to the Silk Road
Ancient nomadic herders beat a path to the Silk Road
Highland herders in Asia forged high-altitude travel routes that became part of an ancient trade network known as the Silk Road, a new study concludes. This Silk Road caravanserai, or inn, near a simulated herder route sits at about 3,500 meters above sea level in Kyrgyzstan, near the Chinese border. Nomadic herders took the ancient Silk Road to new heights. Starting 4,000 years ago or more, Central Asian herders routinely migrated from highland pastures in summer to lowland areas in winter (SN: 5/3/14, p. 15). Over roughly the next 2,000 years, those routes through mountainous regions eventually became a key part of the Silk Road, an ancient trade and travel network stretching from China to Europe, says a team led by anthropologist Michael Frachetti of Washington University in St. Louis. This finding underscores the important contribution of nomadic herders, interacting with lowland farmers and early city dwellers, to the Silk Road and overland trade, the researchers conclude in the March 9 Nature. Extensive Silk Road pathways ran across Asia by around 2,200 years ago. Merchants, pilgrims, monks and soldiers, as well as nomads, traveled these routes (SN Online: 7/29/16).
3-8-17 Good hydrations: Do I need eight glasses of water a day?
Good hydrations: Do I need eight glasses of water a day?
Tap or bottled? Still or sparkling? Eight glasses a day? There are a lot of fibs mixed with the cold, refreshing facts about life’s most essential nutrient. It’s not called Adam’s ale for nothing. Water was presumably what our early ancestors drank, to the exclusion of everything else. If you stopped drinking it now you would be dead within a week. It is the only nutrient whose absence is lethal in so short a time. But how much you should drink is surprisingly contentious. It is common to hear eight glasses a day – about 2 litres – even if you don’t feel thirsty. In 2002, physiologist Heinz Valtin of Dartmouth Medical School in New Hampshire tried to track down the source of this advice. The closest he came was a 1974 book that casually advised six to eight drinks a day – not just water but also soft drinks, coffee, tea, milk and even beer. As for its scientific validity, Valtin found none. As the Food and Nutrition Board of the US National Academies of Science, Engineering and Medicine advises: “The vast majority of healthy people adequately meet their daily hydration needs by letting thirst be their guide“. The only exception is some elderly people whose feedback mechanisms go awry, meaning they can become dehydrated without thirst. Generally, there is little to gain by doing more than just quenching your thirst. Water doesn’t remove toxins from the skin, visibly improve your complexion or cure constipation. There is some support for the idea that drinking cold water makes you burn calories, and water with a meal does reduce overall calorie intake, perhaps because it helps fill you up or displaces calories from sugary drinks. But the overall influence of water on weight is far from clear.
3-8-17 Good hydrations: Is fruit juice better than soda?
Good hydrations: Is fruit juice better than soda?
Fizzy pop is just candy in a can, and diet alternatives are full of nasties. Pure 100% fruit juice is best – or so we’re led to believe. Sugary drinks rot your teeth, and the more you drink, the more they will rot. Fizzy pop is generally assumed to be the worst. That is not because of dissolved CO2 – it is a myth that sparkling mineral water is any worse for your teeth than the plain variety – but because of the combination of sugar and common flavourings such as phosphoric acid. Their high sugar content means squashes and sodas deliver a huge calorie hit without filling you up: one standard can of a drink like cola provides more than the recommended daily amount of “free” or added sugar. That piles in excess energy that we store as fat. Those who regularly imbibe sugary drinks are more likely to be overweight, regardless of income or ethnicity, and consuming a can of sweetened fizz or the equivalent a day increases the risk of type 2 diabetes by a quarter. Overall, this form of liquid sustenance has little to recommend it.
3-8-17 Good hydrations: Does milk make healthy brains and bones?
Good hydrations: Does milk make healthy brains and bones?
It’s a richly nutritious mixture of sugars, proteins, vitamins, minerals and fat. Babies need it – but for the rest of us the evidence is semi-skimmed at best. Milk is a richly nutritious mixture of water, proteins, minerals, vitamins, sugars, saturated fat and cholesterol. All mammals make it, but humans are the only ones to drink it beyond their early years. Should we? Breast milk – or synthetic versions of it – provides the “perfect balance of nutrients” for babies in their first year, says Andy Bernstein, a paediatrician at Northwestern University in Evanston, Illinois. After that, full-fat cow’s milk is recommended as a good source of fat for brain development, dropping to 1 or 2 per cent fat milk from age 2. But although programmes in the US and UK that gave milk to children in schools were associated with huge health benefits, it is not clear why. “We don’t know if there is something specific or special about milk, or if it is just the fact that these children are getting more calories, protein, nutrients in general,” says Andrea Wiley of the University of Indiana at Bloomington. A recent study of children in Kenya found that supplemental milk helped those with stunted growth catch up in height, but provided no benefits over a non-milk nutritional supplement for children developing normally. For adults, the benefits seem even more dubious. There is no conclusive evidence, for example, that getting extra calcium from milk is vital for maintaining healthy bones or avoiding fractures. Other foods besides milk – “beans and greens”, largely – are also rich in calcium, and most researchers now argue that a generally healthy diet and plenty of weight-bearing physical activity is what keeps bones healthy.
3-8-17 Good hydrations: Is tea or coffee better for you?
Good hydrations: Is tea or coffee better for you?
Coffee has the edge when it comes to stimulation, but tea’s all-round health benefits make it a winner – except there’s another story brewing. Coffee is no good for you – that’s the received wisdom, at least. It is full of caffeine that’s addictive and can make you bounce off the walls, give you headaches and disrupt sleep. Excessive consumption has been linked to heart disease and cancer. And although coffee increases alertness and focus, the effects are short-lived. Users quickly become tolerant: people who regularly drink coffee are no more alert on average than those who don’t. For regulars, the morning brew merely reverses the fatiguing effects of caffeine withdrawal, bringing them back to a baseline level of alertness. Sounds like one to avoid, then. But Kirsty Pourshahidi of the Northern Ireland Centre for Food and Health in Coleraine, UK, thinks that’s overbrewed. “Having looked into it, I don’t feel so bad having three or four cups of coffee a day,” she says.
3-8-17 Good hydrations: Are health drinks healthy?
Good hydrations: Are health drinks healthy?
Coconut water, wheatgrass smoothies, vinegar, beetroot juice, even urine – the list of trendy cure-all potions is growing. These are the ones that work. Being potassium-rich, coconut water supposedly enhances your ability to absorb water during prolonged exercise. If that were true, though, it would also increase your risk of overhydration. In fact, studies show it is no better or worse at hydrating than a much cheaper beverage: water. As yet there is no scientific verdict on more recently trending hyper-hydrating waters – including watermelon water, as endorsed by singer Beyoncé, and birch sap water, as endorsed by Nordic folklore.
- Coconut water
- Beetroot juice
- Wheatgrass smoothies
3-8-17 Invasive snakes threaten forests on Pacific island of Guam
Invasive snakes threaten forests on Pacific island of Guam
Brown tree snakes, which have wreaked havoc among bird populations on the Pacific island of Guam, may also be damaging the forests. Scientists say that the slithery invaders' dietary habits are preventing the spread of tree seeds by birds. Researchers say the growth of new trees on the island may have fallen by up to 92%. These losses may have grave, long-term consequences for forests and other species. These dull brown creatures with their bright yellow underbellies are believed to have arrived in the western Pacific island by cargo ship after World War II. Although only 50km long and 10km wide, Guam is now home to around two million of these nocturnal predators. The snakes have thrived on a diet of local bird species. By the 1980s they had wiped out 10 of the 12 forest bird species native to Guam. "It's a really eerie feeling to spend a day by yourself in the jungle on Guam," said study lead author Prof Haldre Rogers, from Iowa State University. "When you're on Saipan, there's this constant bird chatter, and you get visited by different birds. On Guam, it's silent." As well as the silent destruction of the bird population, researchers are now concerned that the tree snake's rise will significantly impact the island's forests. Prof Rogers and colleagues found that about 70% of the trees on Guam produce small fruit. Normally birds eat the fruit and distribute the seeds in their droppings. (Webmaster's comment: Evolution at work. Man introduces snakes to island. The snakes kill the birds. The birds don't pollinate the trees. The trees die.)
3-8-17 Sociable woodpeckers that cooperate have evolved smaller brains
Sociable woodpeckers that cooperate have evolved smaller brains
It’s long been thought that living in a group leads to bigger brains – including in humans. But a surprising finding in woodpeckers shows this isn’t always the case. In primates such as humans, living in cooperative societies usually means having bigger brains — with brainpower needed to navigate complex social situations. But surprisingly, in birds the opposite may be true. Group-living woodpecker species have been found to have smaller brains than solitary ones. Cooperative societies might in fact enable birds to jettison all that brainpower otherwise needed on their own to constantly out-think, outfox and outcompete wily rivals, say researchers. Socialism in birds may therefore mean the individuals can afford to get dumber. The results are based on a comparison of brain sizes in 61 woodpecker species. The eight group-living species identified typically had brains that were roughly 30 per cent smaller than solitary and pair-living ones. “It’s a pretty big effect,” says lead researcher Richard Byrne at the University of St Andrews in the UK. Byrne’s explanation is that a solitary life is more taxing on the woodpecker brain than for those in cooperative groups, in which a kind of group-wide “social brain” takes the strain off individuals when a challenge arises.
3-8-17 Nudging people to make good choices can backfire
Nudging people to make good choices can backfire
Choice architects like to prod us to save for retirement and eat healthier. Nudging people to make good choices, about their retirement plans, charitable giving or even preventive health care, does not always go as planned. Nudges are a growth industry. Inspired by a popular line of psychological research and introduced in a best-selling book a decade ago, these inexpensive behavior changers are currently on a roll. Policy makers throughout the world, guided by behavioral scientists, are devising ways to steer people toward decisions deemed to be in their best interests. These simple interventions don’t force, teach or openly encourage anyone to do anything. Instead, they nudge, exploiting for good — at least from the policy makers’ perspective — mental tendencies that can sometimes lead us astray. But new research suggests that low-cost nudges aimed at helping the masses have drawbacks. Even simple interventions that work at first can lead to unintended complications, creating headaches for nudgers and nudgees alike.
3-7-17 Best anti-ageing exercise is high intensity interval training
Best anti-ageing exercise is high intensity interval training
Exercise is the best anti-ageing pill, but which routine is most effective? A study reveals that HIIT is better than weight training at rejuvenating cells. HIIT it! We’re often told that exercise is the best medicine, and it now seems that regular high intensity interval training (HIIT), in particular, is great for reversing the declining ability of our cells to generate energy. HIIT involves short bursts of very intense activity, interspersed with recovery periods of lower-intensity exercise. Sreekumaran Nair at the Mayo Clinic in Rochester, Minnesota, and his colleagues assigned groups of people aged between 18 and 30 and between 65 and 80 to three months of interval training, weight training or a combination of the two. Muscle biopsies were taken before and afterwards to measure the impact of these regimes on their cells. Interval training boosted the ability of the mitochondria within cells to generate energy by 69 per cent in older volunteers, and by 49 per cent in the younger group. Mitochondrial activity declines with age, which may aggravate fatigue and reduce the size and ability of muscles to burn excess blood sugar – a risk factor for diabetes. But this decline was halted and even reversed in the older interval-training group. “After three months of interval training, everything converged towards what we saw in young people,” says Nair.
3-7-17 Fleets of drones could pollinate future crops
Fleets of drones could pollinate future crops
A forgotten, failed experiment sent a robot airborne. Flitting drones might one day help bees and other insects pollinate flowers and crops, according to chemist Eijiro Miyako. Eijiro Miyako gets emotional about the decline of honeybees. “We need pollination,” he says. “If that system is collapsed, it’s terrible.” Insects, especially bees, help pollinate both food crops and wild plants. But pollinators are declining worldwide due to habitat loss, disease and exposure to pesticides, among other factors (SN: 1/23/16, p. 16). Miyako, a chemist at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan, became passionate about the loss of pollinators after watching a TV documentary. He remembers thinking: “I need to create something to solve this problem.” His answer was in an 8-year-old jar in his lab. In 2007, he had tried to make a gel that conducts electricity, but it was “a complete failure,” he says. So he poured the liquid into a jar, put it in a drawer and forgot about it. Cleaning out his lab in 2015, he accidentally dropped and broke the jar. Surprisingly, the gel was still sticky and picked up dust from the floor. Miyako realized that the gel’s ability to capture the tiny particles was similar to how honeybee body hairs trap pollen. His thoughts jumped to artificial pollination. (Webmaster's comment: What choice do we have? We killed off the bees!)
3-7-17 Raindrops make soil bacteria take off and fly through air
Raindrops make soil bacteria take off and fly through air
When raindrops hit the ground, they throw microbes into the air in aerosols – with possible implications for the climate, agriculture and diseases. When water falls to the ground, bacteria take to the skies. High-speed camera footage has revealed how raindrops can disperse microbes from the soil into the air in tiny water droplets, possibly allowing them to travel long distances. Bacteria and other microorganisms are abundant in the atmosphere, affecting the weather and helping to spread diseases. We knew at least two ways they could get there: wind can lift them into the air from dry soil, and bursting bubbles can expel them from the ocean. Splashing raindrops is now a third. Cullen Buie and his colleagues at Massachusetts Institute of Technology used high-speed cameras to film drops landing on six types of soil. The soil contained three species of bacteria stained with a fluorescent green dye that allowed them to be seen. Images from the experiment show bacteria inside fine droplets, or aerosols, thrown up by the simulated raindrops.
3-7-17 Why we sleepwalk
Why we sleepwalk
Last night, most of us went to the safety and comfort of our beds before drifting off to a night's sleep. For some, this was the last conscious action before an episode of sleepwalking. Recent research from Stanford University shows that up to 4 percent of adults might have had such an experience. In fact, sleepwalking is on the rise, in part due to increased use of pharmacologically based sleep aids — notably Ambien. Often, the episodes are harmless. Take for example, Lee Hadwin, a Londoner whose professional artistic talent seems to be present and activated only while he sleeps. Why do some enter into such a potentially harmful state during sleep? One answer comes from studies suggesting that "sleepwalking" might not be an appropriate term for what is going on; rather, primitive brain regions involved in emotional response (in the limbic system) and complex motor activity (within the cortex) remain in "active" states that are difficult to distinguish from wakefulness. Such activity is characterized by "alpha wave" patterns detected during electroencephalogram (EEG) recordings. At the same time, regions in the frontal cortex and hippocampus that control rationality and memory remain essentially dormant and unable to carry out their typical functions, manifesting a "delta wave" pattern seen during classic sleep. It's as though sleepwalking results when the brain doesn't completely transition from sleep to wakefulness — it's essentially stuck in a sleep-wake limbo.
3-7-17 Older people are just as good at judging music as younger adults
Older people are just as good at judging music as younger adults
Many of the brain's executive functions decline as we age, but older people can spot a lack of harmony as adeptly as young people. It may feel as if many of our mental abilities decline with age, but here’s one that sticks – our ability to sense when music sounds wrong. When you listen to music, your brain tries to predict the next note, regardless of whether you have had any musical training. This active guesswork is part of what makes music so engaging. To see if this changes over our lifetime, Joydeep Bhattacharya at Goldsmiths, University of London, and his team measured the brainwaves of 14 adults under the age of 33, and 15 people aged 62 and over, as they listened to music. All participants heard 100 short pieces composed specially for the study. Each piece ended either in a standard melodic progression used in Western music, or in an unorthodox pattern. Many of our brain’s executive functions become impaired as we get older, but this didn’t turn out to be the case for sensing a lack of harmony. Both groups detected the unexpected endings equally well. The older people employed a wider region of the brain, though. “Recruiting a broader region perhaps compensates for the expected impairment that often takes place with age,” says Bhattacharya.
3-6-17 Brain’s inability to see that something is safe causes OCD
Brain’s inability to see that something is safe causes OCD
People with obsessive compulsive disorder aren’t more afraid of things than other people, they struggle to learn that mildly risky things are generally safe. The repeated thoughts and urges of obsessive compulsive disorder (OCD) may be caused by an inability to learn to distinguish between safe and risky situations. A brain-scanning study has found that the part of the brain that sends out safety signals seems to be less active in people with the condition. People with OCD feel they have to carry out certain actions, such as washing their hands again and again, checking the oven has been turned off, or repeatedly going over religious thoughts. Those worst affected may spend hours every day on these compulsive “rituals”. To find out more about why this happens, Naomi Fineberg of Hertfordshire Partnership University NHS Foundation Trust in the UK and her team trained 78 people to fear a picture of an angry face. The team did it by sometimes giving the volunteers an electric shock to the wrist when they saw the picture while they were lying in an fMRI brain scanner. About half the group had OCD. The team then tried to “detrain” the volunteers, by showing them the same picture many times, but without any shocks.
3-6-17 Prize for cracking brain's 'feel good' system
Prize for cracking brain's 'feel good' system
The UK-based winners cracked the brain's "reward centre." It influences your happiness, pleasure or motivation to do something. But the system can go wrong turning people into addicts. Three UK-based scientists have won a prestigious prize worth 1m euros for studying the brain's reward centre. Their work helps understand our drive to shop, eat or even land on the moon. Reward is necessary for keeping us alive, but it can also spiral out of control leading to gambling and drug addiction. Wolfram Schultz, Peter Dayan and Ray Dolan said winning The Brain Prize - the biggest in the field of neuroscience - was a "great honour". Prof Schultz is planning a holiday with the family, but his co-winners are still trying to figure out how to spend their prize money from Denmark's Lundbeck Foundation.
3-6-17 Brain’s reward system earns researchers €1 million prize
Brain’s reward system earns researchers €1 million prize
The dopamine reward system plays a role in everything from drug addiction to psychopathic behaviour, and is important for teaching us to make good decisions. Unpicking the secrets of the brain’s reward system has earned three neuroscientists a reward of their own. Wolfram Schultz, Peter Dayan, and Ray Dolan have today been awarded the €1 million Brain Prize by Denmark’s Lundbeck Foundation. The prize recognises researchers who have made vital contributions to understanding how our brains work. Together, their research has revealed how reward systems in the brain that involve the signalling chemical dopamine influence our behaviour and survival, playing important roles in decision-making, gambling, drug addiction, psychopathic tendencies, and schizophrenia. “This is the biological process that makes us want to buy a bigger car or house, or be promoted at work,” says Wolfram Schultz, at the University of Cambridge. Schultz discovered through experiments on monkeys 30 years ago that when the animals receive a reward, specialised brain cells become more active and make dopamine. Subsequently, he showed that this could be triggered through learned cues, even without a reward. Peter Dayan, at University College London, took Schultz’s work further by showing how we constantly update our goals through a dopamine-driven phenomenon called “reward prediction error”. Dayan showed how our future behaviour is dictated by daily feedback on whether anticipated rewards and pleasures either fail to materialise or are more generous than anticipated.
3-6-17 Anesthesia for youngsters is a tricky calculation
Anesthesia for youngsters is a tricky calculation
Short, one-time bouts of anesthesia probably don’t cause lasting harm to children’s brains, several studies suggest. But scientists have a lot to learn about anesthetics’ lasting effects, particularly in the youngest patients. If your young child is facing ear tubes, an MRI or even extensive dental work, you’ve probably got a lot of concerns. One of them may be about whether the drugs used to render your child briefly unconscious can permanently harm his brain. Here’s the frustrating answer: No one knows. “It’s a tough conundrum for parents of kids who need procedures,” says pediatric anesthesiologist Mary Ellen McCann, a pediatric anesthesiologist at Boston Children’s Hospital. “Everything has risks and benefits,” but in this case, the decision to go ahead with surgery is made more difficult by an incomplete understanding of anesthesia’s risks for babies and young children. Some studies suggest that single, short exposures to anesthesia aren’t dangerous. Still, scientists and doctors say that we desperately need more data before we really understand what anesthesia does to developing brains.
3-6-17 Identity of ‘Tully monster’ still a mystery
Identity of ‘Tully monster’ still a mystery
New study debunks idea that oddball aquatic creature was a vertebrate. The Tully monster was an aquatic creature that lived about 300 million years ago. Its strange features have made it difficult to classify, but new research suggests that it wasn’t a vertebrate. The true nature of the “Tully monster” may once again be a mystery. Just last year, some researchers declared that the extinct aquatic animal was a vertebrate, possibly a relative of today’s lampreys. Not so fast, says vertebrate paleontologist Lauren Sallan. Like a mismatched puzzle, the Tully monster lacks some vertebrate pieces and has others that are the wrong shape, Sallan and colleagues report in the March issue of Palaeontology. Tullimonstrum gregarium didn’t get its monstrous name because of its size. Only about a foot long, the oddball creature, which lived about 300 million years ago, sported wide-set eyes like a hammerhead shark and a pincerlike mouth at the end of a long trunk. In the past, it’s been lumped in with everything from sea slugs to arthropods.
3-3-17 How personalities evolve
How personalities evolve
Feel like you’re not the person you used to be? You’re probably right. The longest-running personality study ever conducted reveals that people change so dramatically as the years go by that they often bear little resemblance to their younger selves. In 1950, researchers asked teachers to assess specific personality traits of 1,208 14-year-old students, including their self-confidence, originality, perseverance, conscientiousness, stability of moods, and desire to excel. In 2012, 174 of the original students agreed to participate in a second evaluation. Now in their 70s, they completed cognitive tests and answered detailed questionnaires, rating themselves on the same characteristics. They also had a close friend or relative evaluate their personality. After comparing the results, the researchers found no correlation between the participants’ current personality and who they were as teenagers, HuffingtonPost.com reports. “Personality changes only gradually throughout life, but by older age it may be quite different from personality in childhood,” the authors say, noting that genetic and environmental factors likely influence how personalities evolve over time.
3-3-17 The science of why heartbreak is so painful
The science of why heartbreak is so painful
A few years ago, Yeshiva University neuroscientist Lucy Brown and her research team distributed flyers across several campuses in the New York area to recruit participants for a brain-imaging study. The flyers had one sentence highlighted: "Have you just been rejected in love but can't let go?" Soon enough, Brown recalls, she had college students — who were asked to bring a photo of their beloved with them — crying in the brain scanner. The brains of the forlorn study subjects looked a lot like drug addicts fiending for a fix. "In retrospect, it's not surprising that the same areas of the brain that were active in the brains of cocaine addicts were active in these people who were heartbroken looking at a picture of their former romantic partner," Brown tells Science of Us. "We crave the other person just as we crave nicotine or pain pills; you want to be near the other person, you're constantly thinking about them, we even do dangerous things sometimes to win them back — we don't eat or sleep." Indeed, in the 2010 paper that came from this tearful inquiry, all 15 of her crestfallen participants reported thinking about their beloved for over 85 percent of their waking hours, and all reported a yearning to rejoin in emotional union with their former partners. "Signs of lack of emotion control" happened for weeks or months after the initial breakup, the authors found, including "inappropriate phoning, writing or e-mailing, pleading for reconciliation, sobbing for hours, drinking too much, and/or making dramatic entrances and exits into the rejecter's home, place of work or social space to express anger, despair, or passionate love." (And there you have the shape of every romantic narrative.)
3-3-17 The risks of added testosterone
The risks of added testosterone
For years men of a certain age have turned to testosterone to boost energy and revive flagging libido. A new study, however, reveals the risks of this hormone replacement therapy may outweigh its benefits. In trials involving 788 men 65 or older with low testosterone levels, University of Pennsylvania researchers randomly assigned half the participants to apply daily testosterone gel; the rest received a placebo. After one year, testosterone users saw increased bone density and lower risk for anemia. But the hormone had no discernible effect on energy level, memory, or cognitive abilities; worse, men on testosterone had more plaque buildup in their coronary arteries—a risk factor for heart disease, BBC.com reports. The authors say larger long-term studies are needed, and treatment decisions should be made on an individual basis. “The message here is to select the correct patients who will benefit from testosterone therapy,” says endocrinologist Channa Jayasena, “but not treat it as a wonder drug.”
3-3-17 If you think the Amazon jungle is completely wild, think again
If you think the Amazon jungle is completely wild, think again
Fruit and nut tree species cultivated by ancient peoples still dominate parts of forest. A new study finds that 20 partly or fully domesticated tree species are far more common than wild tree species in some Amazonian forests. One of those species, the moriche palm (shown) bears an edible fruit with a hard covering. Welcome to the somewhat civilized jungle. Plant cultivation by native groups has shaped the landscape of at least part of South America’s Amazon forests for more than 8,000 years, researchers say. Of dozens of tree species partly or fully domesticated by ancient peoples, 20 kinds of fruit and nut trees still cover large chunks of Amazonian forests, say ecologist Carolina Levis of the National Institute for Amazonian Research in Manaus, Brazil, and colleagues. Numbers and variety of domesticated tree species increase on and around previously discovered Amazonian archaeological sites, the scientists report in the March 3 Science. Domesticated trees are “a surviving heritage of the Amazon’s past inhabitants,” Levis says. The new report, says archaeologist Peter Stahl of the University of Victoria in Canada, adds to previous evidence that “resourceful and highly developed indigenous cultures” intentionally altered some Amazonian forests.
3-3-17 Amazon forest 'shaped by pre-Columbian indigenous peoples'
Amazon forest 'shaped by pre-Columbian indigenous peoples'
Indigenous peoples who inhabited the Amazon before the arrival of European colonisers planted a vast number of trees, a new study argues. They played an important role in the current composition of the forest, says the study. Researchers found that species used for food or building materials were far more common near ancient settlements. "So the Amazon is not nearly as untouched as it may seem," said Dr Hans ter Steege in the Netherlands. Eighty-five species that produced Brazil nuts, cashew nuts, acai or rubber were also five times more likely to be dominant in mature forest than non-domesticated species. The scientists reached their conclusions by comparing data on tree composition from more than 1,000 locations in the Amazon with a map of archaeological sites.
3-3-17 DNA clues to why woolly mammoth died out
DNA clues to why woolly mammoth died out
The last woolly mammoths to walk the Earth were so wracked with genetic disease that they lost their sense of smell, shunned company, and had a strange shiny coat. That's the verdict of scientists who have analysed ancient DNA of the extinct animals for mutations. The studies suggest the last mammoths died out after their DNA became riddled with errors. The knowledge could inform conservation efforts for living animals. There are fewer than 100 Asiatic cheetahs left in the wild, while the remaining mountain gorilla population is estimated at about 300. The numbers are similar to those of the last woolly mammoths living on Wrangel Island in the Arctic Ocean around 4,000 years ago. Dr Rebekah Rogers of the University of California, Berkeley, who led the research, said the mammoths' genomes "were falling apart right before they went extinct". This, she said, was the first case of "genomic meltdown" in a single species. "You had this last refuge of mammoths after everything has gone extinct on the mainland," she added. "The mathematical theories that have been developed said that they should accumulate bad mutations because natural selection should become very inefficient." The researchers analysed genetic mutations found in the ancient DNA of a mammoth from 4,000 years ago. They used the DNA of a mammoth that lived about 45,000 years ago, when populations were much larger, as a comparison.
3-3-17 Ancient skulls give clues to China human history
Ancient skulls give clues to China human history
Two skulls found in China shed light on the ancient humans who inhabited the region before our own species arrived. We know that Europe and western Asia was dominated by the Neanderthals before Homo sapiens displaced them. But remains belonging to equivalent populations in East and Central Asia have been scarce. It's unclear if the finds are linked to the Denisovans, a mysterious human group known only from DNA analysis of a tooth and finger bone from Siberia. Prof Erik Trinkaus, one of the authors of a study on the remains in Science journal, said it was not possible to say at this stage whether the ancient people from Xuchang were connected to the Denisovans. "The issue here is the patterns of variation and the population dynamics of 'archaic' populations during the later part of the Pleistocene," Prof Trinkaus, from Washington University in St Louis, told BBC News. Modern humans (Homo sapiens) originated in Africa some 200,000 years ago before expanding out across Asia, Europe, Oceania and the Americas after 60,000 years ago. As they spread across the world, they displaced the existing populations they encountered, such as the Neanderthals and Denisovans - but some limited interbreeding occurred. The partial skulls from China are between 105,000 and 125,000 years old and lack faces. But they show clear similarities to and differences from their Neanderthal contemporaries in the west.
3-2-17 Certain birth defects are on the rise since Zika arrived in the U.S.
Certain birth defects are on the rise since Zika arrived in the U.S.
Zika-infected mothers are 20 times more likely to have babies with certain birth defects. Zika infection during pregnancy substantially raises the risk that the baby will have certain birth defects, such as microcephaly and other brain deformations. A new CDC study quantifies that impact in the United States. Certain birth defects were 20 times more prevalent in babies born to Zika virus–infected mothers in the U.S. in 2016 than they were before the virus cropped up in the United States, a CDC study suggests. The finding strengthens the evidence that a mother’s Zika infection during pregnancy raises her baby’s risk of microcephaly and other brain malformations. The study, published March 3 in the CDC’s Morbidity and Mortality Weekly Report, examined data collected through birth defect surveillance programs in Massachusetts; North Carolina; and Atlanta, Georgia, in 2013 and 2014. In that timeframe — before Zika appeared in the United States — microcephaly, brain abnormalities or another Zika-associated birth defect appeared in just 3 out of every 1,000 live births. But from January to September 2016, 26 babies out of 442 born to mothers with suspected Zika virus infection during pregnancy showed these defects, according to data from the U.S. Zika Pregnancy Registry. That’s an incidence of nearly 60 per 1,000 pregnancies carried by women with Zika, far higher than the pre-Zika level.
3-2-17 Artificial embryo grown in a dish from two types of stem cells
Artificial embryo grown in a dish from two types of stem cells
For the first time, researchers have made something resembling a mouse embryo without using an egg cell, allowing them to probe the early steps of development. Artificial mouse embryos grown from stem cells in a dish could help unlock secrets of early development and infertility that have until now evaded us. Magdalena Zernicka-Goetz at the University of Cambridge and her team made the embryos using embryonic stem cells, the type of cells found in embryos that can mature into any type of tissue in the body. The trick was to grow these alongside trophoblast stem cells, which normally produce the placenta. By growing these two types of cell separately and then combining them in a special gel matrix, the two mixed and started to develop together. After around four-and-a-half days, the embryos resembled normal mouse embryos that were about to start differentiating into different body tissues and organs. “They are very similar to natural mouse embryos,” says Zernicka-Goetz. “We put the two types of stem cells together – which has never been done before – to allow them to speak to each other. We saw that the cells could self-organise themselves without our help.” This is the first time something resembling an embryo has been made from stem cells, without using an egg in some way. Techniques such as cloning, as done for Dolly the sheep and other animals, bypass the need for sperm, but still require an egg cell.
3-2-17 Humans help cook up mineral bounty
Humans help cook up mineral bounty
Scientists have identified 208 new minerals that owe their existence wholly or in part to humans. Many in the list have been found down old mine tunnels or on slag heaps where water and even fire have had the opportunity to work up novel compounds. It is another example, the researchers argue, of our pervasive influence on the planet. New minerals and mineral-like compounds are now being formed faster than at anytime in Earth's history, they say. "These 200 minerals are roughly 4% of the total known minerals, but they all occurred in the last couple of thousand years, most in the last couple of hundred years," explained Robert Hazen from the Carnegie Institution for Science in Washington DC. "That's an incredible rapid spike in the rise of mineral species unmatched in the history of our planet," he told BBC News. The only period that bears comparison is the time when oxygen became abundant over the surface of the Earth just over two billion years ago. But that event would have played out over millions of years.
3-2-17 Origin of photosynthesis may go further back than estimates from 50 years ago
Origin of photosynthesis may go further back than estimates from 50 years ago
From deep in the gold mines of South Africa’s Orange Free State has come evidence that there was some form of biologic activity on Earth at least 2.15 billion years ago. Polymerized hydrocarbon “chemo-fossils” found in the gold ores … [probably] were originally part of a rich bacterial and algal life in the Witwatersrand basin. Since the rock layers from which they come have been dated to about 2.15 billion years ago, it seems likely that photosynthesis existed on Earth before then. — Science News, March 18, 1967. Scientists still debate when early photosynthesizing organisms called cyanobacteria began pumping oxygen into Earth’s atmosphere. Recent evidence suggests the microbes existed some 3.2 billion years ago (SN Online: 9/8/15), even though a larger oxygen surge didn’t happen until about 2.4 billion years ago (SN: 3/4/17 p. 9). Those tiny bacteria left an outsized impact on our planet, releasing extra oxygen into the atmosphere that paved the way for complex multicellular life like plants and animals.
3-1-17 Gene therapy ‘cures’ boy of blood disease that affects millions
Gene therapy ‘cures’ boy of blood disease that affects millions
So far, gene therapy has only treated rare disorders. Now, for the first time, it has been used to treat a boy with sickle cell disease, a common genetic disease. “All the blood tests we performed show that the teenager has been cured of sickle cell disease” A TEENAGE boy with an inherited disease that affects millions worldwide seems to have been cured using gene therapy. The treatment appears to have stopped the painful symptoms of sickle cell disease, demonstrating the potential for gene therapy to treat common genetic diseases. The idea of gene therapy – using strands of DNA to compensate for a person’s malfunctioning genes – is almost three decades old. However, the approach has so far mostly been used to treat very rare diseases (see “Long road to success“). In contrast, sickle cell disease affects 100,000 people in the US alone. If the treatment proves successful in larger trials, it could bring gene therapy into widespread use. “It could be a game changer,” says Deborah Gill at the University of Oxford. “The fact the team has a patient with real clinical benefit, and biological markers to prove it, is a very big deal.”
3-1-17 Autoimmune disorders linked to an increased risk of dementia
Autoimmune disorders linked to an increased risk of dementia
People with conditions like multiple sclerosis and psoriasis are more likely to develop dementia, and cardiovascular problems could be to blame. People who have autoimmune disorders may be 20 per cent more likely to develop dementia. That’s according to an analysis of 1.8 million hospital cases in England. Based on data collected between 1999 and 2012, the study’s findings add to mounting evidence that chronic inflammation – a common feature of many autoimmune disorders – may be a trigger of dementia and Alzheimer’s disease. Previous studies have found that if infections or chronic inflammatory diseases – including diabetes – have pushed a person’s immune system into overdrive, this can lead to immune cells attacking healthy brain tissue. According to the analysis, people with multiple sclerosis are among those with autoimmune disorders who are most likely to develop dementia. This finding isn’t very surprising, as the disorder is caused by the immune system attacking the central nervous system. The study, led by Michael Goldacre at the University of Oxford, found that people with the condition have double the risk of developing dementia. But other autoimmune disorders were also associated with rises in dementia risk. The skin condition psoriasis was linked to a 29 per cent increase, while the risk of developing dementia was 46 per cent higher in people who have lupus erythematosus, a disorder that involves rashes and fatigue.
3-1-17 Colorectal cancer is on the rise among younger adults
Colorectal cancer is on the rise among younger adults
Unhealthy lifestyle linked to increase in tumor incidence, death rates. For decades, colorectal cancer rates have been falling, but a new report finds an uptick in the rates among U.S. adults under 50. In recent years, rates of colorectal cancer cases and deaths in the United States rose among young and middle-aged adults, an American Cancer Society study of colorectal cancer trends between 2000 and 2014 finds. That increase came even as rates of colon and rectal tumors and deaths dropped in people 50 and older, researchers report online March 1 in CA: A Cancer Journal for Clinicians. Overall, colorectal cancer and death rates are declining. This drop is attributed to decreases in smoking and red meat consumption, an increase in aspirin usage — which can calm inflammation that spurs tumor growth — and improvements in screening and treatment. Increased prevalence of obesity, unhealthy diets and sedentary lifestyles contributed to the rise in colorectal cancer cases and deaths among adults younger than 50, the researchers suspect.
3-1-17 Traces in rock may be the oldest evidence of life on Earth ever
Traces in rock may be the oldest evidence of life on Earth ever
Rocks that could be just 200 million years younger than Earth carry structures and signatures reminiscent of microbial activity, but some dispute that view. Are we closing in on life’s cradle? What is claimed to be the oldest evidence of life on Earth yet found backs the idea that the first microbes originated around hydrothermal vents on the seafloor – but the work is already proving controversial. Explaining the origin of life is one of the biggest unclaimed prizes in biology, and one that many scientists – including Nobel prizewinners – are chasing. The only thing we know for certain is that life must have popped into existence sometime between Earth’s formation 4.5 billion years ago and the appearance of the first undisputed fossils, about 3.4 billion years ago. Most origin-of-life researchers base their theories on biochemical principles. But to seek direct evidence of life’s emergence, they must visit some of Earth’s last remaining wildernesses, including parts of Greenland, northern Canada and Antarctica. By chance these are the only places where Earth’s oldest rocks – and potentially fossils – can still be found. Matthew Dodd at University College London and his colleagues have just finished analysing rocks collected from a region called the Nuvvuagittuq belt, in northern Quebec, Canada. The rocks here, on the coast of Hudson Bay, are at least 3.75 billion years old, and some geologists argue they are about 4.29 billion years old, which would mean they are just slightly younger than the planet itself.
3-1-17 Oldest microfossils suggest life thrived on Earth about 4 billion years ago
Oldest microfossils suggest life thrived on Earth about 4 billion years ago
Ancient microbes were spewed from deep-sea hydrothermal vents, study claims. In rocks left over from ancient hydrothermal vents, these microscopic tubes of hematite, an ore of iron, may be remnants of early microbes. Tiny, iron-rich fossils exhumed from the depths of an ancient ocean could reveal the cradle of life. These micrometer-scale structures are probably remnants of microorganisms that once lived amidst ancient hydrothermal vents, researchers suggest March 1 in Nature. “In a nutshell, what we’ve found are the oldest microfossils on Earth,” says study coauthor Matthew Dodd, a biogeochemist at University College London. The rocks that hold the fossils came from Quebec and date to somewhere between 4.28 billion and 3.77 billion years old — when Earth was still a baby. The next oldest microfossils reported are just under 3.5 billion years old, though their validity has been debated (SN: 2/8/14, p.16).
3-1-17 Earliest evidence of life on Earth 'found'
Earliest evidence of life on Earth 'found'
Scientists have discovered what they say could be fossils of some of the earliest living organisms on Earth. They are represented by tiny filaments, knobs and tubes in Canadian rocks dated to be up to 4.28 billion years old. That is a time not long after the planet's formation and hundreds of millions of years before what is currently accepted as evidence for the most ancient life yet found on Earth. The researchers report their investigation in the journal Nature. As with all such claims about ancient life, the study is contentious. But the team believes it can answer any doubts. The scientists' putative microbes from Quebec are one-tenth the width of a human hair and contain significant quantities of haematite - a form of iron oxide or "rust". Matthew Dodd, who analysed the structures at University College London, UK, claimed the discovery would shed new light on the origins of life. "This discovery answers the biggest questions mankind has asked itself - which are: where do we come from and why we are here?
3-1-17 The opposite birds: What wiped out the ancient rulers of the sky
The opposite birds: What wiped out the ancient rulers of the sky
Millions of years ago, the skies were full of birds strangely different from the ones we know today. So how did modern birds come to rule the roost? JUAN CARLOS LEAL and José Bonaparte were lost in a thick, thorny acacia forest in north-west Argentina when Leal stumbled on the bones. The big ones turned out to be from a new long-necked dinosaur species. But the 60 small bones they found alongside were puzzling. They were far too small to be from dinosaurs. Intrigued, Bonaparte flew to London to show them to a fossil expert at the Natural History Museum. Cyril Walker immediately recognised them as a rare find – the remains of ancient birds. By this point in the 1970s, some palaeontologists suspected that all birds had evolved from flying dinosaurs, but the idea was not yet mainstream. Looking closely, Walker discovered that the fossil shoulders and feet had grown quite differently to those of modern birds. A key ball-and-socket joint in the shoulder was reversed. This was a whole new avian category, not just a new species. In a short paper published in 1981, he named the fossils Enantiornis leali: Leal’s opposite bird. Now we know that Enantiornis wasn’t an evolutionary oddity. Millions of years ago, the skies were full of such creatures. Then, some 65 million years ago, an asteroid hit Earth and opposite birds were relegated to the history books along with the vast majority of dinosaurs. The only survivors gave rise to every bird alive today.
3-1-17 Squid evolved in marine wars more than 100 million years ago
Squid evolved in marine wars more than 100 million years ago
Evolution of jawed vertebrates and bony fish created evolutionary pressure that boosted cephalopod diversification some 100 million years ago. An evolutionary war that raged beneath the sea more than 100 million years ago created the octopus and squid, new research has shown. Cephalopods – the tentacled creatures that include octopuses, squid and cuttlefish – possess some extraordinary traits such as instantaneous colour changing, ink squirting, jet propulsion and polarised vision. Octopuses are also known to be highly intelligent for invertebrates and display an ability to solve complex problems. Until now the origins of cephalopods, which evolved from ancient marine molluscs with shells, have been shrouded in mystery. The new research from scientists at the University of Bristol, in the UK, suggests that the octopus and its relatives developed their bizarre body plans and unusual abilities during a period of upheaval beneath the waves known as the Mesozoic Marine Revolution.
3-1-17 Rock solid evidence of Anthropocene seen in 208 minerals we made
Rock solid evidence of Anthropocene seen in 208 minerals we made
Human activities like mining and building have created hundreds of minerals and spread them all over the world, leaving a significant mark on the geological record. The evidence of humans changing the planet is solid as rock. A new catalogue of minerals counts 208 that result solely or primarily from human activity, says Robert Hazen of the Carnegie Institution for Science in the US, who led the study. Accounting for almost 4 per cent of the 5200 minerals formally recognised by the International Mineralogical Association, the contribution humans have made is significant. Most minerals came about 2 billion years ago during the Great Oxidation, when free oxygen produced by photosynthetic bacteria appeared in Earth’s atmosphere. At that time, minerals spiked from just over 2000 varieties to more than 4000. “After that, it really was a kind of plateau,” says Jan Zalasiewicz at the University of Leicester. “The next big jump is what humans have been doing, and particularly in the recent decades.” Most minerals are a result of life-led processes. Life created abundant atmospheric oxygen that allowed for oxidation and the formation of a swathe of metal-rich minerals, such as iron oxides. And hard-bodied marine organisms, for example, created thick deposits of carbonate minerals, such as aragonite, when they died and settled on the seabed. But the pace at which humans have added new minerals over the past few hundred years is quicker than the pace at which mineral diversity increased during the last jump thousands of years ago.
3-1-17 'Best ever' view of what a dinosaur really looked like
'Best ever' view of what a dinosaur really looked like
A dinosaur that lived 160 million years ago had drumstick-shaped legs much like living birds, according to palaeontologists. The feathered dinosaur also had bird-like arms similar to wings. Scientists used high-powered lasers to reveal invisible details of what the creature looked like. The research could give insights into the origins of flight, which is thought to have evolved more than 150 million years ago. Michael Pittman of the University of Hong Kong said the study was a landmark in our understanding of the origins of birds. "In this study, what we've done is we've used high-powered lasers to reveal unseen soft tissues preserved alongside the bones of a feathered dinosaur called Anchiornis," he said.
3-1-17 Early warning signs of heart attacks 'being missed'
Early warning signs of heart attacks 'being missed'
Early warning signs may have been missed in up to one in six people who died of a heart attack in English hospitals, a study suggests. All heart attack admissions and deaths between 2006 and 2010 were analysed. Imperial College London researchers found 16% of those who died had been admitted to hospital in the previous 28 days. Some had warning signs like chest pain. The British Heart Foundation has called the research "concerning". The study authors from the School of Public Health at Imperial College say more research is "urgently needed". (Webmaster's comment: Often a woman having pains is diagnosed as just having "female" problems. This is still going on after centuries.)
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