Evolution and Global Warming are facts, not theories!

Hand Evolution by Megan Godtland

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Microwave Earth by Megan Godtland

2019 Science Stats

116 Evolution News Articles
for January 2019
Click on the links below to get the full story from its source

Nature cares only that you reproduce and raise the kids.
After you've done that, get out of the way.

1-31-19 This bacteria-fighting protein also induces sleep
Infected fruit flies slept more and survived longer when levels of Nemuri surged. “Feed a cold, starve a fever,” or so the adage goes. But fruit fly experiments suggest that sleep may be a better remedy. A microbe-fighting protein helps control how much and how deeply fruit flies sleep, researchers report in the Feb. 1 Science. That’s evidence that sleep speeds recovery from illness, they conclude. “We finally have a very clear link between being sleepy and fighting an infection,” says Caltech sleep researcher Grigorios Oikonomou, who was not involved in the work. Such a link has been hinted at but never formally demonstrated, says Oikonomou, who coauthored a commentary on the study in the same issue of Science. Researchers in Amita Sehgal’s lab at the University of Pennsylvania’s Perelman School of Medicine made the discovery while searching for genes that control sleep. Her team looked for proteins that, when overproduced, would cause Drosophila melanogaster fruit flies to sleep more. After combing through more than 8,000 overproduced proteins, the researchers found just one that lulled flies to sleep. Flies with an overabundance of that protein, produced from the nemuri gene, took more naps during the day and slept longer and deeper at night. Strong bumps from a device called “the hammer” roused only about 18 percent of these Nemuri-overproducing flies in the middle of the night but jolted awake more than 94 percent of normal flies, Sehgal’s team discovered. Flies that lacked Nemuri were more easily awakened than normal flies when researchers flicked lights on and off or wafted an odor into the tubes where the fruit flies were sleeping.

1-31-19 Self-growing material could make muscles that become stronger with use
Do you even lift? A new material is the stuff of envy for muscleheads everywhere: it bulks up and self-strengthens without ever needing to hit the gym. Takahiro Matsuda and his colleagues at Hokkaido University in Japan have developed a “self-growing” hydrogel, which improves its size and strength after repeated mechanical force. They believe it could be used to make flexible exosuits, for people with skeletal injuries, which become stronger the more they are used. Hydrogels are soft, flexible materials that come in a wide variety of forms: they’re used in disposable nappies and adhesive wound dressings, comprise soft contact lenses, and can even be edible – jelly is one such example. They’re formed of networks of absorbent polymer chains, and are 90 per cent water. The team’s self-growing hydrogel was inspired by the process human muscles undergo in response to exercise. Strength training and other activities damage muscle fibres, triggering a regeneration process that involves the growth of new tissue. The self-growing material is composed of two intertwined networks of polymers – essentially chains of molecules: one strand is rigid, and the other soft and stretchable. When the rigid strands were broken by force – being stretched, for example – it triggered new chains and crosslinks to form, while the softer second network maintained the structure of the gel. Developing a substance that could grow or reconstruct itself like living tissues has previously proved elusive. The self-growing hydrogel is a step up from self-healing materials, which recover to their previous state after being damaged. It’s “one of the mechanically strongest and toughest hydrogels in the world”, says Matsuda.

1-31-19 Giant pandas may have only recently switched to eating mostly bamboo
The switch to a bamboo diet occurred some 5,000 years ago, not 2 million years ago as thought. When it comes to deciding what’s for breakfast, lunch or dinner, pandas have it easy: Bamboo, bamboo and more bamboo. But that wasn’t always the case. Although modern giant pandas (Ailuropoda melanoleuca) chow almost exclusively on bamboo in the mountain forests of central China, these bears’ diet was much broader not so long ago, researchers report online January 31 in Current Biology. Analyses using chemical signatures from bones and teeth of both ancient and modern pandas indicate the bears’ hyperdependence on bamboo could have developed as recently as about 5,000 years ago. That’s roughly 2 million years later than previously assumed from molecular and paleontological data. “It has been widely accepted that giant pandas have exclusively fed on bamboo for a long time, but our results show the opposite,” says Fuwen Wei, a wildlife ecologist at the Chinese Academy of Sciences’ Institute of Zoology in Beijing. “That made us excited.” Wei and his colleagues compared the relative abundance of isotopes — atoms of the same element but with a different number of neutrons in the nucleus — in modern and fossil animals, including pandas. Animal diets contain different amounts of naturally occurring “heavy” and “light” isotopes of carbon, oxygen and nitrogen that are then incorporated into bones, hair, nails and teeth. The ratio in which the isotopes occur in the body depends on the animal’s position in the food chain and the climate in which the animal lives. Carnivores, for example, have a higher abundance of the heavy nitrogen-15 isotope because they almost exclusively consume meat, which is made of nitrogen-rich amino acids. And animals living in cold, dry places tend to consume a higher abundance of the heavy oxygen-18 isotope in what they eat and drink because the heavy isotope doesn’t evaporate from that environment as easily as it does in warm, wet conditions.

1-30-19 Alzheimer’s bacterial link reiterates the importance of our microbiome
A bacterium seems to cause Alzheimer's as well as gum disease, hinting that our microbial denizens may be involved in many diseases we thought weren't infectious. THE suggestion that a bacterium behind gum disease could be the long-elusive cause of Alzheimer’s is an early contender for most astounding science story of the year. If the implications of a landmark study (see “We may finally know what causes Alzheimer’s – and how to stop it”) are confirmed by future research, the finding will not only point the way towards new treatments, but may also change how we think about disease altogether. Over the past decade, we have been amazed to discover the wide-ranging roles the microbes in our guts and on our skin play in shaping our health. The delicate balance of species that make up our body’s microbiome has been implicated in everything from allergies to diabetes. In some respects, our mouths are the original microbiome. Long before the human microbiome became a flourishing field of study, the knowledge that our mouths are home to a diverse array of bacteria that can, under certain circumstances, lead to tooth decay and gum disease, was commonplace, taught to many of us as schoolchildren. That such bacteria may also play a role in Alzheimer’s disease is a dramatic swerve from previous thinking, which has focused on the idea that the condition is caused by the misregulation of two particular proteins. Only further research can tellus the extent to which one of the bacteria behind gum disease – Porphyromonas gingivalis – causes Alzheimer’s. But whatever the long-term significance of this discovery, more studies in coming years are likely to reveal the involvement of the microbiome in a range of diseases we previously thought weren’t infectious. For now, we can only hope that this latest development will bring us closer to effective treatments for a disease that brings terrible loss even before it kills.

1-31-19 Virus threatening to wipe out bananas can be destroyed using CRISPR
Genome editing has been used to destroy a virus that lurks inside many of the bananas grown in Africa. Other teams are trying to use it to make the Cavendish bananas sold in supermarkets worldwide resistant to a disease that threatens to make it impossible to grow this variety commercially in future. The banana streak virus can not only be spread from plant to plant by insects like most plant viruses. It also integrates its DNA into the banana’s genome. In places like west Africa, where bananas are a staple food, most bananas have now the virus lurking inside them. When these plants are stressed by heat or drought, the virus emerges from dormancy and causes outbreaks that can destroy plantations. And there’s nothing farmers can do. But Leena Tripathi at the International Institute of Tropical Agriculture in Kenya has now used the CRISPR genome editing method to target and destroy the viral DNA inside the genome of a banana variety called Gonja Manjaya. The plan is to use these plants to breed virus-free plants for farmers. Her team is also using CRISPR to make the bananas resistant to the virus, so they are not simply re-infected. But the legal status of genome-edited plants in the west African countries where Gonja Manjaya is grown remains uncertain. “I think right now they are in discussions about whether it requires legislation,” says Tripathi. The banana streak virus does not infect the popular Cavendish banana. But a fungal strain called Tropical Race 4 is devastating Cavendish plantations as it spreads around the world. Before the 1960s the most popular banana was the reportedly more delicious Gros Michel, which farmers had to stop growing because of the spread of another fungal strain called Tropical Race 1.

1-31-19 No, we don’t know that gum disease causes Alzheimer’s
A new study suggests a link between oral bacteria and Alzheimer’s, but it’s far from proven. A study published January 23 in Science Advances — and the news stories that it inspired — might have scared you into better oral hygiene by claiming to find a link between gum bacteria and Alzheimer’s disease. Those experiments hinted that the gum disease–causing bacteria Porphyromonas gingivalis was present in the brains of a small number of people who died with the degenerative brain disease. Some headlines trumpeted that the cause of Alzheimer’s had finally been found. Enzymes made by P. gingivalis, called gingipains, interact with key Alzheimer’s proteins called amyloid-beta and tau in test tube experiments and in the brains of mice, the researchers found. Gingipains prod A-beta to accumulate and tau to behave abnormally, both signs of Alzheimer’s disease in people, the experiments suggest. And compounds that block gingipains seemed to reduce the amount of A-beta in the infected mice. The findings “offer evidence that P. gingivalis and gingipains in the brain play a central role” in the development of Alzheimer’s disease, the researchers write in their study. The research was paid for and conducted in part by employees of Cortexyme, Inc., a San Francisco–based biotech company that’s developing these compounds. The results fit with an idea that’s gaining traction among Alzheimer’s researchers — that bacteria, viruses and even fungi could spark the disease (SN: 7/21/18, p. 10). But the Science Advances study is far from conclusive, cautions Rudolph Tanzi, an Alzheimer’s researcher at Massachusetts General Hospital in Boston. Science News asked him what the study can, and can’t, answer about Alzheimer’s disease. His responses are edited for length and clarity.

1-30-19 Alzheimer’s bacterial link reiterates the importance of our microbiome
A bacterium seems to cause Alzheimer's as well as gum disease, hinting that our microbial denizens may be involved in many diseases we thought weren't infectious. THE suggestion that a bacterium behind gum disease could be the long-elusive cause of Alzheimer’s is an early contender for most astounding science story of the year. If the implications of a landmark study (see “We may finally know what causes Alzheimer’s – and how to stop it”) are confirmed by future research, the finding will not only point the way towards new treatments, but may also change how we think about disease altogether. Over the past decade, we have been amazed to discover the wide-ranging roles the microbes in our guts and on our skin play in shaping our health. The delicate balance of species that make up our body’s microbiome has been implicated in everything from allergies to diabetes. In some respects, our mouths are the original microbiome. Long before the human microbiome became a flourishing field of study, the knowledge that our mouths are home to a diverse array of bacteria that can, under certain circumstances, lead to tooth decay and gum disease, was commonplace, taught to many of us as schoolchildren. That such bacteria may also play a role in Alzheimer’s disease is a dramatic swerve from previous thinking, which has focused on the idea that the condition is caused by the misregulation of two particular proteins. Only further research can tellus the extent to which one of the bacteria behind gum disease – Porphyromonas gingivalis – causes Alzheimer’s. But whatever the long-term significance of this discovery, more studies in coming years are likely to reveal the involvement of the microbiome in a range of diseases we previously thought weren’t infectious. For now, we can only hope that this latest development will bring us closer to effective treatments for a disease that brings terrible loss even before it kills.

1-30-19 Gum disease and Alzheimer’s: Your questions answered
People are questioning a landmark study suggesting that a bacterium involved in gum disease may also cause Alzheimer's. Here's what you need to know about the study. The publication of evidence that gum disease bacteria may cause Alzheimer’s has prompted questions on social media about how seriously we should take the results. Here’s what you need to know about the landmark study.

  1. Does the study show that the bacteria cause Alzheimer’s disease, or just that the two are linked in some way? Any well-informed reader will know that correlation doesn’t mean causation, and not every link between two factors implies that one causes the other.
  2. But that’s in mice – what about humans? There are hints that the same may be true in humans.
  3. Isn’t this study too small to say anything? While 54 people isn’t a huge sample, it is large by the standards of much brain research, where tissue can be hard to get.
  4. Can we trust a study from a pharmaceutical firm? The study involved researchers from Cortexyme, a pharmaceutical firm in San Francisco that is developing treatments that interfere with P. gingivalis and its toxic gingipains.

1-30-19 Vaping beats nicotine gum at helping people quit smoking
Vaping really does appear to help people stop smoking better than old-style nicotine patches and gum. Quit rates were nearly twice as high in people who switched to e-cigarettes than in those who used other nicotine-replacement therapies in a recent trial. Vaping really does appear to help people stop smoking better than old-style nicotine patches and gum. Quit rates were nearly twice as high in people who switched to e-cigarettes than in those who used other nicotine-replacement therapies in a recent trial. E-cigarettes have long been suspected to be the superior quitting aid, but the only previous head-to-head trial used an early version that didn’t deliver much nicotine and so didn’t show any difference in quit rates compared to patches. Peter Hajek of Queen Mary University of London and colleagues wanted to put modern refillable e-cigarettes to the test, which give a bigger hit. They randomly assigned 900 smokers to use either these e-cigarettes or other nicotine-replacement therapies of their choice, which were given free for three months. For the first month participants also saw a stop-smoking advisor once a week and were tested to see if they were on the straight and narrow. About 18 per cent of those who tried vaping hadn’t gone back to smoking after a year, compared with 10 per cent of the other group. Hajek says doctors should tell people who want to quit that vaping gives them more chance of success – but people’s personal preferences come into play too. “There will still be a role for both methods.”

1-30-19 Staying slim isn’t just about what you eat – it’s about your DNA too
LOTS of people have skinny friends who claim not to put on weight even if they eat unhealthy foods. It turns out they may not be lying, after the discovery of several pieces of DNA associated with lower body weight. These suggest a genetic basis for being slim. The findings also suggest thinness may be heritable. We already know about a link between genes and obesity, so Sadaf Farooqi at the University of Cambridge and her colleagues wanted to know if slimness is also encoded in our DNA. The team collected genomic data from more than 1400 people who have always been lean. Although their body mass indexes (BMI) were in the range labelled as underweight, all were in good health. Farooqi compared their DNA with that of 1400 people who became obese before the age of 10, and 6400 individuals with BMIs in the normal range. The team found some genetic markers are significantly more common in thin people. In total, genetics accounted for about 28 per cent of someone’s likelihood of being thin, which is comparable with the strength of the genetic link to obesity. Moreover, the team found that those who have been obese since childhood carry more genes that increase their risk of being obese. In contrast, thin individuals have fewer obesity related genes (PLoS Genetics, doi.org/cz2c). “We hope this will reduce the stigma and prejudice towards obesity by recognising that thin people are just lucky – they have inherited genes that allow them to stay thin,” says Farooqi.

1-30-19 Siberian cave reveals secrets of its mysterious Denisovan inhabitants
Denisova cave in Siberia was home to an ancient group of humans – and now we get a glimpse of some of the beautiful artefacts they left behind. ALMOST a decade ago, researchers sequenced DNA from an ancient bone fragment to reveal that it belonged to a woman from an entirely new group of humans. After years of waiting, we are now getting our first glimpse of the only confirmed home of the Denisovans. Named after the Denisova cave in Siberia, where the ancient bone was found, these humans lived in Stone Age Eurasia alongside our species and the Neanderthals. Although we have discovered more about these people since the bone was discovered (see “Who lived in a cave like this?”), we have heard very little about Denisova cave. That has now changed after an international team of researchers published two papers that make it clear the cave is every bit as extraordinary as its ancient occupants. Not only do the papers give us a better understanding of who lived there and when, they reveal some of the objects those residents made. “Some of the material is beautiful,” says Thomas Higham at the University of Oxford. “We think it may be the earliest of its kind in Eurasia.” Denisova cave lies in the Altai mountains of southern Siberia, a few hundred kilometres from the Russian border with Kazakhstan, Mongolia and China. Higham says the place is “almost magical”, with its Alpine-like scenery, wild horses and soaring eagles. “It’s rather like Switzerland, but without as many people,” he says.

1-30-19 New dates narrow down when Denisovans and Neandertals crossed paths
The extinct hominids periodically occupied the same Siberian cave starting 200,000 years ago. Mysterious ancient hominids known as Denisovans and their evolutionary cousins, Neandertals, frequented a southern Siberian cave starting a surprisingly long time ago, two new studies find. Evidence for visits by those populations to Denisova Cave, beginning by around 200,000 years ago for Neandertals and possibly as early as about 300,000 years ago for Denisovans, appears in the Jan. 31 Nature. It was known that members of the two extinct hominid species had occupied the Siberian cave at a few points during the Stone Age. But the new evidence offers the best look to date at when Denisovans and Neandertals reached the site, and how the two hominid species may have interacted, including interbreeding. In one new study, a team led by geoarchaeologist Zenobia Jacobs found that Denisovans occupied the Siberian cave as recently as around 55,000 years ago, while a second investigation, directed by archaeologist Katerina Douka, places the Denisovans’ last stand at the site in roughly the same ballpark. As for Neandertals, they last inhabited Denisova Cave roughly 97,000 years ago, Jacobs’ group estimates. “It now looks like Denisovans can be placed at the site from close to 300,000 years ago to about 50,000 years ago, with Neandertals there for periods in between,” says paleoanthropologist Chris Stringer of the Natural History Museum in London who did not participate in the research. But it’s still uncertain whether hominid fossils from the cave derive from individuals who died during periodic occupations or whose remains were transported to the site by, say, carnivores, he says.

1-30-19 Life’s secret ingredient: A radical theory of what makes things alive
How does inanimate matter come to breathe, thrive and reproduce? Explaining this magic means overhauling nature’s laws, says physicist Paul Davies THERE is something special – almost magical – about life. Biophysicist Max Delbrück expressed it eloquently: “The closer one looks at these performances of matter in living organisms, the more impressive the show becomes. The meanest living cell becomes a magic puzzle box full of elaborate and changing molecules.” What is the essence of this magic? It is easy to list life’s hallmarks: reproduction, harnessing energy, responding to stimuli and so on. But that tells us what life does, not what it is. It doesn’t explain how living matter can do things far beyond the reach of non-living matter, even though both are made of the same atoms. The fact is, on our current understanding, life is an enigma. Most strikingly, its organised, self-sustaining complexity seems to fly in the face of the most sacred law of physics, the second law of thermodynamics, which describes a universal tendency towards decay and disorder. The question of what gives life the distinctive oomph that sets it apart has long stumped researchers, despite dazzling advances in biology in recent decades. Now, however, some remarkable discoveries are edging us towards an answer. Three-quarters of a century ago, at the height of the second world war, Erwin Schrödinger, one of the architects of quantum physics, addressed this question directly in a series of lectures and then a book entitled What is Life?. He left open the possibility of there being something fundamentally new at work in living matter, beyond our existing conception of physics and chemistry. “We must… be prepared to find a new type of physical law prevailing in it,” he wrote. Scientists since have tended to dismiss Schrödinger’s suggestion, preferring to think that our difficulties in understanding life stem not from anything fundamental, but from the sheer complexity of living organisms. As they have attempted to get to grips with this complexity, they have developed two very different ways of talking about life.

1-30-19 Genome sequencing could become a routine part of health care in the UK
The UK wants to be one of the first countries to make whole genome sequencing a routine part of medical care. But dealing with the flood of data, sharing it with researchers and companies without breaching confidentiality, and informing patients of relevant and potentially disturbing findings will not be easy. In December, the UK finished sequencing the genomes of the 85,000 participants in its 100,000 Genomes Project. It is claiming great results. In people with cancer, half of all genomes “contain potential for a therapy or a trial”, said Mark Caulfield at Genomics England, a company owned by the UK’s health ministry, speaking at the Festival of Genomics meeting in London last week. For those with rare diseases, a quarter of genomes have revealed “actionable findings”. This genome data is now starting to be used to tailor drug treatments to patients — for instance, to reveal which are likely to suffer serious side effects. Caulfield hopes this will become routine. “What if we carry round on our phone our pharmacogenetic profile?” he asked. This is already happening elsewhere. In Estonia, 15 per cent of the population totaling 155,000 people have had their genomes sequenced, and doctors already use this information when prescribing, said Andres Metspalu at the University of Tartu at the same meeting. In the UK, new technology is also being used to detect genes containing lots of repeats of short bits of DNA — the genetic equivalent of a stuck record — which can cause diseases such as Huntington’s. This raises tricky ethical issues as some people may not want to know if they have Huntington’s, but other members of their families who have inherited the same DNA might do. Now the aim is to sequence 5 million genomes. How this would be funded Caulfield did not say. But shortly afterwards the UK health secretary announced that healthy people will be able to pay to get their genomes sequenced. For those with serious diseases, it will be free. (Webmaster's comment: Another country taking the technological lead.)

1-29-19 Using CRISPR to stop male calves being born may lower animal suffering
For many livestock animals, being born male means an instant death sentence. Male dairy calves are unwanted because they do not produce milk, while male chickens are routinely killed as soon as they hatch because they do not lay eggs. Now researchers are proposing a radical solution to this slaughter: genetically engineering the animals we eat so that they mostly produce female offspring. The idea could reduce animal suffering and improve farms’ profitability, but is likely to collide with public opposition to genetically-modified organisms. Researchers led by Motti Gerlic and Udi Qimron of Tel Aviv University in Israel have devised a system to ensure that male animals are rarely born. They worked with mice, which are not livestock animals, so their study is a proof of principle rather than something that could immediately be used on farms. Like humans, female mice have two X chromosomes while males have one X and one Y. The researchers used CRISPR gene editing to automatically destroy Y-chromosomes in unborn embryos, causing them to abort at an early stage. The team modified the genome of one group of mice to include a key CRISPR enzyme called Cas9, which cuts DNA in specified places. In a second group of mice, they added markers to three genes on the Y chromosome, making them a target for Cas9. Each gene is essential for embryos to develop, so damaging even one of them would cause the embryo to abort. They targeted three to be extra sure. In theory, when these two lines of modified mice mated with each other, only female offspring should have been born. The team found that such crosses produced just three males for every 20 females, so the method shows promise, but may need to target more genes to be fully effective.

1-29-19 Epigenetic testing firms claim to help you live a healthier lifestyle
Getting your DNA sequenced is now an everyday reality, but a new frontier has opened up in personal genomics. Two companies have started selling kits that sequence your epigenome. They claim it can deliver much more detailed and useful health advice than is possible from a regular gene sequence. Epigenetics refers to biochemical modifications to DNA that occur during a person’s lifetime in response to lifestyle and environment. These alter the expression of genes and can have a profound effect on health. Detrimental effects can sometimes be reversed, and beneficial ones encouraged, by lifestyle changes. The two companies say they will help their customers to shift their epigenomes into a healthier state. Chronomics, based in Norwich, UK, has been selling its services since April last year. Muhdo Health of Ipswich, UK, is launching its kit this week. The companies’ sales pitches are similar. Both say they will sequence your epigenome, use it to assess various measures of health, and offer advice on how to improve it. This advice is what sets epigenetic testing from regular personal genomics, says Tom Stubbs, CEO and founder of Chronomics. “With genetics, people can’t do anything about the information they’re given. With epigenetics, that’s not the case,” he says. “If you found out you had a bad score on something there are steps you could take to improve it. It’s much more empowering.” There are many forms of epigenetic modification but the best understood is methylation, where a methyl group is chemically attached to the DNA base cytosine. Most methylations switch genes off. Both companies’ tests look at methylation status across the entire genome. Stubbs says Chronomics’ test uses state-of-the-art sequencing to analyse 5 million bases where methylation can occur – just a small fraction of the genome, but the most important parts when it comes to epigenetics.

1-29-19 We’ve only just found out exactly how sperm wiggle their tails to swim
We thought we had sperm figured out, but it turns out they wiggle in mysterious ways. The finding could shed light on why some men have fertility problems, and lead to more accurate diagnostic tests for infertility. Sperm move forward by wiggling their long tails, taking several hours to travel from the vagina, through the womb, to reach an egg in the fallopian tubes. They also have another kind of behaviour, called hyperactivation, when they beat their tails more strongly and asymmetrically. This makes them jerk around randomly and so cover less ground. We had thought that sperm only switch to this mode when they reach the egg, in order to burrow through its outer wall. But Stephen Publicover of the University of Birmingham, UK and his colleagues have found that fresh sperm in fact swap repeatedly between normal swimming and hyperactivation. “Rather than starting off in one stroke and ending up in another, they’re switching back and forwards all the time.” They filmed individual sperm in a dish for three minutes at a time, and found that 16 out of 18 showed these abrupt switches, changing on average every 10 seconds. The findings were presented at the Fertility 2019 conference in Birmingham in the UK earlier this month. This suggests that hyperactivation is not just a way of getting inside the egg, says Publicover. But it’s unknown what other purpose it could serve. It’s hard to study human sperm inside a woman’s body, but we have clues from animal research. Susan Suarez of Cornell University in New York, says hyperactivated sperm in mice seem better at escaping from pockets in the wall of the fallopian tube.

1-29-19 Neanderthals may have been sprinters not endurance runners
We may have to rewrite what we know about Neanderthals — they were sprinters rather than long distance joggers, and occupied forests, not bleak tundra-like wasteland. Neanderthals died out around 40,000 years ago. Evidence had suggested they were adapted to the cold, harsh conditions of the last ice age and Neanderthal fossil remains have often been associated with ice age mammals such as mammoths, woolly rhinos, horses and reindeer. However, a new analysis suggests a different view. “A closer look at the layers in which their fossils are found suggest Neanderthals actually lived at the same times and places as animals that are associated with warmer, woodland ecologies,” says John Stewart at the University of Bournemouth, who led the study. In such an environment, hunting in short bursts would be more favoured, says Stewart, “more power sprint than endurance jog.” This conclusion was also backed up by a genetic analysis that found a high proportion of gene variants linked to power sports performance in modern-day athletes in the Neanderthal genetic code. “We found that the majority of these power-associated genetic variants were typically more common in Neanderthals than in humans today, who are known to be more endurance-adapted, reflecting their generally more slender builds,” says Yoan Diekmann, a member of the team at University College London. Neanderthals belonged to a separate branch of the human family tree to modern humans, but the two co-existed in Europe for thousands of years. They were already in Europe and Asia long before the ancestors of people living today migrated out of Africa.

1-28-19 Why modern javelin throwers hurled Neandertal spears at hay bales
Some extinct hominids didn’t just stab prey from a close distance, a study finds. Archaeologist Annemieke Milks had convened a sporting event of prehistoric proportions. The athletes: Six javelin throwers who approached the physical strength of Neandertals. The weapon: Two replicas of a 300,000-year-old wooden spear, one of nine ancient hunting tools discovered at Germany’s Schöningen coal mine (SN: 3/1/97, p. 134). The test: Could Neandertals, the likely makers of the Stone Age weapon, have hurled the spears at prey with any power, accuracy and distance? Many researchers have suspected that Neandertals or their ancestors snuck up on and stabbed prey with the pointed wooden rods. That idea aligns with a popular assumption that Stone Age Homo sapiens had a monopoly on hurling spears at prey. Yet bodies capable of accurate and powerful throwing may have emerged nearly 2 million years ago in Homo erectus (SN Online: 6/26/13). So why not Neandertals? Now data from high-speed video cameras at Milks’ unusual throw-off, held in January 2015 and reported online January 25 in Scientific Reports, suggest that Neandertals might have used the spears for long-range hunting. Athletes threw the two wooden spear replicas a total of 102 times at bales of hay, hitting bales five meters away 58 percent of the time. That figure fell to 25 percent for throws from 10 meters and 15 meters, and 17 percent for 20-meter throws. No one could hit hay bales placed 25 meters away. The results are the first measurements of the Schöningen projectiles’ flight characteristics when hurled at a target.

1-28-19 The GM chickens that lay eggs with anti-cancer drugs
Researchers have genetically modified chickens that can lay eggs that contain drugs for arthritis and some cancers. The drugs are 100 times cheaper to produce when laid than when manufactured in factories. The researchers believe that in time production can be scaled up to produce medicines in commercial quantities. The chickens do not suffer and are "pampered" compared to farm animals, according to Dr Lissa Herron, of Roslin Technologies in Edinburgh. "They live in very large pens. They are fed and watered and looked after on a daily basis by highly trained technicians, and live quite a comfortable life. "As far as the chicken knows, it's just laying a normal egg. It doesn't affect its health in any way, it's just chugging away, laying eggs as normal." Scientists have previously shown that genetically modified goats, rabbits and chickens can be used to produce protein therapies in their milk or eggs. The researchers say their new approach is more efficient, produces better yields and is more cost-effective than these previous attempts. "Production from chickens can cost anywhere from 10 to 100 times less than the factories. So hopefully we'll be looking at at least 10 times lower overall manufacturing cost" said Dr Herron. The biggest saving comes from the fact that chicken sheds are far cheaper to build and run than highly sterile clean rooms for factory production. Many diseases are caused because the body does not naturally produce enough of a certain chemical or protein. Such diseases can be controlled with drugs that contain the deficient protein. These drugs are synthetically produced by pharmaceutical companies and can be very expensive to manufacture. Dr Herron and her colleagues managed to reduce the costs by inserting a human gene - which normally produces the protein in humans - into the part of the chickens' DNA involved with producing the white in the chickens' eggs.

1-28-19 How light-farming chloroplasts morph into defensive warriors
Scientists have identified the protein that summons the cellular energy factories to battle. Chloroplasts may seem like docile farmers of light. But inside these microscopic plant and algal cell structures lurks the spirit of a warrior. When a pathogen attacks a plant, chloroplasts stop making food from sunlight and rush to the site of infection to help fend off the invader. Now, researchers have identified the protein that mobilizes these organelles into a defensive army. Plant pathologist Tolga Bozkurt of Imperial College London and colleagues infected a tobacco relative (Nicotiana benthamiana) with the Irish potato famine pathogen (Phytophthora infestans), a funguslike microbe. The team suspected that a protein called chloroplast unusual positioning 1, or CHUP1, plays a role in rallying chloroplasts for defense. The protein is better known for helping move chloroplasts to where light enters the cell and then attaching the organelles to the cell membrane there. In experiments, when researchers silenced the gene for CHUP1, chloroplasts mostly didn’t respond to an infection. But when the gene was active, chloroplasts shut off their photosynthetic machinery and formed a defensive onslaught, the researchers report January 9 at bioRxiv.org.

1-27-19 Vitamin D supplements aren’t living up to their hype
Recent studies say taking extra amounts of the nutrient may not be a boon for every body. In the supplement world, vitamin D is a bit like a Kardashian. Its fame seemed to come out of nowhere about a decade ago, garnering so much press so fast that it’s hard to remember a time when people weren’t talking about it. Vitamin D had long been known for protecting bones, but its star began to rise in the early 2000s after researchers made connections hinting that vitamin D was good for a lot more than our skeletons. It appeared to help protect against a lengthy list of ailments, including multiple sclerosis, asthma, depression, heart disease and cancer. The vitamin also was said to improve athletic performance. Organizations like the Vitamin D Council — the 2003 brainchild of a psychiatrist who became a vitamin D enthusiast — began to actively promote the benefits to the public and to physicians, while selling test kits for vitamin D blood levels. Doctors checked for it; patients demanded testing. Researchers latched on. But with more research comes more scrutiny, and most recently, a series of seemingly tarnishing findings. On November 10, the New England Journal of Medicine published the largest study so far to test vitamin D supplements’ protection against cancer and heart disease. The results were generally interpreted as inconclusive at best and disappointing at worst. One 2017 review of the evidence for cardiovascular benefits concluded that studies of people taking vitamin D “have failed to show clear improvements in blood pressure, insulin sensitivity or lipid parameters.”

1-25-19 Sleep loss and heart disease
A terrible night’s sleep isn’t just bad for your mood—it could also damage your heart, according to a new Spanish study. Researchers recruited nearly 4,000 people with an average age of 46 and no known history of heart disease, and for seven nights had them wear a small device that measures the length and quality of sleep. The participants also had a cardiac CT scan and 3-D ultrasounds of their heart and arteries at the start and end of the study. After factoring out other risk factors for heart disease, the team found that people who slept for fewer than six hours a night were 27 percent more likely to have atherosclerosis—the buildup of plaque in the body’s arteries, a common cause of heart attacks and strokes—than those who slept seven to eight hours. Those who woke often during the night or who struggled to doze off were 34 percent more likely to have the condition than those who got a good night’s snooze. “We have to include sleep as one of the weapons we use to fight heart disease,” lead researcher José Ordovás tells USA Today. It’s “a factor we are compromising every day.”

1-25-19 Fiber’s many benefits
n a blow to proponents of low-carbohydrate diets, a landmark study has found that people who eat more fiber—found in fruit, vegetables, and whole-grain cereals, pasta, and bread—are less likely to die early or suffer from a chronic condition such as cardiovascular disease or cancer. An international team of researchers, commissioned by the World Health Organization, analyzed more than 180 studies and 50 clinical trials from the past 40 years. They found that people who ate the most fiber were 15 to 30 percent less likely to die prematurely than those who ate the least. Those heavy fiber consumers were also 16 to 24 percent less likely to suffer a stroke or develop heart disease, type 2 diabetes, or colorectal cancer. The optimal fiber intake, researchers determined, was 25 to 29 grams a day; American adults consume an average of 15 grams. The study is a “defining moment” in dietary fiber research, co-author John Cummings of the University of Dundee tells TheGuardian.com. “We need to get this written in stone and part of people’s lives.”

1-25-19 Dogs may have helped ancient Middle Easterners hunt small game
Bones unearthed in Jordan hint the canines weren’t primarily used to target big game. Dogs that lived alongside Middle Eastern villagers roughly 11,500 years ago may have helped to transform how those humans hunted, researchers say. Fragmentary canine bones unearthed at Shubayqa 6, an ancient site in northeastern Jordan, date to a time when remains of hares and other small prey at the outpost sharply increased, say zooarchaeologist Lisa Yeomans of the University of Copenhagen and her colleagues. Many animal bones from Shubayqa 6 also display damage caused by having been swallowed by dogs and then passed through their digestive tracts, the scientists report in the March Journal of Anthropological Archaeology. “The use of dogs for hunting small, fast prey such as hares and foxes, perhaps by driving them into enclosures, could explain the evidence at Shubayqa 6,” Yeomans says. The bone fragments challenge a long-standing idea that, in the early stages of domestication, dogs were first used to hunt large animals that yielded lots of meat per kill, she says. In that scenario, population growth and climate fluctuations led to food shortages for foraging groups. People seeking a wider array of plants and animals in their diet then incorporated dogs into small-game hunts too. That dietary shift heralded the rise of farming, researchers have suggested. The bone fragments challenge a long-standing idea that, in the early stages of domestication, dogs were first used to hunt large animals that yielded lots of meat per kill, she says. In that scenario, population growth and climate fluctuations led to food shortages for foraging groups. People seeking a wider array of plants and animals in their diet then incorporated dogs into small-game hunts too. That dietary shift heralded the rise of farming, researchers have suggested.

1-25-19 Neanderthals 'could kill at a distance'
Neanderthals may once have been considered to be our inferior, brutish cousins, but a new study is the latest to suggest they were smarter than we thought - especially when it came to hunting. The research found that the now extinct species were creating weaponry advanced enough to kill at a distance. Scientists believe they crafted spears that could strike from up to 20m away. The study is published in the journal Scientific Reports. Lead researcher Dr Annemieke Milks, from UCL Institute of Archaeology, said: "The original idea was that Neanderthals would have been very limited using hand-delivered spears, where they could only come up at close contact and thrust them into prey. "But if they could throw them from 15m to 20m, this really opens up a wider range of hunting strategies that Neanderthals would have been able to use." The researchers looked at wooden spears that were excavated in Schöningen in Germany in the 1990s. Made from spruce, they are estimated to be around 300,000 years old and were discovered along with thousands of bone fragments. The team tested the performance of these weapons by creating replicas - and then handed them to javelin athletes who attempted to hit a target from a range of distances. "Javelin athletes are definitely not a perfect proxy for Neanderthals," admitted Dr Milks. "But previously we relied on unskilled people to thrust or throw these weapons in experimental work, so our ideas about how they functioned are based on unskilled use." It had been thought that the spears, weighing 760-800g, were too heavy to travel at significant speed with enough accuracy to be used as long-distance weapons. But the team found that the athletes could hurl the replicas to accurately reach a target up to 20m away. "The distances are much more than is currently suggested, but also they impacted with significant energy, enough to kill large prey," said Dr Milks. "This really opens up the Neanderthal behavioural repertoire of hunting. We're having more and more evidence of just how clever Neanderthals were," she added. The study is the latest to suggest our original view of Neanderthals as hulking, dim-witted cousins has done them a disservice. In addition to being able to craft weapons, they could also construct and use tools - and even built objects on a larger scale, such as mysterious stone rings found underground in France. Other archaeological evidence shows that some Neanderthals looked after their sick and buried their dead, while a recent paper suggested they could also turn their hand to art - with the discovery of cave paintings in three sites in Spain. They also bred with humans - leaving a legacy of a small amount of their DNA in present-day Europeans, Asians and Oceanians.

1-24-19 Viewpoint: Why we still underestimate the Neanderthals
Prof Clive Finlayson, director of the Gibraltar Museum, explains why some old assumptions about the intellectual capabilities of our evolutionary relatives, the Neanderthals persist today. But a body of evidence is increasingly forcing us to re-visit these old ideas. A paper out this week in the journal Nature Ecology and Evolution reports the early arrival of modern humans to south-western Iberia around 44,000 years ago. Why should this be significant? It all has to do with the spread of our ancestors and the extinction of the Neanderthals. South-western Iberia has been claimed to have been a refuge of the Neanderthals, a place where they survived longer than elsewhere, but the evidence is disputed by some researchers. The latest paper, which is not about Neanderthals, has been taken by some as evidence of an arrival into this area which is much earlier than previously known. By implication, if modern humans were in south-western Iberia so early then they must have caused the early disappearance of the Neanderthals. It is a restatement of the idea that modern human superiority was the cause of the Neanderthal demise. Are these ideas tenable in the light of mounting genetic evidence that our ancestors interbred with the Neanderthals? You may also have noticed some recent headlines about our Neanderthal heritage and its influence on head shape. In particular, a study found that specific DNA sequences seem to be linked to the globular shape of our skulls. Sequences linked with reduced "globularity" (a measure of roundness) are present in Neanderthals and some living people. The researchers reportedly stressed that the effects of carrying the rare Neanderthal fragments were subtle and could not be detected in a person's head shape when you met them. That was reassuring given the current rise of xenophobia and the bad press that Neanderthals have had. Neanderthals are generally considered to have been a distinct human species (Homo neanderthalensis) that once inhabited a region stretching from Siberia in the east to Iberia in the west, and from Britain in the north to Iraq in the south. They first appear around 450,000 years ago and then die out as our own species starts to settle in Eurasia, after 60,000 years ago. Not everyone agrees that they were separate species. Discoveries from genetics over the last decade or so reveal that they didn't completely go extinct. Our ancestors (to some defined as the separate species Homo sapiens), mixed with them, so that today, around 2% of the genomes of non-African people alive today is Neanderthal.

1-24-19 People appear to sleep much better when rocked throughout the night
Adults may sleep better and remember more of what they have learned beforehand when they are rocked to sleep. You shouldn’t start rearranging your bedroom just yet, however, given the study involved just 18 adults, but further trials could confirm the findings. Rocking beds might provide a new way to help people with sleeping disorders and older people who often have trouble sleeping, says Aurore Perrault of the University of Geneva. It might provide an alternative or a complement to sleeping pills, she says. Her team had previously found that rocking helped people fall asleep when having an afternoon nap. To test if it helps at night too, 18 men and women with an average age of 23 spent three nights sleeping in the lab. The first night was just to let them get used to the surroundings. Then, on either the second or third night, they were rocked throughout the night. The otherwise normal bed they slept on was suspended from posts at each corner, and pushed 10 cm to one side and back every 4 seconds. “They all rated the rocking night as pleasant and relaxing,” says Perrault. The team found that when the bed was rocked people fell asleep more easily and slept better. They spent more time in deep sleep and had fewer sleep interruptions. Before going to sleep, the volunteers had to memorise word pairs. The volunteers did better in morning tests after a night of gentle rocking sleep. The team have no idea why it works. But they have also shown that mice sleep better too when rocked, so it appears the effect isn’t limited to people or even primates. The next step is to do tests over a longer period to see if the benefits last as people get used to the rocking, says Perrault. She also wants to try it with on older people and those with sleeping disorders.

1-24-19 Rocking puts adults to sleep faster and makes slumber deeper
People’s memories also improved the next day after a night of gentle swaying. Babies love to be rocked to sleep. It turns out that we never quite grow out of it. Grown-ups tucked into a gently swaying bed for the night fell asleep faster and slept deeper, scientists report in the Feb. 4 Current Biology. What’s more, these rocked adults had sharper memories the next morning. Aside from hinting at the next great sleep aid, the results offer clues about how the brain refreshes itself each night. “We’ve been rocking our babies for thousands of years now. We know it helps them fall asleep,” says Robert Stickgold, a cognitive neuroscientist at Harvard Medical School. So why not adults? “I’m putting my bed on a rocker tonight,” he says, calling the results “a lot of fun.” Neuroscientist Laurence Bayer of the University of Geneva and her colleagues first got a hint that adults might benefit from rocking in 2011. The researchers found that adults napped better in a custom-built rocking bed — a contraption that gently sways back and forth every four seconds, moving 10½ centimeters each way. But it wasn’t clear whether rocking might improve sleep across an entire night. So for the new study, Bayer and her colleagues invited 18 healthy young adults for several laboratory sleepovers, with one night spent on a rocking bed and one night spent on a stationary one. All the while, the researchers measured the people’s brain activity by electroencephalogram, or EEG, which can spot electrical signs of certain sleep stages.

1-24-19 Lack of sleep is tied to increases in two Alzheimer's proteins
It’s not just A-beta levels that rise in the sleep deprived; tau levels do too. A sleep-deprived brain is awash in excess amounts of not one but two proteins whose bad behavior is implicated in Alzheimer’s disease. A new study finds excessive amounts of a protein called tau in the fluid that bathes the brain and spinal cord of extremely sleep-deprived adults. Tau, which is tied to nerve cell death, tangles and spreads throughout the brain during Alzheimer’s. An earlier report on these sleepy adults found that the protein amyloid-beta — globs of which dot the brains of Alzheimer’s patients — also increased. Samples of cerebrospinal fluid collected from eight adults, monitored during a night of normal sleep and over the course of 36 hours of sleep deprivation, revealed a 51.5 percent increase in tau in participants robbed of shut-eye. And sleep-deprived mice had twice the amount of tau as well-rested mice, researchers report online January 24 in Science. Earlier work by these researchers had suggested that the quality of sleep might affect tau levels; this time, it’s been linked to duration of sleep. With both A-beta and tau increasing with a lack of sleep, “it certainly argues that treating sleep disorders during mid-life as well as getting appropriate levels of sleep is likely to decrease risk for Alzheimer’s disease,” says coauthor David Holtzman, a neurologist and neuroscientist at Washington University School of Medicine in St. Louis. During sleep, the brain appears to flush out excess proteins and other debris (SN: 7/21/18, p. 22), so perhaps less sleep means that wash cycle is curtailed.

1-24-19 Staying slim isn’t just about what you eat – it’s about your DNA too
Many people have skinny friends who claim not to gain weight even if they eat unhealthily. They may not be lying. Several pieces of DNA turn out to be associated with lower body weight, suggesting a genetic basis for slimness. The findings also suggests thinness may be heritable. Previous research has suggested that about 40 to 70 per cent of variation in our body weight can be explained by genetics. Scientists have discovered a link between genes and obesity, so Sadaf Farooqi at the University of Cambridge and her colleagues wanted to know if slimness is also encoded in our DNA. The team collected genomic information from over 1400 individuals who have always been lean. Although their BMIs are below the normal cutoff, all of the individuals are in good health. Farooqi compared their DNA with that of 1400 individuals who became obese before the age of 10, and 6400 individuals with normal body weight. The team found some genetic markers are significantly more common in thin people. In total, genetics accounted for about 28 per cent of someone’s likelihood of being thin – which is comparable to the strength of the genetic link to obesity. “We show for the first time that genes can also be linked to thinness,” Farooqi says. Moreover, the team found those who have been obese since childhood carry more genes that increase their risk of being obese. In contrast, thin individuals have fewer obesity-related genes. “This work is the first step in finding the pathways that we can target to develop new weight loss treatments,” Farooqi says. “We hope this will reduce the stigma and prejudice towards obesity by recognising that thin people are just lucky – they have inherited genes that allow them to stay thin.”

1-24-19 Tiny eyes make a bizarre, ancient platypus-like reptile even weirder
The creature lived about 250 million years ago. Two newly found specimens of the mysterious, platypus-like reptile suggest that the ancient creature had very small eyes for its size, and may have hunted mainly by touch. That makes E. carrolldongi the oldest known amniote — a group that includes reptiles and mammals — to use a sense other than sight to find its prey, scientists report online January 24 in Scientific Reports. E. carrolldongi, which lived about 250 million years ago, is one of numerous strange creatures dating to the Early Triassic described by scientists in recent years. It is part of an oddball array of marine reptiles called Hupehsuchia that lived in a vast lagoon spanning hundreds of kilometers across what’s now southern China. That flourishing of forms, which came on the heels of the mass extinction at the end of the Permian Period 252 million years ago, suggests that marine reptiles diversified millions of years earlier than once thought, the researchers say. E. carrolldongi was named in part for its large, fan-shaped flippers, which give its body a passing resemblance to a platypus (Eretmorhipis means “oar fan”). Now, the newly discovered specimens, the first with skulls, point to one more thing that the ancient swimmer had in common with the modern platypus: very small eyes. The creature also had a small head, meaning that it probably didn’t use hearing to forage, given the challenge of localizing sound in water. Chemoreception — used by snakes, for example, to gather information from the atmosphere through their tongues — is also unlikely based on the lack of certain telltale holes the skull, say paleontologist Long Cheng of the Wuhan Centre of China Geological Survey and colleagues.

1-24-19 Gum disease may be the cause of Alzheimer’s – here’s how to avoid it
Bacteria that cause gum disease have been implicated as a cause of dementia. Here’s what you need to know.

  1. What is gum disease and why should I be worried about it?
  2. : Gum disease, also known as gingivitis in its mild form, occurs when bacteria accumulate in tooth plaque, causing inflammation, receding gums and bleeding. If it progresses to the more serious form, periodontitis, it can lead to abscesses and tooth loss.
  3. So why are we talking about it now? It turns out that one of the key bacteria that cause gum disease – Porphyromonas gingivalis – may also be the root cause of Alzheimer’s disease, a form of dementia.
  4. How do I know if I have gum disease? ccasional bleeding from the gums when you clean or floss your teeth doesn’t definitely mean you have it, as you may just have been too rough. But dentists advise that any bleeding should be checked out. Other signs include soreness around the gums and bad breath.
  5. What should I do about it? Researchers are working on a vaccine and a specific anti-toxin for P. gingivalis, but these are some years away from reaching the clinic. Until then, your best bet is taking the usual steps to avoid gum disease.
  6. Which are? Listening to your dentist, for a start. They advise cleaning your teeth twice a day, and flossing or using interdental sticks to get plaque out from the gaps. Too vigorous brushing can get oral bacteria into the bloodstream, so take it easy. But if plaque is allowed to build up it can become mineralised, turning into hard tartar, which encourages the growth of more plaque towards the tooth roots.

1-23-19 Powerful whole-species gene editing tool fails first tests in mice
When it comes to mammals, both the optimism and the fears about gene drives are overblown. So say a team who have tested the concept in mice for the first time. Their studies in mice suggests that existing gene drives don’t work nearly well enough to be used to eliminate mammalian pests – invasive rodents on islands, for instance. On the flip side, this means that gene drives would pose little danger to, say, wild mice if one somehow got out of a lab. “I think we were all a little surprised because it works so well in insects,” says Kimberly Cooper of the University of California San Diego. The gene drive concept emerged about 15 years ago. Most animals have two copies of the genome, but pass on only one copy to their offspring. The other parent contributes the second copy. This means there’s only a 50 per cent chance that any one offspring will inherit a specific piece of DNA from one parent. Gene drives are pieces of DNA that cheat. They “copy and paste” themselves from one genome copy to a target sequence in the other copy. In theory, that means there’s a 100 per cent chance that all offspring will inherit the gene drive and that it will spread through a population in relatively few generations. In principle, then, a gene drive that made, say, all offspring male could quickly drive a species to extinction. In practice, the copying process does not always work. In addition, animals can become resistant if mutations appear in the genome region the “paste” process targets, which can prevent copying altogether. Cooper found that in mice the copying process worked only 70 per cent of the time at best. What’s more, when the copying process failed it induced mutations in the target sequence, meaning that resistance to the gene drive could evolve very quickly and halt the spread of the drive.

1-23-19 We may finally know what causes Alzheimer’s – and how to stop it
If you bled when you brushed your teeth this morning, you might want to get that seen to. We may finally have found the long-elusive cause of Alzheimer’s disease: Porphyromonas gingivalis, the key bacteria in chronic gum disease. That’s bad, as gum disease affects around a third of all people. But the good news is that a drug that blocks the main toxins of P. gingivalis is entering major clinical trials this year, and research published today shows it might stop and even reverse Alzheimer’s. There could even be a vaccine. Alzheimer’s is one of the biggest mysteries in medicine. As populations have aged, dementia has skyrocketed to become the fifth biggest cause of death worldwide. Alzheimer’s constitutes some 70 per cent of these cases and yet, we don’t know what causes it. The disease often involves the accumulation of proteins called amyloid and tau in the brain, and the leading hypothesis has been that the disease arises from defective control of these two proteins. But research in recent years has revealed that people can have amyloid plaques without having dementia. So many efforts to treat Alzheimer’s by moderating these proteins have failed that the hypothesis has been seriously questioned. However evidence has been growing that the function of amyloid proteins may be as a defence against bacteria, leading to a spate of recent studies looking at bacteria in Alzheimer’s, particularly those that cause gum disease, which is known to be a major risk factor for the condition. Bacteria involved in gum disease and other illnesses have been found after death in the brains of people who had Alzheimer’s, but until now, it hasn’t been clear whether these bacteria caused the disease or simply got in via brain damage caused by the condition.

1-23-19 8 ways to keep your brain young and stave off mental decline
Want to defy ageing and keep your mind sharp? From the right diet to your dental hygiene and social life, here are the best ways to keep your brain fighting fit.

  1. Flex your mental muscle: The brain is often likened to a muscle, and for good reason: give it a good workout and it will stay strong.
  2. Get moving: It is one of the lesser known benefits of pounding the pavements, but regular physical exercise can do wonders for your mental fitness.
  3. Look after your ears: Your parents probably told you to wash behind your ears, but it is far more important to take care of their insides.
  4. Chill out: She found a strong correlation between tooth loss and a drop in cognitive function, even after accounting for the natural changes that occur in both with age.
  5. Find your purpose: If these tally with your working life, it also bodes well for your mind: finding a purpose in life is a sure way to stave off mental decline.
  6. Mix and mingle: And it turns out that hanging out with other people can help preserve cognitive health in a similar way to activities like learning an instrument.
  7. Get your Zs: Study after study suggests that not getting enough of the right kind of sleep can have long-term impacts on the brain.
  8. Mind what you eat: You might have heard of the benefits of the Mediterranean diet, which recommends eating plenty of fruit, vegetables, whole grains and olive oil. It does seem to keep us healthy, cutting the risk of heart disease and early death.

1-23-19 Married people have stronger hands than those who are single
Married men and women can grip objects more firmly than their unmarried counterparts. Among married men, it is those who have had more than one wife who have the strongest grip of all — and we don’t really know why. People who are married typically have better physical and psychological health than people who are single. This may be because a marriage partner can provide strong social support or encourage healthier living. Married couples also tend to have larger household incomes, which may be a part of it as wealthier people tend to be healthier. But we know less about how marriage influences physical ability, particularly in the later years of life. To investigate, Natasha Wood at University College London and her colleagues examined data collected as part of the English Longitudinal Study of Ageing and the US Health and Retirement Study. Both surveys gather data on people in their 50s or older. Wood and her colleagues looked at data on grip strength – as measured using a handheld device that participants are asked to squeeze – that was collected as part of both surveys. After adjusting for factors including age and ethnicity, the researchers found that unmarried men and women have a significantly weaker grip than men and women in their first marriage. In most cases the differences effectively vanished when the researchers factored in wealth status, suggesting it’s the extra income that marriage typically brings that might explain the results. But Wood and her colleagues found one result that couldn’t be explained by money. “Remarried men had a stronger grip strength independent of wealth,” says Wood. It isn’t clear why that’s the case, but the team raise one idea that might be worth exploring.

1-23-19 Tumour-killing virus could stop a childhood eye cancer and save vision
A cancer-killing virus may be able to remove tumours associated with retinoblastoma, a rare eye cancer usually diagnosed in children before the age of 3. The hope is that this approach will prevent the need for eye removal surgery to stop the cancer from spreading to the brain. Currently, chemotherapy is the first line of attack, but this fails in around 30 per cent of cases because the tumour becomes resistant to the drugs, leaving surgery as the only remaining option. Children who have the type of retinoblastoma based on an inherited genetic mutation, which leads to tumours in both eyes, are often left blind after both eyes are surgically removed. Cells with the genetic mutation that leads to retinoblastoma have a specific marker, so Angel Carcaboso at the Sant Joan de Déu Research Institute in Barcelona and his team engineered a virus to only replicate in the presence of that marker. That allows the virus to only affect the cancerous cells, and leave the surrounding tissue intact. In animals, the team showed that the virus stayed in the eye into which it was injected and that the side effects of the virus were mild and reversible. They also confirmed the virus’s tumour-killing capabilities in human cells in the lab. The team then tested the treatment in two children who were both 2 years old and were candidates for eye removal surgery. Though they saw promising effects, including small tumours diminishing or disappearing, both children ultimately had to undergo eye removal surgery.

1-23-19 A CRISPR gene drive for mice is one step closer to reality
The genetic tool might one day help control invasive wild rodents. Scientists are getting closer to creating a genetic pest-control measure against rodents. Female mice engineered to carry a genetic cut-and-paste machine called a gene drive may be able to pass a particular version of one gene on to more than 80 percent of their offspring, researchers report January 23 in Nature. That rate would beat the usual 50 percent chance of handing down a gene variant, first reported in 1865 by Gregor Mendel from his studies of peas. “What we’ve done is engineered a gene that can be inherited more frequently than it would be by normal Mendelian inheritance,” says Kimberly Cooper, a developmental geneticist at the University of California, San Diego. “My graduate student likes to call it ‘cheating Mendel.’” Such engineered genetic cheats have been proposed to wipe out disease-carrying mosquitoes and invasive species by targeting genes involved in reproduction (SN: 12/12/15, p. 16). Gene drives might also be used to prevent pests from carrying diseases, such as malaria (SN: 12/26/15, p. 6). Researchers have made successful gene drives in laboratory experiments in mosquitoes, fruit flies and yeast. But no one has yet built one that works in a mammal. And Cooper isn’t claiming to have done so either. By definition, a gene drive must cheat Mendelian inheritance rules over multiple generations, spreading itself to an entire population. Cooper’s group has produced one generation of genetic cheater mice, but hasn’t yet tracked the gene drive’s spread through multiple generations.

1-23-19 The last Neanderthals may have died out much earlier than we thought
We used to think the Iberian Peninsula was the Neanderthals’ final stronghold. It appeared that our species somehow failed to find a way into the region until about 35,000 years ago, leaving the last remaining Neanderthal population untouched. But stone tools from a cave in southern Spain may now sink that idea once and for all. The tools suggest our species actually reached southern Spain 43,000 years ago, meaning Neanderthals may have vanished from Iberia soon after – at the same time that they disappeared from the rest of Europe. Neanderthals lived in Europe for hundreds of thousands of years. Then just before 43,000 years ago, our species – Homo sapiens – arrived in the continent and quickly occupied the entire landmass, probably contributing to the disappearance of the Neanderthals. But there is one corner of the continent where researchers have struggled to apply this simple model. It has proved difficult to find evidence that H. sapiens arrived in the Iberian Peninsula before about 35,000 years ago. What’s more, some researchers say they have found stone tools that indicate Neanderthals were still living in Iberia thousands of years after they had vanished from the rest of Europe. At some sites, such as Gorham’s Cave in Gibraltar, there are claims that Neanderthals survived until 32,000 years ago. They say Neanderthals clung on so long there because there were no H. sapiens to compete with. But Francisco Jime´nez-Espejo at the Japan Agency for Marine-Earth Science and Technology, and his colleagues think that idea no longer stands after they reanalysed stone tools found at Bajondilla Cave near Malaga. They say they can see the moment when Neanderthal-style tools give way to distinctly human-style tools. New radiocarbon dates from the cave suggest this transition happened 43,000 years ago – which would imply our species arrived in southern Iberia at the same time it reached other regions of Europe.

1-23-19 Human or hybrid? The big debate over what a species really is
Humans once mated with Neanderthals so are we hybrids? How we see ourselves and the rest of nature is changing, raising the question of whether species even exist. BIOLOGY is a messy business. Witness these sage words: “It is really laughable to see what different ideas are prominent in various naturalists minds, when they speak of ‘species’… It all comes, I believe, from trying to define the undefinable.” Strong stuff. And from a surprising source. Charles Darwin wrote those lines in a letter to fellow naturalist Joseph Hooker, just three years before the publication of On the Origin of Species. Darwin clearly had a problem with the word to which his name is now so intimately linked. It turns out he is not alone. Today, almost 160 years after he revolutionised biology, how to define a species is more problematic than ever. You probably learned that a species is a group of individuals that can breed to produce fertile offspring, but this is just one of dozens of competing definitions. The lack of consensus on what a species is has big implications for how we think about the natural world and for our efforts to conserve it. But the problems go even deeper. Recent revelations about interbreeding between what some regard as separate species of ancient humans have left many of us wondering: who are “we”, who are “they” and are we actually all one and the same? In other words, how we define a species has become a question at the very heart of human identity. Perhaps it is time to rethink the whole concept. The idea that the living world is divided into distinct species has deep roots. Frank Zachos at the Natural History Museum Vienna, Austria, suspects it predates the written word. He thinks that even livestock farmers living 10,000 years ago understood it. “Cows produce cows,” he says. “Dogs produce dogs.” Early farmers would have noticed this and seen it as reflecting some underlying order to the natural world.

1-23-19 The cerebellum may do a lot more than just coordinate movement
Connections from the ‘little brain’ are linked to social behavior, a study in mice finds. Its name means “little brain” in Latin, but the cerebellum is anything but. The fist-sized orb at the back of the brain has an outsized role in social interactions, a study in mice suggests. Once thought to be a relatively simple brain structure that had only one job, coordinating movement, the cerebellum is gaining recognition for being an important mover and shaker in the brain. Early clinical observations of people with movement disorders pigeonholed the cerebellum, says neuroscientist Kamran Khodakhah of Albert Einstein College of Medicine in New York City. But the “cerebellum has more than half of the neurons in your entire brain,” he says. “It never made sense that the only thing it confines itself to do is motor coordination.” Khodakhah’s new results on social behavior, described in the Jan. 18 Science, expand that view, and add to other work on the cerebellum’s role in memory, language and emotions. The results also offer clues to disorders such as autism and schizophrenia, both of which have been linked to an abnormal cerebellum. By finding a connection between the cerebellum and a part of the brain involved in social behavior, Khodakhah and his colleagues “solve an important gap in our understanding of the circuitry underlying disorders such as autism and schizophrenia,” says pediatric neurologist and developmental biologist Mustafa Sahin of Boston Children’s Hospital. “We’ve known for a while that the cerebellum is involved in these disorders, but we really haven’t been able to connect it to other regions directly.”

1-23-19 Africans may have crossed the Strait of Gibraltar 4000 years ago
Ancient people from sub-Saharan Africa may have crossed the Strait of Gibraltar into current-day Spain 1300 years earlier than we thought. A genetic analysis of human samples is the first evidence of such a migration in prehistoric times. “We are finding that the Strait of Gibraltar was not a barrier for human contact, migration or gene flow between Africa and Spain,” says Gloria Maria Gonzalez Fortes at the University of Ferrara in Italy. Previous research suggested that African genes flowed to Spain and Portugal during the Islamic occupation of Spain, which started in the 8th century and lasted about 800 years. “We found that it may be from a time much earlier than that,” says Gonzalez Fortes. She and her team analysed the DNA from 17 ancient people found on the Iberian Peninsula, from the south of Spain to the north of Portugal, carbon dated to 3000 to 4500 years old. They compared their mitochondrial DNA to archaeological samples from South Africa. Mitochondrial DNA is inherited through maternal genes, and doesn’t combine with paternal DNA, so it can be traced through the generations. “My mitochondrial DNA is identical to my mother’s, and hers is identical to her mother,” she says. They found similarities between the samples from Iberia and Africa, with more African genetic markers in the Spanish samples. This fits with the archaeological record, which shows similarities in tools and pottery decoration made by North African people and those who populated Andalusia in southern Spain.

1-23-19 Exclusive: 600-million-year old blobs are earliest animals ever found
Fossils in China suggest that that some of the first animals in existence may have been carnivorous comb jellies similar to some species that still exist today. MOVE over, Dickinsonia. This 558-million-year-old creature was named the earliest known animal last year, but New Scientist can now exclusively reveal one that existed even earlier – by more than 40 million years. This previously unknown animal comes from 600-million-year-old rocks in China and doesn’t have a name yet. While Dickinsonia was an Ediacaran – a primitive group of organisms that went extinct about 541 million years ago – the unnamed animal seems to have belonged to a group of animals that still exists today: comb jellies. It was discovered by Zhenbing She at the China University of Geosciences, Wuhan. “The origin and earliest evolution of animals is a fascinating question that has puzzled scientists for many decades,” said She as he unveiled his findings at a meeting of the Geological Society of London in London last week. The fossils were found in a drill core taken from the Doushantuo Formation in southern China. These beds have already yielded exquisitely preserved fossils from as far back as 631 million years ago. These mysterious fossils are only visible through microscopes, and may be algal cells, developing animal embryos or something else entirely. Among these rocks, She’s team has found fossils visible to the naked eye, measuring about 0.7 millimetres across. The first clue to their identity was their jellyfish-like shape. Microscopic analysis revealed what appear to be tentacles, muscle tissue, nerve cells, gonads, mucous layers and clusters of hairlike-structures called cilia.

1-22-19 Common vaccine may protect children from developing type 1 diabetes
Rotavirus vaccine may protect children from developing type 1 diabetes. In Australia, the vaccine for rotavirus – the most common cause of severe diarrhoea in young children – was added to routine early-childhood immunisations in 2007. Kirsten Perrett at the University of Melbourne in Australia and her colleagues compared the rates of diabetes in the 8 years before and after the introduction of the rotavirus vaccine. They found a 14 per cent drop in type 1 diabetes in children age 0 to 4, but no change in children 5 to 14 years old. Perrett says that is likely because the children in the study under age 5 were born after the introduction of the vaccine, which must be given before exposure to the virus to have any protective effect. Rotavirus infects pancreas cells by hijacking a natural receptor on their surface, which leads to cell death. The vaccine stops this process in insulin-producing cells, which may be why it is effective against diabetes as well. Perrett and her team our now looking into links between type 1 diabetes and reduction in pancreas size associated with the disease.

1-21-19 We’ve discovered a new type of blood vessel in our bones
It’s time to rewrite the anatomy books: a new kind of blood vessel has been discovered in our bones. These previously unknown vessels cross from the bones’ surface to their internal cavity and may shed light on bone diseases, such as osteoporosis, and conditions involving the immune system. “It’s totally crazy there are still things to find out about human anatomy – we have discovered blood vessels in a new place that we didn’t know about before,” says Matthias Gunzer of University Duisburg-Essen in Germany. Human anatomy is not usually seen as an ongoing area of major discoveries, but even today new tissues or organs occasionally come to light. Gunzer’s team made their finding by using chemicals on a mouse bone to make it transparent. They could then see tiny red blood vessels crossing the bone shaft. In the animal’s lower leg bone – the size of a match-stick – they saw about a thousand of these capillaries, which they dubbed trans-cortical vessels. Beforehand, we knew of just a few blood vessels entering the bone either at its ends or half-way along. The newly found capillaries cover the whole bone, making up most of its blood supply.People also have similar trans-cortical vessels, as the team spotted them in small pieces of human thigh bone too. There are other kinds of blood vessels feeding human bones, so trans-cortical vessels may make up less of their total circulation – but no one has yet counted them in a whole human bone. Marrow inside bones is where immune cells are made, and in mice the trans-cortical vessels have turned out to be a key route for immune cells to exit – the same might go for people, says Gunzer.

1-21-19 Creation of gene-edited babies in China may have been illegal
A preliminary investigation into the creation of gene-edited babies in China has concluded that Chinese researcher He Jiankui “illegally conducted the research in the pursuit of personal fame and gain”, reports the Xinhua state news agency. An investigating team set up by the Health Commission of China in southern Guangdong province said on Monday that He had avoided supervision, raised funds and organised researchers on his own to carry out the work. The case has been referred to the ministry of public security, which investigates suspected crimes. The report stops short of confirming that the genome-edited babies – created using the CRISPR method – really do exist. Xinhua refers to “the claimed ‘genetically edited babies’”, so we still have no independent confirmation beyond what He has said. However, many biologists think the serious flaws in the work suggested by the details He has revealed have the ring of truth. Robin Lovell-Badge of the Francis Crick Institute in London – who chaired the meeting where He made his claims and spoke to him on several occasions – is one who believes that the work is real. “If he was going to make this up, surely he would have made it up much better than this,” he said earlier this month. The Xinhua report also states that gene-editing human embryos for the purpose of reproduction “is banned by Chinese law”, which may have serious repercussions for He. Most previous reports have suggested this was merely a guideline, rather than a law. According to Lovell-Badge, He was fully aware of the guideline – or law – and chose to ignore it. (Webmaster's comment: Like Galileo the people of the world are against this courageous pioneer!)

1-21-19 He Jiankui: China condemns 'baby gene editing' scientist
China says the scientist who claims to have created the world's first genetically edited babies last year acted illegally and in pursuit of fame and fortune, state media report. He Jiankui's claim to have altered twin girls' genes so they could not get HIV was met with scepticism and outrage. Investigators say the researcher faces serious punishment after acting on his own and forging ethical review papers. Professor He, who is reportedly under house arrest, has defended his work. In November, he told a genome summit in Hong Kong he was "proud" of his gene-editing work, a practice which is banned in most countries, including China. His announcement was met with condemnation from hundreds of Chinese and international scientists, who said any application of gene editing on human embryos for reproductive purposes was unethical. Prof He's claims had not been verified, but investigators confirmed on Monday that his work had resulted in the birth of twin babies, and that another woman was currently pregnant. Investigators from Guangdong provincial government said the doctor had raised his own funds, deliberately avoiding oversight. He had also allegedly used technology of an uncertain safety level in order to carry out human embryo gene editing. nvestigators confirmed Prof He had recruited eight couples to participate in his experiment, resulting in two pregnancies. They said baby twins nicknamed Lulu and Nana were born in November, and are under medical supervision. Since Prof He's announcement of his experiment, he is said to have been placed under house arrest in Shenzhen. (Webmaster's comment: The church of world opinion will burn this man at the stake but he is a hero like Galileo!)

1-21-19 Probability helps zebrafish stay in schools when faced with predators
Zebrafish are exceptionally good synchronised swimmers, forming tight schools that contain hundreds of individuals. Physicists have shown how the fish stay together even as they swim faster to avoid a predator – and they do so by subconsciously performing the kind of weighted averages calculation familiar to high-school mathematics students. Small fishes tend to swim in schools. Sticking together decreases the risk of any individual fish being killed by predators, and biologists say a school of fish can have more foraging success because many eyes are better than two when it comes to searching for food. Scientists have built mathematical models to understand how fish manage to swim so closely to dozens of others without colliding. They found that in order to maintain the schools’ structure, every fish keeps tabs on what many of its peers are doing – their speed, orientation, and any changes in either of these. Gonzalo de Polavieja at the Champalimaud Centre for the Unknown in Portugal wanted to know if these rules still applied when the school comes under attack from a predator and the fish must swim faster. With his colleagues, de Polavieja tracked the movement and speed of over 200 zebrafish swimming in groups in fishtanks in their lab. Through modelling, they found the earlier mathematical models no longer apply when the fish move quickly – at more than three body lengths per second. At these higher speeds, the fish collect the bare minimum information they need to avoid collisions and synchronise their swimming with others. The model shows each fish considers the position, speed and direction of just five neighbours on average. Even then, not all of them matter equally. The movement and speed of neighbours that swim faster or are closer have the biggest impact on the direction and speed of any individual fish.

1-19-19 It's not always in your head
How emotions are felt throughout your body. verything we sense in our external and internal worlds has a distinct subjective quality. A blasting outburst of rage feels different than a lover's tender kiss on the cheek. Even routine acts, such as reading a book or trying to recall a childhood friend's name, feel remarkably different. These and countless other feelings fill the wavelengths of our consciousness and drive our daily pursuits, helping us to navigate the world. We seek things that make us feel delight and enjoyment, and steer clear of things that cause stress or suffering, unless we expect pleasure to follow the pain. It is puzzling, however, how these external and internal pieces of information are organized into inner, subjective states. There is a strong intuition that our conscious self resides inside the body, specifically in our head. This might be because several of our sensory organs — eyes, ears, nose, taste buds — are located in the head. The psychologists Christina Starmans, now at the University of Toronto, and Paul Bloom at Yale University in Connecticut found that, when prompted, both adults and children locate a human's self inside the head, but when shown pictures of aliens whose eyes are elsewhere, such as on the stomach, people mostly point toward the eyes rather than the eyeless head as the location of the self. Body and mind are not separable. Rather, they operate in tandem, providing the building blocks of our mental lives. For example, even mild bodily infections make us feel confused and fatigued, whereas a good, exhausting bout of exercise can lift our mood and make us feel, at times, euphoric. My colleagues and I recently took this idea of embodied consciousness further and looked into mapping the "cartography" of conscious feelings onto the body (building on our earlier work on the bodily basis of emotions). We first generated a list of 100 common feelings such as such as seeing, breathing, hunger, pleasure, and so forth, and asked participants to locate these states on their bodies by coloring in the regions of a human shape where each sensation was felt. We also gathered basic information regarding each feeling, such as how pleasant these states were, how often they are experienced, and how similar different states feel when experienced.

1-18-19 Cancer deaths on the decline in U.S.
The U.S. cancer death rate plummeted by 27 percent from 1991 to 2016—a decline that amounts to as many as 2.6 million lives saved. That’s the encouraging conclusion of a new report by the American Cancer Society, which examined data from sources including the National Center for Health Statistics and the National Program of Cancer Registries. Researchers noted that the cancer death rate climbed steadily for most of the 20th century, largely because of men dying from lung cancer. But after peaking in 1991, the rate has dropped 1.5 percent a year. The drop-off is mostly due to anti-smoking campaigns and advances in detection and treatment of cancers. It’s not all good news, though. The report estimates 1.8 million new cancer cases this year and more than 600,000 deaths. Prostate cancer deaths are no longer falling, and obesity-related cancer deaths are rising—a trend researchers worry could signal larger problems ahead. “We are probably only seeing the tip of the iceberg regarding the influence of the obesity epidemic on cancer rates,” lead author Rebecca Siegel tells The Wall Street Journal. Another cause for concern is that among adults under age 55 the incidence of colorectal cancer has increased almost 2 percent a year since the mid-1990s. Some scientists think obesity is to blame, but others suspect “something else is going on,” says Siegel. “Everyone is scrambling to try to figure it out.”

1-18-19 Monogamy in the genes?
Scientists believe they now know why some animals stay with their mates and others don’t: It’s all in the genes. A research team at the University of Texas at Austin identified five monogamous species, then compared them with more promiscuous close relatives: California mice vs. deer mice, mimic poison frogs vs. strawberry poison frogs, and so on. (Monogamy was defined as staying with the mate and jointly raising offspring for at least one mating season.) After analyzing the animals’ brain tissue, the researchers discovered that males that stayed loyal to their mates bore a common genetic formula: specifically, 24 genes whose activity is consistently ramped up or dialed down. It’s not yet known whether human genes behave in a similar way, and thus whether there could one day be a genetic test for human monogamy. “There are differences among individuals and a test may have to be very individualized to be effective,” lead author Rebecca Young tells The Guardian (U.K.). “Is it impossible? I’d never say that.”

1-17-19 New ways to image and control nerve cells could unlock brain mysteries
Using the methods to target neurons in mice and fruit fly brains may lead to insights. Using laser light, ballooning tissue and innovative genetic tricks, scientists are starting to force brains to give up their secrets. By mixing and matching powerful advances in microscopy and cell biology, researchers have imaged intricate details of individual nerve cells in fruit flies and mice, and even controlled small groups of nerve cells in living mice. The techniques, published in two new studies, represent big steps forward for understanding how the brain operates, says molecular neuroscientist Hongkui Zeng of the Allen Institute for Brain Science in Seattle. “Without this kind of technology, we were only able to look at the soup level,” in which diverse nerve cells, or neurons, are grouped and analyzed together, she says. But the new studies show that nerve cells can be studied individually. That zoomed-in approach will begin to uncover the tremendous diversity that’s known to exist among cells, says Zeng, who was not involved in the research. “That is where the field is going. It’s very exciting to see that technologies are now enabling us to do that,” she says. These novel abilities came from multiple tools. At Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va., physicist Eric Betzig and his colleagues had developed a powerful microscope that can quickly peer deep into layers of brain tissue. Called a lattice light sheet microscope, the rig sweeps a thin sheet of laser light down through the brain, revealing cells’ structures. But like any microscope, it hits a wall when structures get really small, unable to resolve the most minute aspects of the scene.

1-17-19 Silencing brain cells in mice can make them no longer care about pain
Pain doesn’t have to be painful. That’s the conclusion of a study that identified a set of nerve cells that add emotional content to pain signals in the brains of mice. The discovery could lead to new treatments for chronic pain that ease patients’ suffering without impairing their ability to sense injuries. Pain receptors throughout the body detect painful stimuli and send signals via nerves to the brain. But according to Grégory Scherrer at Stanford University, California, these signals don’t have any emotional value until they reach the amygdala, a brain region that deals with emotions. In other words, the unpleasantness of pain is added by the amygdala and is separate to the information that comes from pain receptors. To see how pain signals are processed in the amygdala, Scherrer and his colleagues added a gene to this region of the brain to make the cells produce a marker that lights up when they are active. The team then identified a group of cells that respond specifically to painful stimuli such as a pin prick or heat. Next, they silenced these cells by engineering them to express receptors for a drug that turns down their activity. The mice could still detect painful stimuli and withdraw from them, just as you would withdraw your hand if you touched a hot stove. But they didn’t adopt defensive behaviours, lick their wounds or try to escape as could be normally expected. “It’s as if they don’t care about pain any more, even though they can detect it,” says Scherrer. The neural circuits for pain have a high degree of similarity across species, so it’s likely that a similar set of cells can be found in humans, says Scherrer. “We’re hoping it’s a new avenue to treat pain,” he says.

1-17-19 Overdose deaths tied to antianxiety drugs like Xanax continue to rise
Many fatalities involving benzodiazepines also involve opioids. As public health officials tackle opioid addiction and overdoses, another class of prescription drugs has been contributing to a growing number of deaths across the United States. Benzodiazepines, such as Valium and Xanax, are commonly prescribed for anxiety and insomnia. The drugs are also highly addictive and can be fatal, especially when combined with alcohol or opioids. In the latest sign of the drug’s impact, the number of overdose deaths involving “benzos” rose from 0.54 per 100,000 in 1999 to 5.02 per 100,000 in 2017 among women aged 30 to 64, researchers report January 11 in the Morbidity and Mortality Weekly Report. That’s a spike of 830 percent, surpassed only by increases seen in overdose deaths involving synthetic opioids or heroin. Overall, there were 10,684 overdose deaths involving benzodiazepines in the United States in 2016, according to the National Institute on Drug Abuse. In 1999, the total was 1,135. Benzodiazepines have a sedating effect, and are particularly dangerous when used with other drugs that slow breathing, such as opioids and alcohol. In combination, the substances can “cause people to fall asleep and essentially never wake up again,” says Anna Lembke, an addiction psychiatrist at Stanford University School of Medicine. Benzos and opioids are often prescribed together, and opioids contribute to 75 percent of overdose deaths involving benzos. The rising number of deaths involving benzos hasn’t stopped the flow of prescriptions. The number of U.S. adults who filled a prescription for benzos rose from 8.1 million in 1996 to 13.5 million in 2013, a jump of 67 percent, a study in the American Journal of Public Health in 2016 found. The quantity of benzos acquired more than tripled over the same time.

1-17-19 World's coffee under threat, say experts
The first full assessment of risks to the world's coffee plants shows that 60% of 124 known species are on the edge of extinction. More than 100 types of coffee tree grow naturally in forests, including two used for the coffee we drink. Scientists say the figure is "worrying", as wild coffee is critical for sustaining the global coffee crop. About one in five of the world's plants is threatened with extinction, and the 60% figure is an "extremely high" one. "If it wasn't for wild species we wouldn't have as much coffee to drink in the world today," said Dr Aaron Davis of the Royal Botanic Gardens, Kew. "Because if you look at the history of coffee cultivation, we have used wild species to make the coffee crop sustainable." Research published in the journal, Science Advances, found conservation measures were "inadequate" for wild coffees, including those considered "critical" for long-term global coffee production. The study found that 75 wild coffee species are considered threatened with extinction, 35 are not threatened and too little is known about the remaining 14 to make any judgement. Furthermore, it was found that 28% of wild coffee species grow outside protected areas and only about half are preserved in seed banks. A second study, in Global Change Biology, found that wild Arabica coffee can be classed as threatened under official (IUCN Red List) rankings, when climate change projections are taken into account. Its natural population is likely to shrink by up to 50% or more by 2088 because of climate change alone, according to the research. Wild Arabica is used to supply seeds for coffee farming and also as a harvested crop in its own right. Ethiopia is the home of Arabica coffee, where it grows naturally in upland rainforests.

1-17-19 Rational thinking is saving antibiotics – it could work on Brexit too
The turning of the tide in the fight against bacterial resistance to antibiotics shows the benefits of clear thinking and leadership, and it could work for Brexit too. With politicians unable to agree what to do next, and time running out to agree an amicable split from the European Union before 29 March, the UK has lurched one step closer to a “no-deal” Brexit. Such a scenario, welcomed by some as a clean break from the trading bloc, is seen as an apocalyptic outcome by others. Whatever your view, medics are warning that lives could be put at risk if a no-deal exit leads to shortages of medicines and essential equipment. But quietly, away from the fire and fury of daily politics, another potential apocalypse is fading from view. For decades, we have been warned about the rise of antibiotic resistance, in which deadly bacteria evolve to become immune to the drugs designed to kill them. This has the potential to be far worse than a bad Brexit, putting millions at risk around the world – and even beyond, as worries grow about its effects on astronauts. It is easy to forget how much stability working antibiotics bring to our lives, and how dire their failure would be. Thankfully, the tide is turning. New drugs are being developed and, more importantly, efforts are under way to bring them into use. The unique, unprofitable model of antibiotic drugs being used sparingly, for brief periods, has created a market failure that has been leading us to potential doom. Now, governments, led by the UK, are stepping in with new programmes to help keep their citizens safe. It won’t be the end of the battle, but it is the beginning of a fightback. It just goes to show what can be achieved with strong leadership, a proper understanding of risk mitigation, and the will to collaborate across borders. There are lessons to be learned here. Apocalypses are avoidable, even self-inflicted ones.

1-16-19 Why doing more exercise won’t help you burn more calories
Forget the idea that to lose weight you just need to work off more calories than you consume. The truth is far weirder. A SIMPLE calculation lies at the heart of a lot of mainstream weight loss advice. If calories out exceed calories in, you will lose weight. It is why both exercise and diet are said to be key to staying trim, and why many of us feel we can make amends for overindulging by joining the gym or dusting off our running shoes. But if you have ever increased how much exercise you do and found it did little to shed the pounds, you have probably had an inkling that the sums don’t add up. Despite tipping the balance in favour of calories out, the scales don’t budge. This is the so-called exercise paradox. Until recently, it has been explained away by the logic that exercise leaves people hungry so they eat more. It now turns out something weirder is going on. Working out a lot doesn’t appear to burn more calories than doing a little. In fact, going mad in the gym doesn’t seem to burn any more calories than moderate activity a few days a week and taking the stairs, for instance. Researchers are scratching their heads as to how to reconcile this. And while it might be bad news for those who had hoped to run off those festive dinners, there is a flip side. Those who exercise intensively through a sense of guilt or obligation might be happier, and possibly wealthier, taking it easier. Some of the biggest clues that something was up with the exercise and weight loss equation lie far from the gym, on the plains of Tanzania. Here, the Hadza people live as we all once did, as hunter-gatherers. The men walk about 10 kilometres each day, stalking game with bows and arrows, while women spend hours on the move, digging for wild tubers and picking berries.

1-16-19 Engineered bacteria could mop up toxic ammonia in the human gut
Supplements of genetically modified bacteria could be used to treat liver and bowel diseases by mopping up toxins inside the gut. The approach, of tweaking bacteria so they turn harmful ammonia into a safe compound, has shown promise in animal tests and in healthy human volunteers. Many of us now take daily doses of probiotics to help top up good bacteria in the gut , although it’s unclear how much good they really do. But genetically altering bacteria to give them new abilities could take things to the next level, says Caroline Kurtz of manufacturer Synlogic, a biotech firm based in Cambridge, Massachusetts. “These are living medicines that are able to sense their environment and perform a function for a patient.” Ammonia is made in the gut as a by-product of food digestion; it normally goes to the liver to be dealt with, but cirrhosis of the liver or certain metabolic disorders can lead to a build-up of ammonia in the blood, causing seizures or death. Synlogic has changed the genes of a bacterium called Escherichia coli Nissle – which in unmodified form is already sold as a probiotic – to boost its uptake of ammonia. The bacteria turn the toxin into a compound called L-arginine, an amino acid present in our diet. Daily doses of the bacteria improved survival in mice genetically engineered to have one of the ammonia-raising metabolic disorders. And when healthy humans took the bacteria in a drink for two weeks, blood tests showed the bacteria were working as intended. For safety reasons, the microbes were also genetically changed so they could not reproduce. Two weeks after the trial ended, there was no more DNA from the microbes in the volunteers’ faeces. That means patients would have to take supplements long-term, but there’s less risk. A trial has started in people with cirrhosis.

1-16-19 Bacterial compounds may be as good as DEET at repelling mosquitoes
The bacterium that produces these molecules lives in symbiosis with soil nematodes. Molecules made by bacteria keep mosquitoes at bay. The compounds are a newfound potential stand-in for DEET, a ubiquitous chemical used in most commercially available mosquito repellents in the United States. In lab tests, the molecules were as effective as DEET in stopping Aedes aegypti mosquitos, which can carry Zika, dengue and yellow fever, from snacking on artificial blood, researchers report January 16 in Science Advances. Tests suggest the compounds also deter two other mosquito species: Anopheles gambiae, a major malaria carrier, and Culex pipiens, which can carry the West Nile virus. Though DEET is considered safe for human use and effective against mosquitoes, it doesn’t hurt to have more lines of defense against the disease-transmitting insects, says coauthor Susan Paskewitz, an entomologist at the University of Wisconsin–Madison. The molecules in question are metabolic by-products of Xenorhabdus budapestensis, a bacterium that has a symbiotic relationship with a species of soil nematode. When the nematode finds an insect host such as a caterpillar, it burrows in and defecates the bacteria into its host’s bloodstream. The bacteria weaken the host’s immune system and turn its insides to mush — a sort of “bacteria-insect milkshake” — which rapidly kills the host, says Adler Dillman, a nematologist at the University of California, Riverside who wasn’t part of the study. Scientists have found other insect-killing compounds made by other bacteria in the same genus, but this is the first time bacterial compounds have been shown to ward off adult mosquitoes.

1-16-19 An ancient child from East Asia grew teeth like a modern human
The youngster’s species is unknown for now. An ancient child with a mysterious evolutionary background represents the oldest known case of humanlike tooth growth in East Asia, researchers say. The child’s fossilized upper jaw contains seven teeth that were in the process of developing when the roughly 6½-year-old youngster died at least 104,000 years ago and possibly more than 200,000 years ago. Using X-rays to examine the teeth’s internal structure revealed that the first molar, which typically sprouts through the gums at around age 6 in kids today, had erupted a few months before death. The root of that tooth was about three-quarters complete, similar to the pace of development in modern human children. Other tooth roots found in the fossil grew more rapidly than those of modern youngsters. But the ancient child’s overall dental growth and development falls within the range observed among kids today, paleoanthropologist Song Xing of the Chinese Academy of Sciences in Beijing and her colleagues report online January 16 in Science Advances. That humanlike rate of dental development suggests that the youngster belonged to an East Asian Homo population with a relatively long life span and an extended period of child care, the researchers speculate. Those characteristics are associated with present-day humans’ lengthy period of tooth growth. But it’s hard to know where the child’s remains, unearthed with other hominid fossils at a northern Chinese site called Xujiayao in the late 1970s, fit in human evolution.

1-16-19 The war against antibiotic resistance is finally turning in our favour
We are finally seeing progress in the battle against antibiotic resistance, but now we must make it profitable to develop new drugs. ANTIBIOTICS have changed what it means to be human. Few of us remember when bacterial infections from a wound, a bout of flu, sex or childbirth could kill anyone, at any time. This constant risk of death was just something we lived with. When antibiotics became common in the 1950s, that ended – and the drugs also opened a new frontier of surgery and therapy for other diseases. But the bad old days are returning as bacteria evolve to resist antibiotics. Just last week, news emerged of two women in the UK infected with resistant, or “super”, gonorrhoea. Thankfully they were cured, but others may not be so lucky. You have probably heard about this problem – New Scientist has been reporting on it for decades. After urgent alarms were sounded in 2015, governments and charities finally ploughed more money into drug discovery. These efforts are starting to bear fruit, but there is a larger problem – one of economics, not science. The issue is that pharma firms must recoup their investment in developing drugs, but antibiotics are the antithesis of a bestseller. They are taken for days or a few weeks, whereas diabetes or heart drugs are highly profitable because patients can use them for life. Plus, new antibiotics can’t compete with older, cheaper drugs that still work and are no longer patented. By the time resistance to the old antibiotics builds up and doctors must prescribe new, expensive ones, their patented life may be almost over, leaving little time for their owner to turn a profit. Novel drugs must also be kept in reserve or used sparingly, to stop bacteria building a resistance to them, too.

1-16-19 Type 2 diabetes may not be a lifelong condition
New evidence shows that weight loss can push the condition into remission, offering hope for patients, says Elizabeth Robertson. TYPE 2 diabetes has long been considered a progressive, lifelong condition, with significant risk of developing vascular complications. But ongoing research funded by Diabetes UK is changing that view, showing that remission of type 2 is possible for some people. The number of people in the UK living with diabetes is growing. Two key drivers are people living longer and significant weight gain. The Diabetes Remission Clinical Trial (DiRECT) aims to find out if weight loss can put type 2 diabetes into remission and keep it there. Participants receive a low-calorie liquid diet for between eight and 20 weeks. This is followed by support from a healthcare professional to reintroduce healthy food back into the diet and keep the extra weight off for the long term. The initial results, announced in December 2017, demonstrated that after 12 months, almost half the participants had achieved normal blood glucose levels without having taken any diabetes medication. As the trial continues, researchers are also exploring the psychosocial aspects of the intervention, including motivation, behavioural change and social support, and the biology behind the change. They have shown that weight loss of 10 to 15 kilograms is needed to shed excess fat in the liver and pancreas, triggering a return to normal insulin production. Further work is ongoing to understand why some people don’t achieve the same result despite significant weight loss. The intervention is also affordable. A recent economic study found that, in its first year, it would cost around £1000 per person. NHS England has announced plans to roll out a pilot intervention for 5000 people.

1-16-19 Robot version of our distant ancestor hints at how we learned to walk
A robotic version of a creature that lived about 290 million years ago may lead us to rethink an important evolutionary event in our past. It suggests animals with four legs could have gained advanced walking skills before they had fully turned their backs on life in water. Some reptiles and amphibians look superficially similar when they walk, because their legs are sprawled out on either side of the body. In detail, though, amphibians tend to move inefficiently with their legs held mostly horizontal and their bellies very close to the ground. Many reptiles, in contrast, hold their legs a little more vertically and raise their bellies further off the ground for a more energy efficient walking style. John Nyakatura at the Humboldt University of Berlin and his colleagues may have helped pin down when this change occurred. They have studied an ancient animal called Orobates that, in evolutionary terms, lies on a branch between the amphibians and the reptiles. It may even have had to return to water to lay its eggs as almost all amphibians still do, meaning it may not have been completely adapted to life on land. But even though Orobates may not have lived on land for its entire life, Nyakatura’s team suspects it actually walked like an energy efficient reptile. They reached this conclusion by taking advantage of the fact that we have near-complete fossils of the Orobates skeleton, and also fossilised footprints left by the animal. Using the shape of the skeleton and the pattern of the footprints as a guide, the researchers developed OroBOT. This is both a computer simulation and a physical robot modelled on the Orobates skeleton, and it is capable of generating a pattern of footprints identical to the fossilised trackways.

1-16-19 Long lost cities in the Amazon were once home to millions of people
We used to think the Amazon rainforest was virtually untouched, but it now seems to have been filled with sprawling settlements whose inhabitants shaped the land. THE Amazon rainforest is so vast that it boggles the imagination. A person could enter at its eastern edge, walk 3000 kilometres directly west and still not come out from under the vast canopy. This haven for about 10 per cent of the world’s species has long been regarded as wild and pristine, barely touched by humanity, offering a glimpse of the world as it was before humans spread to every continent and made a mess of things. It is painted in sharp contrast to the logged forests of Europe and the US. But it now seems this idea is completely wrong. Far from being untouched, we are coming to realise that the landscape and ecosystem of the Amazon has been shaped by humanity for thousands of years. Long before the arrival of Europeans in the Americas, the Amazon was inhabited, and not just by a handful of isolated tribes. A society of millions of people lived there, building vast earthworks and cultivating multitudes of plants and fish. We don’t fully understand why this flourishing society disappeared centuries ago, but their way of life could give us crucial clues to how humans and the rainforest could coexist and thrive together – even as Brazil’s new government threatens to destroy it. Some of the first Europeans to explore the Amazon in the 1500s reported cities, roads and cultivated fields. The Dominican friar Gaspar de Carvajal chronicled an expedition in the early 1540s, in which he claimed to have seen sprawling towns and large monuments. But later visitors found no such thing.

1-15-19 A new 3-D printed ‘sponge’ sops up excess chemo drugs
The device prevented a liver cancer drug from spreading through pigs’ bodies, curbing toxicity. Bringing the filtering abilities of a fuel cell into the blood vessels of living organisms, a new device could cut down on toxic effects of cancer treatment. At the heart of this approach — recently tested in pigs — is a tiny, cylindrical “sponge” created by 3-D printing. Wedged inside a vein near a tumor being treated with chemotherapy, the sponge could absorb excess drug before it spreads through the body — thus lessening chemotherapy’s harmful side effects, including vomiting, immune suppression or even heart failure. A human study could launch “in a couple of years, if all the stars are aligned,” says Steve Hetts, a neuroradiologist at the University of California, San Francisco who came up with the drug-capture concept. He worked with engineers at UC Berkeley and elsewhere to create and test prototypes. A test of the most recent prototype showed that the absorber captured nearly two-thirds of a common chemotherapy drug infused into a nearby vein, without triggering blood clots or other obvious problems in the pig, Hetts and his colleagues report January 9 in ACS Central Science. The study addresses a major need, says Eleni Liapi, a radiologist at Johns Hopkins University School of Medicine not involved with the new work. Existing methods for controlling chemotherapy delivery do not fully block drug escape, she notes. “A technological advancement to reduce unwanted circulating drug is always welcome.”

1-15-19 Call for more transparency over ‘add-on’ fertility treatments
Clinics offering fertility treatment must be more transparent about the effectiveness and costs of “optional extras”, the UK’s fertility regulator has said. The Human Fertilisation and Embryology Authority says there is “no conclusive evidence” that any so-called add-ons offered with fertility treatment increase the chance of pregnancy or live birth. The HFEA has signed a consensus statement alongside 10 other fertility bodies saying that a failure to provide evidence-based treatment poses a significant risk to patient trust. According to the HFEA’s most recent national fertility patient survey, 74 per cent of patients receiving treatment over the last two years had at least one type of add-on. The most common add-ons include endometrial scratching, embryo glue, and the use of an embryoscope to monitor cell division. The HFEA rates 11 add-ons using a traffic light system. The green rating is reserved for procedures or techniques that have been shown to be effective and safe by at least one good-quality, randomised clinical trial. None of the 11 treatments have received a green rating. “Fertility treatment add-ons are being offered to more patients by clinics and we know many patients are asking for these add-ons and paying for them if they have private treatment,” says Sally Cheshire, of the HFEA. “It’s crucial that clinics are transparent about the add-on treatments they offer, including the potential costs, to ensure patients know exactly whether they are likely to increase their chance of having a baby.”

1-15-19 Teachers are scanning students’ brains to check they are concentrating
Are you concentrating? Some teachers are checking whether their students are paying attention by using headbands that read brain signals. Focus headbands, made by BrainCo in Massachusetts, were used in a recent trial with 10,000 school children aged between 10 and 17 in China. Over 21 days, students wore the headsets during class and teachers could monitor their average attention levels using an app. Lights on the front of the headsets also show different colours for distinct attention levels – flagging to teachers when a student might be daydreaming. The device can help teachers identify students who may need special assistance and pitch their lessons right, says Bicheng Han, founder of BrainCo. However, aside from the potential privacy issues around monitoring students’ brain activity, some are expressing concern over the device’s effectiveness. The Focus headband uses electroencephalography (EEG) sensors to detect changes in brain waves when the wearer is highly engaged in a task. Typically, the brain’s high-frequency beta waves are increased when we are focused, and the low-frequency alpha and theta waves are more excited when we are relaxed. The patterns vary from person to person, so Focus determines each user’s maximum attention level via a series of mental tasks. Students who participated in the experiments also had to play a smartphone game every day at home for 25 minutes aimed at increasing their ability to concentrate. The more they concentrated, the further they progressed in the game.

1-14-19 A child’s mix of gut bacteria may determine if they get allergies
A species of gut bacteria may be responsible for preventing allergies in children. Allergies have become much more common in industrialised countries since the mid-20th century, but it’s still not clear why. Some evidence points to the microbiome – the community of bacteria that live inside our bodies – as a possible factor. Children whose mothers take probiotic supplements seem to have a lower risk of allergies, while those born by caesarean section, which affects the acquisition of bacteria in the gut, may have a higher risk. Cathryn Nagler at the University of Chicago and colleagues found in an earlier study that children with a cow’s milk allergy have markedly different bacteria in their gut than healthy children. To see if those differences contribute to the development of allergies, they took faecal samples from babies with and without cow’s milk allergies and transplanted them into mice that lacked gut bacteria. Mice without gut bacteria and mice that received bacteria from children with allergies had anaphylactic reactions when exposed to cow’s milk for the first time, but mice that received bacteria from healthy children did not. That tells us that a certain population of bacteria is needed to prevent allergies, says Nagler. By combining data on the bacterial populations and patterns of gene expression in the intestine, the team discovered that one particular species, Anaerostipes caccae, appears to be a protective factor. If this species alone is transplanted into germ-free mice, they do not suffer allergic reactions to cow’s milk. As evidence has accumulated regarding the microbiome’s role in health, there has been growing interest in faecal transplants as experimental therapies. However, Nagler doesn’t think they are a good idea.

1-14-19 Easing test anxiety boosts low-income students’ biology grades
Simple psychological tricks could boost confidence before STEM-subject exams. At a large Midwestern high school, almost 40 percent of low-income biology students were poised to fail the course. Instead, thanks to simple measures aimed at reducing test anxiety, that failure rate was halved. Psychological interventions that improve grades could ultimately help keep more low-income students in the sciences, says Christopher Rozek, a psychologist at Stanford University and lead author of the study, which appears online the week of January 14 in the Proceedings of the National Academy of Sciences. Low-income students are much less likely than high-income students to complete four years of high school science. That leads to those students being less likely, or unable, to major in science and math in college or to pursue related — often lucrative — careers in adulthood. One of the many factors underlying this achievement gap is low-income students’ internalized feelings of inadequacy in such fields, Rozek says. Those feelings often translate to high pretest anxiety and worse grades. In previous, smaller studies, researchers have shown that reducing performance anxiety can improve test scores. To scale up that work, Rozek and colleagues recruited 1,175 freshman biology students at a public high school in Illinois; 285 of those students came from a low socioeconomic background. At the school, slightly over half of low-income students fail their final biology exams compared with just 6 percent of high-income students. Rozek’s group investigated whether 10-minute-long reading and writing prompts before an exam could improve test performance.

1-12-19 Ovarian cancer AI can tell how aggressive a woman’s tumour is
Artificial intelligence is helping researchers spot aggressive forms of ovarian cancer. Yinyin Yuan and colleagues at the Institute of Cancer Research in London built an AI to look for differences in tumour cell shape. It analysed tissue sample images from 514 women with ovarian cancer and found that misshapen nuclei correspond to a more aggressive form of the disease with a survival rate of 15 per cent over five years. That compares with 53 per cent for the standard form. Human researchers are very good at looking at cells, but it is hard to quantify differences and the process takes a lot of time – hence the use of AI, says Yuan. However, the test so far is of limited use, says Kevin Elias at the Dana-Farber Cancer Institute in Boston. “It is one thing to tell me a patient is likely to have a poor outcome, but if you are unable to suggest an alternative treatment, it is not that useful,” he says. AI is increasingly used in cancer research to sift data for patterns that can help us in various ways, like tracking tumour evolution and improving diagnosis. Yuan and her team will next use AI to look at cancer that resists chemotherapy, to try to develop more targeted treatments.

1-12-19 Bacteria live in China’s thick smogs and may be making it even worse
Bacteria are feeding and multiplying in the severe smogs that regularly blanket Chinese cities. The microorganisms could pose a threat in themselves and may also change the composition of the haze. China’s capital Beijing is regularly smothered in a thick, toxic haze that forms as a result of coal burning, vehicle exhausts and other sources. It is worst in winter, when weather patterns trap pollution over the city. China has cracked down on emitters, and in 2018 emissions fell 12 per cent, but there is a long way left to go. Many other cities, like Delhi in India, have similarly severe air pollution. Western countries like the UK tend to have cleaner air but it is often still more polluted than is thought safe. The World Health Organization says, because it worsens the risk of episodes like heart attacks and strokes, which can prove fatal. Most of the focus on air pollution has looked at the chemicals that make up smog and how they interact. But Maosheng Yao at Peking University in Beijing, China, is one of several researchers who suspect there is another factor involved: microorganisms like bacteria. In a study published in 2016, Yao’s team showed that tiny clumps of bacteria were common during severe hazes in Beijing. The bacteria made up a significant fraction of the particulate matter in the smog. Now they have taken a closer look. They collected air samples during four haze episodes in 2017 and 2018 and examined the particles of bacteria present. They were far more numerous and larger when the haze was bad than at other times.

1-11-19 Medication and depression
Your medicine cabinet could be making you blue. More than one-third of Americans are now taking medications that can cause depression as a side effect, according to a new study. Researchers identified about 200 prescription drugs that can cause the mood disorder, including many common medications taken by older adults, such as proton-pump inhibitors (PPIs), used to treat acid reflux, and beta blockers for hypertension. The study found that the more of these drugs people take, the greater their risk of depression. About 7 percent of participants taking one such drug were depressed, compared with 15.3 percent of those taking three or more. Many doctors “may not be aware that several commonly prescribed medications are associated with an increased risk of this disorder,” study author Mark Olfson, a professor at Columbia University Irving Medical Center, tells Consumer Reports. But other experts note that many people taking these medications already suffer from conditions that put them at a raised risk of depression. Up to half of people with chronic pain, for example, also have depression or another mood disorder—because the parts of the brain that process pain also affect mood.

1-11-19 What are the risks of dying from having the yellow fever vaccine?
On 10 January, renowned cancer doctor Martin Gore of the Royal Marsden Hospital in London died of organ failure shortly after getting the yellow fever vaccine, according to the Times newspaper. This has led to concern about the vaccine’s safety, particularly for older people – Gore was 67. Here’s what we know: What is yellow fever? It’s a mosquito-borne virus found in Africa, South America and the Caribbean. People infected with the virus develop flu-like symptoms. About 85 per cent of people recover but in 15 per cent it damages the liver and kidneys, causing internal bleeding that is often fatal. In recent years there have been a series of outbreaks in Africa, leading to a vaccine shortage. There are also fears the virus could spread to Asia. Did the yellow fever vaccine cause Gore’s death? We don’t know, contrary to some reports. The case should now go to the agency responsible for vaccine safety in the UK, the Medicines and Healthcare products Regulatory Agency, which will determine if the vaccine was the cause of death. Could the vaccine have killed him? Yes, although it is exceedingly unlikely. The yellow vaccine is a live vaccine – a harmless variant of the wild virus. In around 1 in 250,000 people, according to the US Centers for Disease Control (CDC), it causes “yellow fever vaccine-associated viscerotropic disease” – serious damage to internal organs. How many people have died as a result of the vaccine? Of the hundreds of millions given the yellow fever vaccine since it was introduced in 1936, there have been just 62 confirmed cases and 35 deaths from vaccine-associated viscerotropic disease, according to a 2016 study. It’s likely that cases have been missed in poor countries, but because the condition is so serious it is unlikely to go unnoticed in rich countries. Are there other risks of having the About one person in 55,000 experiences a severe allergic reaction to a vaccine component and one person in 125,000 experiences severe nervous system reaction. So overall the risk of serious side effects is very low, but still higher than other vaccines, where the risk is typically one in several million, says Ron Behrens of the London School of Hygiene & Tropical Medicine.

1-11-19 Earth’s missing chapter
An international team of scientists thinks it has solved one of geology’s great mysteries: What happened to a massive, missing layer of Earth’s crust? The Great Unconformity—a gap in the geological record of anywhere from 250 million years to 1.2 billion years—can be observed at the Grand Canyon, where the rocky layers offer a window into Earth’s history. One strata is made up of sedimentary rocks from the Cambrian period, which started some 540 million years ago, and below is a layer of crystalline rock that formed about 1 billion years ago. The new study suggests the missing layer or layers vanished during a hypothesized period known as Snowball Earth, when most of the planet was covered in ice, reports NationalGeographic.com. Researchers believe that roaming glaciers ground up a 3-mile-deep layer of the crust. Using a chemical analysis of ancient zircons—hardy minerals that lock in the geochemical conditions of their environment during formation—the scientists concluded the resulting sediment was dumped into the oceans and then sucked into Earth’s mantle by moving tectonic plates. “Earth does a really good job at erasing the tracks of its past,” says study co-author Bill Bottke, of the Southwest Research Institute in Boulder.

1-11-19 Nerve cells from people with autism grow unusually big and fast
Abnormal growth patterns might set the brain on a course to develop the disorder. Young nerve cells derived from people with autism are precocious, growing bigger and developing sooner than cells taken from people without autism, a new study shows. The results, described January 7 in Nature Neuroscience, hint that in some cases nerve cells veer off course early in brain development to ultimately cause the disorder. As a proxy of brain growth, researchers led by Simon Schafer of the Salk Institute in La Jolla, Calif., transformed skin cells from people with and without autism into stem cells that then developed into nerve cells in the lab. Along the way, the scientists monitored the cells’ growth and the behavior of their genes. Compared with cells derived from five people without autism, cells from eight people with autism grew bigger, with longer and more elaborate branches, the researchers found. Three-dimensional balls called organoids made of the autism-derived cells were bulkier, too. In addition to this physical development, a group of genes important for brain development switched on sooner. Trouble in the autism-derived cells, however, actually began a bit earlier, just as the cells were on the cusp of becoming nerve cells. At the neural stem cell stage, certain spots of these cells’ chromatin — tightly packed genetic material — were more open and accessible than they should have been, an unfolding that can lead to abnormally active genes. The results show that open chromatin “can have major effects on neuronal development,” says neuroscientist David Amaral of the University of California, Davis.

1-10-19 Taking ginger pills can make disgusting ideas more palatable
We often say our sense of morality is guided by our gut feelings – and this may be truer than we realise. A set of experiments using the anti-nausea powers of ginger have provided the strongest evidence yet that bodily sensations play a key role in some of our moral judgements. Previous studies have reported that the more disgusted people feel, the more wrong they judge moral infractions to be. However, it’s not clear whether feelings of disgust guide moral judgements, or if it is the other way around. To find out, Jessica Tracy and her colleagues at the University of British Columbia, Canada, carried out a series of experiments using ginger, which has anti-nausea effects. Half the volunteers were given ginger in capsules and half were given placebos, without knowing which. In the first test, 242 subjects were shown disgusting photos and then asked to rate how disgusted they felt. Ginger reduced feelings of disgust towards moderately disgusting photos, such as snot in a napkin, but not highly disgusting photos, such as vomit in a toilet. This is the first evidence that treatments that target physical feelings of nausea also help alleviate psychological feelings of disgust, suggesting that physical queasiness contributes to how we feel about a picture. Next, the researchers asked subjects how wrong they considered certain acts. Initially, they focused on so-called “purity violations” – situations that include touching dead bodies or faecal matter. “In human cultures throughout history, moralising about these things was an effective way to prevent people from engaging in behaviours that would transmit germs,” says Tracy. They found that, when people were given ginger, they made less harsh judgements about moderate purity violations, such as drinking from a never-used toilet bowl. But like in the first experiment, the ginger wasn’t enough to curb reactions to more extreme scenarios, such as sex between cousins.

1-10-19 ‘Little Foot’ skeleton reveals a brain much like a chimp’s
But the ancient hominid’s inner ear shows a mix of humanlike and apelike features. An ancient hominid skeleton dubbed Little Foot possessed a brain largely similar to that of modern chimpanzees and an inner ear with a mix of apelike and humanlike features, two studies suggest. These findings, along with other analyses of the adult female’s 3.67-million-year-old skeleton, point to the piecemeal evolution of humanlike traits in close relatives of our species, scientists say. The research is part of the first formal analyses of Little Foot’s skeleton, which was discovered more than 20 years ago in a South African cave but was recently removed from its rocky encasing. Other analyses of trunk and limb bones indicate that Little Foot, who lived perhaps a million years before the emergence of the human genus, Homo, already walked upright about as well as people today do (SN: 1/19/19, p.13). Although Little Foot consists of a nearly complete skeleton, her evolutionary identity is controversial. Paleoanthropologist Ronald Clarke of the University of the Witwatersrand in Johannesburg — Little Foot’s discoverer and a coauthor of the two new studies — assigns the find to Australopithecus prometheus, an early extinct hominid species that many scientists don’t regard as valid. Other researchers regard Little Foot as an early member of Australopithecus africanus, a species previously known from fossils discovered at several South African sites (SN: 1/19/19, p. 13). In one of the new studies, Witwatersrand paleoanthropologist Amélie Beaudet and her colleagues compared a 3-D digital reconstruction, or endocast, of Little Foot’s brain surface with digital endocasts of 10 other South African hominid specimens dating to between roughly 1.5 million and 3 million years ago.

1-9-19 Millions of years ago a massive whale-eating whale roamed the seas
Millions of years ago a mega whale species roamed the oceans. Now an analysis of their stomach contents reveals they may have been top of the food chain, and even eaten other whales. Basilosaurus isis could grow to 18-metres in length, three times that of orcas. They lived 38 to 34 million years ago in the Atlantic Ocean near modern North Africa. Nine years ago, a skeleton of a B. isis was found in northern Egypt, and it wasn’t alone. Fragmented bones from several fish were also unearthed from the same site. Scientists identified at least two smaller ancient whales, a bony fish and a shark. Manja Voss at the Museum of Natural History in Berlin and her colleagues analysed the location of the other bones relative to B. isis. They found all of them were clustered in or near the B. isis’ rib cage, where the its stomach would have been. Additionally, deep bite marks were found on the skulls of the smaller whales that match the shape of B. isis’ teeth. These suggests that B. isis had the ability to actively attack and prey on smaller whales and sharks that were also teethed predators that consume other animals. B. isis was at the top of the food web, making it the apex predator in its ecosystem, says Voss. “This is the first stomach content found in B. isis, and also first direct evidence for diet in that species,” she says. “The study extends our knowledge of ancient whales and completes the bigger paleo-ecological picture.”

1-9-19 In the beginning: The full story of life on Earth can finally be told
The events of the first 3.5 billion years of evolution are coming to light at last and they include far more drama and intrigue than we ever imagined. MOST accounts of life on Earth begin little more than half a billion years ago. That is when an evolutionary burst of creativity produced the ancestors of almost all animals and plants alive today. Following this “Cambrian explosion”, life’s story is one of fish, amphibians, insects, land plants, the rise and fall of the dinosaurs, and ultimately the emergence of humans. It is an epic tale – but it spans just one-eighth of life’s history. The problem is that although animals and plants have left abundant fossils, Precambrian rocks contain almost no traces of earlier life. This vexed Charles Darwin, who wrote in On the Origin of Species: “To the question why we do not find records of these vast primordial periods, I can give no satisfactory answer.” Since then, a few fossilised remains have been found, but these are mostly microscopic blobs, reluctant to give up their secrets. Yet, in recent years, ingenious researchers have found new ways to lift the lid on life’s black box. This is the story of the first 3.5 billion years. It is a tale dominated by single-celled organisms, but it is also one of cataclysmic change. It encompasses the birth of the continents, the greatest act of chemical pollution ever committed, and a freak evolutionary event that may never have happened anywhere else in the universe. It is an epic journey, so buckle up. In the beginning was Earth. It formed some 4.54 billion years ago from rocks and dust and, soon afterwards, was smacked in the face by another baby planet (or possibly several small ones). The impact melted Earth’s surface and threw chunks of matter into orbit, forming the moon. Where one vital ingredient for life, Earth’s water, came from is a long-running debate. It may have been locked up in the rocks that formed the planet, been brought in later by comet, or perhaps it came from interstellar space and is older than the sun itself.

1-9-19 Don’t panic about children’s screen time, try these tips instead
Alleged dangers of screen time have been exaggerated, worrying parents. Here are some guidelines to ensure screens are used positively, says paediatrician Max Davie TODAY’S children are growing up in an environment dominated by screens. Whether it is learning in school through computer or tablet use, relaxing at home with video games and TV or communicating with friends on phones and social media, time spent on screens has become an essential part of modern life. Amid this, much has been made in the media about the alleged dangers of screen time and the risks that it poses to young people’s health. As a paediatrician, I regularly speak to parents who are concerned about the amount of time their children spend glued to gadgets, but this panic isn’t new. People have been voicing concerns about the harms of spending too much time on screens since the invention of television. The truth is, the evidence for direct harm by screen time has always been contested. Although existing research demonstrates negative associations between screen time and mental health, sleep and fitness, we cannot be confident that these links are causal, or whether other factors are behind both negative health outcomes and higher screen time. In fact, a few more recent high-quality studies show that some screen time is better for mental health than none at all. To help clear things up, we at the UK’s Royal College of Paediatrics and Child Health have put together some guidelines to help families better manage their use of screens. We recommend that parents approach screen time in a way that works with the child’s developmental age, the individual needs and the value the family places on positive activities such as socialising, exercise and sleep.

1-9-19 Medieval dental plaque suggests women played important role as scribes
Tiny particles of the precious pigment lapis lazuli found in the teeth of a medieval woman suggest she was a scribe producing high-quality illustrated manuscripts. The discovery adds to evidence that female scribes copied far more books during the Middle Ages than thought. “For reasons of humility women tended not to sign their works,” says archaeologist Christina Warinner at the University of Zürich in Switzerland. “There is this widespread bias shared by a lot of historians that book production was done by men only.” The finding came about by accident when Warinner’s team set out to study oral microbiomes by looking at mineralised plaque on the teeth of ancient skeletons. One of the skeletons came from a medieval cemetery near Dalheim in Germany associated with a religious community. It was excavated decades ago during building work. This skeleton had blue plaque, but finding out why required a long investigation by physicists and historians as well as archaeologists. Eventually an analytical technique called micro-Raman spectroscopy revealed that the vivid blue particles in the plaque were lapis lazuli. “It was a very big surprise to us, because lapis lazuli was so rare and expensive,” says Warinner. “And genetic tests determined that it was a woman, which was not what we expected.” There are four possible explanations. There’s “devotional osculation” – the practice of kissing figures in illuminated prayer books. But devotional osculation didn’t become popular until after 1300 AD, and the skeleton dates to between 1000 and 1160.

1-9-19 Paint specks in tooth tartar illuminate a medieval woman’s artistry
It wasn’t just monks who scribed and illustrated elaborate religious texts. Remnants of a rare pigment found in dental tartar of a woman buried around 1,000 years ago at a medieval monastery indicate that she may have been an elite scribe or book painter. These pigment flecks come from ultramarine, a rare blue pigment made by grinding lapis lazuli stone imported from Afghanistan into powder, say archaeologist Anita Radini of the University of York in England and her colleagues. Elaborately illustrated religious manuscripts produced during Europe’s Middle Ages, from around 1,600 to 500 years ago, were sometimes decorated with rare and expensive materials, including ultramarine and gold leaf. The new discovery, reported January 9 in Science Advances, supports recent historical research suggesting that it wasn’t just monks who prepared these richly decorated books. Nuns did, too. The presumed female book painter was identified as part of a study examining the chemical makeup of or dental plaque from individuals buried next to a women’s monastery at Germany’s Dalheim site. Radiocarbon dating places the woman’s death at between roughly 1,000 and 800 years ago. Based on the distribution of pigment in her mouth, the woman was probably licking the end of a brush in order to create a fine point while painting, the researchers say.

1-9-19 Blue tooth reveals unknown female artist from medieval times
The weird habit of licking the end of a paintbrush has revealed new evidence about the life of an artist more than 900 years after her death. Scientists found tiny blue paint flecks had accumulated on the teeth of a medieval German nun. The particles of the rare lapis lazuli pigment likely collected as she touched the end of her brush with her tongue. The researchers say it shows women were more involved in the illumination of sacred texts than previously thought. When they examined the teeth of one subject, called B78, it ultimately revealed far more than what she had eaten. According to radiocarbon dating, the woman had lived between 997 and 1162AD and was between 45-60 years old when she died. According to the authors, the woman was average in almost every aspect - except for what was stuck to her teeth. When the researchers dissolved samples of her dental calculus, they couldn't believe their eyes. Hundreds of tiny blue particles became visible. "Dental calculus is really cool, it is the only part of your body that fossilises while you are still alive," senior author Dr Christina Warriner, from the Max Planck Institute for the Science of Human History in Jena, Germany, told BBC News. "During this process it incorporates all sorts of debris from your life, so bits of food become trapped, it ends up being a bit of a time capsule of your life." "We found starch granules and pollen but what we also saw was this bright, bright blue - and not just one or two little flecks of mineral, but hundreds of them. We had never seen that before." It took some major scientific sleuthing to work out what the particles were made of. Eventually, the scientists realised they were dealing with lapis lazuli, a rare and valuable pigment, that originated from a mountain in Afghanistan. The lapis would be ground into a powder and mixed to make ultramarine - a vivid blue, so expensive that artists like Michelangelo weren't able to afford it. It was used in Medieval Europe to decorate only the most valuable religious manuscripts.

1-9-19 Studies can be in vitro, in vivo and now ‘in fimo’ — in poop
Feces contain valuable scientific information that gives clues about overall health. Poop contains a lot of valuable scientific information. Researchers can monitor microbes, track enzyme activity or hunt for DNA to gather clues about overall health. There’s so much one can learn from the waste product that microbiologist Aadra Bhatt at the University of North Carolina at Chapel Hill decided there should be a word for that research — something in the same vein as “in vivo” (research done in living animals) and “in vitro” (research done in a petri dish). After some linguistic digging, she and two colleagues settled on “in fimo.” The term comes from fimus, one of several Latin words for manure or excrement. Their choice won out over the more obvious option of “in feces” because the word feces doesn’t have the same rich scatological legacy — originally it referred to the dregs in a wine cask, Bhatt says. She and her colleagues, while already using in fimo at meetings and seminars, published their argument online December 13 in Gastroenterology. Compared with the laborious process of pulling together a scientific paper, coming up with this term was “delightful — and it wasn’t particularly drawn out,” Bhatt says. She hopes the word catches on and gains a place in the lexicon for poopetuity.

1-9-19 'New' apple and pear varieties found in Wales
A total of 73 previously unrecorded varieties of apples and pears believed to be unique to Wales have been discovered by researchers. About 200 trees were DNA-tested in the two-year project to find, catalogue and preserve new varieties. Some have been propagated and are now being grown in 13 community orchards around Wales. The lottery funded project was run by the University of South Wales and the Welsh Perry & Cider Society. One variety, called Anglesey Sweet Jane (A1789), was found growing on land on Anglesey. The owner's mother, aged in her 80s, told researchers she remembered the tree, thought to be more than 100 years old, from her childhood. The variety takes its name from the owner's sister, and the "fruit is quite sweet" making it most likely an eater, said researchers. Another apple, known as Afal Tudwal (A1797), was found growing in an old orchard attached to a vicarage in Llanstadwell, Pembrokeshire. Researchers said its taste was "sharp but not unpleasant" and it had been used as a "cooker" and for cider. "When we launched this project none of us could have foreseen the huge success of the DNA testing results that would come from it," said society chairwoman Sally Perks. "We hoped to find some unique varieties, but we didn't envisage that there would be so many varieties of cider apple and perry pear that have only been found in Wales." Their project was set up in 2016 to look at the heritage of orchards and cider-making in Wales and it has boosted known varieties from about 30 to more than 100.

1-8-19 Winning at work: Is flexible working actually a good idea?
Experiments show shorter weeks and remote working can boost productivity – as long as you can avoid the three enemies of fridge, bed and tv if working from home. Working from home. Unlimited holiday allowance. A four-day working week. Employers are increasingly offering flexibility in how we work. In the US in 2016, 43 per cent of employees said they had spent at least some time working remotely. We like these freedoms – but are they good for business? Andrew Barnes thinks so. In late 2017, he read that workers were properly productive for only a few hours a day (see “Winning at work: how to plan your day (and avoid the afternoon slump)”), so he decided to experiment with a four-day working week at the trust management company he founded in New Zealand. The idea was that employees would focus more to get their work done quicker, and get a paid day off in return. And they did indeed get the same amount of work done. Economist Helen Delaney at the University of Auckland, who surveyed the staff, says they felt “rested and rejuvenated upon returning to work, which enabled them to sustain the higher performance during the trial period”. She says the exercise has generated significant interest from trade unions and government. “There is curiosity, intrigue and a desire to learn,” she says. Working remotely seems to bring similar benefits. In 2013, economist Nicholas Bloom at Stanford University in California carried out a randomised trial at Ctrip, a Chinese travel agency employing 16,000 people. He and his team split 250 call centre workers into a group that remained in the office, and a group that worked full-time from home for nine months. Productivity, measured in terms of orders booked and calls answered, went up 13 per cent in the home working group. It rose a further 9 per cent when the employees chose where they worked: it became clear that working remotely was not for everyone. “There were some people who realised they did not get on with the three enemies of working from home: the fridge, the bed and the TV,” says Bloom.

1-8-19 Winning at work: Why hot-desking and open-plan offices are bad for you
Flexible workspaces that encourage collaboration and creativity are all the rage. But they ignore basic human psychology – and they could be counterproductive. I have serious office envy. Perhaps I shouldn’t ever google “world’s coolest workspace” or look at the glossies. All I see are interiors with vast walls covered in plants, flooded with natural light; huge rooms full of sleek, wooden furniture, and not a dangling cable in sight; swing chairs, beanbags, even giant slides instead of staircases. Instead, here I am in New Scientist‘s US office, where three of us inhabit a smaller room in a larger co-working space. There is a flimsy wall separating us from the office next door, where the noise level is often beyond the pale (see “Winning at work: How to stay focused and avoid distractions”). Outside our door, a larger open-plan space is packed with dozens of people with little room to spread out. Workers of the world, unite? Many of us spend more of our waking hours at work than we do at home, so it is reasonable to want a comfortable, functional and fun place to work in. Trouble is, there are no universal definitions of comfortable, functional and fun. What is clear, though, is that most of the received wisdom about how to design an office is questionable at best. Two trends have dominated workplace design in the past few decades: open-plan offices, where everyone sits in the same space, and “non-territorial” or hot-desking offices, where no one has their own place. The stated aim of both is to foster creativity and collaboration – by having everyone within sight in an open-plan office for example. But while there is some evidence that workers do move around more in open-plan settings, and so benefit from increased physical activity (see “Winning at work: how to create the perfect desk space”), it seems it’s not to talk to each other. The lack of privacy in an open-plan setting makes us retreat into our shells, putting on headphones to block background noise and emailing and instant messaging people just a few desks away, according to a 2018 study.

1-8-19 A protein in mosquito eggshells could be the insects’ Achilles’ heel
New research on the bloodsuckers may one day help control their number. Mosquito researchers may have hatched a new plan to control the bloodsuckers: Break their eggshells. A protein called eggshell organizing factor 1, or EOF1, is necessary for some mosquito species’ eggs and embryos to develop properly, a new study finds. Genetically disrupting production of that protein in Aedes aegypti mosquitoes caused about 60 percent of their normally dark eggshells to be pale. And shells lacking EOF1 often collapsed and were more porous than normal. In experiments, almost no mosquito embryos in the EOF1-disrupted eggs hatched into larvae, researchers report January 8 in PLOS Biology. EOF1 is produced only by Aedes, Anopheles and Culex mosquito species, biochemist Jun Isoe of the University of Arizona in Tucson and colleagues discovered. Those varieties of mosquitoes can transmit life-threatening diseases such as malaria, Zika, dengue and West Nile virus (SN: 11/10/18, p. 22). The protein could be a good target for genetic engineering techniques or insecticides, which may help control populations of disease-carrying mosquitoes without killing harmless insects, the researchers speculate. “This is truly outside-the-box thinking, and I like that,” says entomologist Joe Conlon, a technical adviser for the American Mosquito Control Association, an organization based in Mount Laurel, N.J., that helps individuals, companies and public health agencies control mosquitoes and other disease-spreading insects.

1-8-19 Exclusive: Cuba failed to report thousands of Zika virus cases in 2017
THOUSANDS of Zika virus cases went unreported in Cuba in 2017, according to an analysis of data on travellers to the Caribbean island. Veiling them may have led to many other cases that year. The analysis suggests that Zika infections peaked in Cuba in the second half of 2017, at a time when the virus was waning in mainland North and South America. Cuban authorities didn’t follow the agreed practice of notifying the Pan American Health Organization (PAHO) of the outbreak. Cuba’s first case of Zika occurred in March 2016. A PAHO report says the country stopped providing updates on Zika in January 2017. In press reports in May 2017, Cuba said that nearly 1900 infections had been detected up to that point. But Nathan Grubaugh at the Yale School of Public Health and his colleagues estimate that the total cases in 2017 alone would have been more than double that at 5700. “Our results therefore suggest that the 2017 Zika outbreak in Cuba was similar in size to the known 2016 outbreaks in countries with similar population sizes,” the authors write. They declined to comment on the work because it is under review for publication in a journal. The team looked at the travel logs of 184 people who had contracted Zika while abroad and found that 95 per cent had been to Cuba. Such “hidden” outbreaks can spread epidemics to other countries because travellers and health authorities are unaware of the heightened risk of infection, the authors write (bioRxiv, doi.org/czdk).

1-7-19 Core set of genes explain why some animals stick to one mate at a time
A common set of genes may determine whether all sorts of animals – from mice to fish – mate with one partner or many. Rebecca Young and Hans Hofmann of the University of Texas at Austin and colleagues looked at which genes are turned on in the brains of males in five pairs of closely related species: two mice, two voles, two songbirds, two frogs and two cichlid fish. Each pair included one monogamous species and one non-monogamous species. They analysed the patterns of gene expression to look for genes that were consistently more active or less active in monogamous species than their non-monogamous relatives. Although the 10 species in the study last shared a common ancestor 450 million years ago, the results show that the five species that have evolved monogamy have a similar pattern of gene expression in the brain. This isn’t too surprising from the point of view of an evolutionary biologist, says Hofmann. “All the things that happen in our bodies have an evolutionary history that leads back to a common ancestor, and there are only so many different ways to solve a problem,” he says. For most animals, mating with multiple partners is advantageous, so monogamy is the exception rather than the rule. But for some species, it pays to remain faithful – particularly those that rarely encounter any prospective partners. One of the species in the study is the mimic poison frog, the first known monogamous amphibian. It raises its offspring in small pools where there is little to eat, so the tadpoles need help from both parents to get enough food to reach adulthood. Monogamy typically entails a set of related behaviours, including forming pair bonds, sharing some parental duties and defending territory.

1-7-19 A hormone released during exercise might protect against Alzheimer’s
A hormone released during exercise may protect the brain against Alzheimer’s disease. It may also explain the known positive effects of exercise on mental performance. Irisin is a hormone generated by muscle tissue that is carried around the body in the bloodstream. Fernana de Felice at the Federal University of Rio de Janerio and colleagues found that people with Alzheimer’s had lower levels of the hormone compared with healthy individuals. In tests with mice, the team could induce learning and memory deficits by cutting out irisin and could reverse the effects by restoring the hormone. When irisin signalling was blocked in mice with a rodent version of Alzheimer’s, the brain benefits of physical exercise were lost. “We know that physical activity is linked to better brain health as we age, and this research highlights a biological mechanism that may contribute to this beneficial effect,” says Rosa Sancho at the charity Alzheimer’s Research UK. Some people who are unable to regularly exercise but have dementia or are at high risk of dementia could one day be given drugs to to target irisin. “Drugs designed to target the hormone identified in this research could potentially bring some of the benefits of physical activity to people who may be less able to exercise.” “Although this study was only in mice, it adds to mounting evidence of the relationship between lifestyle factors, like physical fitness, and dementia,” says James Pickett at the Alzheimer’s Society charity.

1-7-19 Ditching Facebook could reduce stress but also make you less happy
Hoping to start a relaxing year? Try quitting social media. People who gave up Facebook for five days experienced a decrease in stress, but they also reported a lower life satisfaction. Thanks to social media, we can check in with our friends and family like never before. But previous studies have found that this can lead to a fear of missing out, resulting in increased anxiety levels and decreased sleep quality. Wondering what a break from Facebook would do to a person’s well-being, Eric Vanman at University of Queensland in Australia and his colleagues recruited 138 active Facebook users and asked 60 of them to drop Facebook for five days. The other half of the participants were told to use Facebook normally. The team found that people who gave up Facebook had a significant decrease in their cortisol levels after five days, suggesting they were less stressed. But they also reported that they were less satisfied with their lives than before the experiment started. There was no change in the control group. Vanman says that one explanation could be that these participants were not prepared to disconnect from their friends – a main reason they joined Facebook in the first place. So, even though quitting the platform could reduce some of their stress levels, it wasn’t what they actually wanted to do. Cortisol levels are not just linked to stress, they are also affected sleep quality and quantity, says Melissa Hunt at the University of Pennsylvania in Philadelphia. “Lots of young people stay up late or even wake up in the middle of the night to check social media,” she says. “So [the decline in cortisol] could have been the result of improved sleep.”

1-7-19 Top geneticist calls for global rules for ethical human genome editing
A leading geneticist has said that scientists should draw up a clear set of dos and don’ts for those who want to perform human gene editing. “What we need is a detailed protocol of how you would go about this,” says Robin Lovell-Badge of the Francis Crick Institute in London, who thinks some could benefit from genome editing if it was done right. “We think this is the best way forward.” In November, the world was shocked when Chinese scientist Jiankui He announced he had created the world’s first genome-edited babies. He was trying to make individuals immune to HIV but the two girls born already may not be immune to HIV and could be far more vulnerable to flu. He’s actions have been widely condemned as unethical for this and many other reasons. “It’s clear he had not done enough homework,” says Lovell-Badge, who helped persuade He to reveal the details of his work in a talk at a genome-editing summit in Hong Kong. In private, He apparently compared himself to the IVF pioneer Bob Edwards, whose work has led to the birth of millions of babies around the world. But Edwards did not work in secret, says Lovell-Badge. Edwards was open about his team’s work long before the implantation of Louis Brown, the first person born after IVF. Yet He was convinced what he did was right and he appears to have convinced others too, including the ethics committee of the local hospital – though the hospital has since denied giving its approval. Drawing up a clear set of rules would help those tasked with assessing the ethics of proposals, Lovell-Badge told journalists at a briefing in London on 7 January. “This has not been done. It’s something that should be done.” If this set of rules was widely accepted around the world, it could help prevent further unethical attempts, he said. (Webmaster's comment: Progress will continue to be made by courageous scientists in spite of the rules that are made up by those that wish to control science.)

1-7-19 Incredible 'sea monster' skull revealed in 3D
Some 200 million years ago in what is now Warwickshire, a dolphin-like reptile died and sank to the bottom of the sea. The creature's burial preserved its skull in stunning detail - enabling scientists to digitally reconstruct it. The fossil, unveiled in the journal PeerJ, gives a unique insight into the life of an ichthyosaur. The ferocious creature would have fed upon fish, squid and likely others of its kind. Its bones were found in a farmer's field more than 60 years ago, but their significance has only just come to light. Remarkably, the skull is three-dimensionally preserved and contains bones that are rarely exposed. "It's taken more than half a century for this ichthyosaur to be studied and described, but it has been worth the wait," said palaeontologist Dean Lomax of the University of Manchester. Thanks to data collected from CT scans, researchers Nigel Larkin and Laura Porro were able to digitally reconstruct the entire skull in 3D. "CT scanning allows us to look inside fossils - in this case, we could see long canals within the skull bones that originally contained blood vessels and nerves," said Dr Porro.

1-6-19 An epidemic of loneliness
Nearly half of all Americans today say they are lonely. Why is that so, and what are the consequences. Nearly half of all Americans today say they are lonely. Why is that so, and what are the consequences? Here's everything you need to know:

  1. How is loneliness defined? Loneliness isn't determined by the actual number of friends or social contacts a person has. Social science researchers define loneliness as the emotional state created when people have fewer social contacts and meaningful relationships than they would like — relationships that make them feel known and understood.
  2. What impact does loneliness have? It makes people sick. A 2010 study by Brigham Young University found that loneliness shortens a person's life by 15 years, about the same impact as being obese or smoking 15 cigarettes a day.
  3. Why is physical health affected? Stress. The feeling of loneliness, scientists say, is an evolutionary phenomenon. Just as hunger encourages animals to find food, loneliness forces humans to seek out the protection of the group, increasing the chances of survival.
  4. Is isolation more common? It appears to be. Between 1985 and 2009, the average American's social network shrank by more than one-third, defined by the number of close confidants.
  5. Why are so many young people lonely? Americans are getting married and having children later in life; there are now more single people in the U.S. than at any time in the past 140 years. Not being part of a regular workplace also plays a role, with freelancers and "gig economy" workers reporting higher levels of loneliness.
  6. Alone, angry — and intensely partisan: Some researchers believe that America's increasingly polarized politics — and the partisan viciousness on social media — may be at least partly the product of increasing loneliness.

1-5-19 The health benefits of being in nature
A little bit of greenery can go a long way. Here's a novel way to keep health-care costs down: Plant more trees. That might seem like a non sequitur, but considerable research has linked green space with better human health. A recent study provides new evidence for this beneficial connection, along with at least a partial explanation for its power. The study finds that people who live in leafier areas have lower levels of several stress-related biomarkers, including adrenaline. In addition, they have an enhanced ability to grow and repair blood vessels. "Increasing the amount of vegetation in a neighborhood may be an unrecognized environmental influence on cardiovascular health," said lead author Aruni Bhatnagar, professor of medicine at the University of Louisville. He called such an effort "a potentially significant public-health intervention." The study, in the Journal of the American Heart Association, featured 408 people recruited at a preventive cardiology clinic in Louisville, Kentucky. All were either diagnosed with, or considered at high risk of, cardiovascular disease. The researchers measured the impact of stress on their bodies using a variety of measures, including the level of the hormone epinephrine (a.k.a. adrenaline), which is released as part of the well-known fight-or-flight response. Additionally, in a subgroup of 255 participants, they measured the level of specific blood cells that are key to building and repairing vessels. Using satellite imagery, they recorded the amount of green space in the immediate vicinity of their homes (up to 0.6 miles from their door). "Residential proximity to vegetation was associated with cardiovascular health, as reflected by a range of biomarkers of cardiovascular injury and disease risk," the researchers report. Specifically, people living near green spaces had lower levels of stress-activated hormones including adrenaline, and higher levels of those specialized blood cells that help keep the vascular system healthy.

1-5-19 In search of an inner Neanderthal
A couple of years ago I purchased a pair of 23andMe kits for myself and my husband, Tomer. I intended to scientifically prove that Tomer's most irritating behaviors were genetic destiny and therefore unchangeable. I'd grown tired of nagging him — oftentimes, I'd hear my own voice rattling inside my brain in the same way a popular song might get stuck in my head. I needed an out, something to push me toward unconditional acceptance of my husband. My constant complaining yielded zero behavior modification on his part; on the other hand, it was changing me into a nasty micromanager. I briefly considered marital therapy, but that's an expensive undertaking, costing much more than the $398 one-time fee for both DNA kits. Plus, couples' therapy could take a long time, requiring detours through our shared history. In much appealing contrast, 23andMe promised to launch us straight back to our prehistoric roots, and might provide Tomer with something akin to a formal pardon note, thereby permitting me to stop fighting against him, once and for all. I imagined we could help others by way of example too, for what long-married woman has not suffered her husband's most banal tendencies — the socks and underwear on the floor, the snoring? Not me, because my husband puts his used clothes in the hamper and I'm the snorer. Really, I'm probably blessed as far as masculine disgustingness goes. But my husband is flawed in one repulsive way: his barbaric table manners. I have no doubt this is a genetic situation, for even back when we were first dating I'd shuddered upon seeing my future father-in-law poke through the serving bowls of a family-style meal with his bare hairy hands. My husband's father has also been caught eating ice cream directly from the carton (the thought of which I now appreciate for its built-in binge deterrent). Moreover, my father-in-law eats like a caveman-conqueror, reaching across dinner plates to pluck a taste of this or that from his mortified tablemates. (Webmaster's comment: We are all barbarians in our unconscious minds and the only way to override what it tells us to do is to use the conscious part of our brains.)

1-5-19 The physics of panic
When people come together in a crowd, physical and emotional connections define their movement, state of mind, and will to act. Understanding crowds can help us manage the panic caused by a terrorist attack; a science of crowds is vital to managing many emergencies, especially when density becomes dangerously high. Panic or chaos in a crowd can kill or injure hundreds, as happened at the Love Parade in Germany in 2010, when thousands of attendees to an electronic dance music festival piled up as they tried to enter a narrow tunnel; 21 people died of suffocation. Fundamental science and public safety demand that we develop a complete science of crowds using a range of disciplines. Today, work by social psychologists shows that crowds are influenced by the personalities of individual members; thus, crowds can embody altruistic and helpful behavior as well as the opposite. And now we can extend crowd science further by incorporating quantitative analysis using classical and statistical physics, computational science and the theory of complex systems — the study of groups of interacting entities. One relevant concept from complexity theory is "emergence," which occurs when the interactions among the entities produce group behavior that could not have been predicted from the properties of any individual element. For instance, randomly moving H2O molecules in liquid water suddenly link up at zero degrees Celsius to make solid ice; starlings in flight quickly form themselves into an ordered flock. Emergent behavior can be predicted if the interaction among the entities is known, as shown in 2014 by researchers at the University of Minnesota who determined how two people in motion interact and, from that, how a crowd moves. The researchers first considered an idea from physics, theorizing that, like electrons, pedestrians avoid collision by repelling each other as they get closer. But video databases showed instead that when people see that they are about to collide, they change their paths. From this, the researchers derived an equation for what amounts to a universal force of repulsion between two people, based on time until collision, not distance.

1-4-19 Edinburgh scientists discover mammoth secret in ivory DNA
Scientists based at Edinburgh Zoo are cooperating to create a genetics laboratory in Cambodia to fight the illegal ivory trade. While trying to save elephants, they have found ivory from another animal that is now extinct. In the WildGenes laboratory of the Royal Zoological Society of Scotland, Dr Alex Ball is drilling what sounds like a giant tooth. Which is in effect what it is: an ornately carved elephant tusk. Dr Ball's team has helped establish the first conservation genetics laboratory in Cambodia. The country lies on an important route for smuggling ivory from Africa and Asia. Which continent the tusks have been stolen from can have legal implications. "Elephants are being decimated in their thousands across Africa," Dr Ball says. "One of the key things about Cambodia is that we have hardly any information about the ivory trade. DNA from tusks is unlocking those secrets. "We can basically break down that dentine and calcium and get those cells out the ivory - and then identify the individual that grew that tusk," he added. The WildGenes laboratory is the only zoo-based animal genetics lab in the UK and one of only a handful in Europe. The head of conservation and science at the Royal Zoological Society of Scotland, Dr Helen Senn, says it plays an important role. She continued: "Often endangered species are quite genetically unusual and unique and they haven't been worked on before. "They're not interesting to medicine or agricultural science. "So we have to develop novel methods to - for example - study pygmy hippos or scimitar-horned oryx." But in the work on Cambodian ivory samples the researchers have uncovered something even more exotic: DNA from woolly mammoths.

1-4-19 Body fat and breast cancer
Older women with excess body fat have a heightened risk of developing breast cancer, reports CNN.com—even if they have a normal body-mass index. Researchers tracked the body composition of 3,460 American women ages 50 to 79, all of whom had gone through menopause and had a supposedly healthy BMI, for an average of 16 years. Of those women, 146 developed estrogen-dependent breast cancer. The researchers found that an 11-pound increase in whole-body fat mass was linked to a 35 percent increased risk of contracting the disease. A similar fat mass increase in the torso was linked to a 56 percent rise in risk. An 11-pound mass increase was also connected to a higher risk of invasive breast cancer: 28 percent for whole-body weight gain, and 46 percent for an increase in torso fat. BMI is calculated through a formula involving height and weight, and doesn’t factor in fat. But “it makes sense that if you have excess fat, you will also have increased inflammation and elevated cancer risk, even if BMI is normal,” says lead author Andrew Dannenberg, a cancer specialist at Weill Cornell Medicine.

1-4-19 Aerobic exercise vs. aging
If you want to battle the negative biological effects of growing old, you might want to take up an aerobic exercise such as jogging or swimming. German scientists recruited 124 middle-aged men and women who were healthy but didn’t exercise and assigned them workout routines for the next six months. By the end of the study period, those who had been asked to jog or walk briskly for 45 minutes three times a week, or to do a high-intensity interval program, had developed longer telomeres in their white blood cells, reports The New York Times. Telomeres are tiny caps on the ends of chromosomes that protect DNA from damage. These caps shrink as humans get older, eventually resulting in cell death and disease. But aerobic exercise appeared to lengthen the participants’ telomeres, dialing back the aging process. Scientists found no lengthening in the telomeres of participants who took up weight training. The message of the study, says lead author Christian Werner, is that aerobic exercise is good for people of any age. “It is not too late,” he says, “to keep your cells young.”

1-4-19 Tools shake up humanity’s story
Archaeologists have discovered a hoard of 2.4 million–year-old stone tools in Algeria, a find that could upend the long-held theory that humanity first emerged in East Africa. The 250 sharp-edged implements were stashed some 200 miles east of Algiers, alongside an array of fossilized animal bones with cut marks—possible evidence of prehistoric butchery. The artifacts resemble tools previously unearthed only in East Africa and predate other tools found in North Africa by at least 600,000 years. Scientists had believed that early humans, our ancient ancestors, stayed in East Africa for millions of years before eventually spreading across the continent. The new discovery throws up two possibilities: that primitive tool-using hominins from East Africa spread across the continent much faster than previously thought, or that early hominins were developing tools in different parts of Africa at the same time. “The evidence from Algeria shows that the cradle of humankind was not restricted to only East Africa,” study leader Mohamed Sahnouni, from Spain’s National Research Centre on Human Evolution, tells NewScientist.com. “The entire African continent was the cradle of humankind.”

1-4-19 A subterranean ecosystem
The ground beneath our feet is teeming with a diverse ecosystem that is almost double the size of all the life found in the world’s oceans. That’s the conclusion of 1,200 scientists who are nearing the end of a decade-long international project to examine the mysterious microbes that inhabit Earth’s subsurface, reports ScienceDaily.com. Researchers with the Deep Carbon Observatory gathered samples from hundreds of underground sites around the world—including diamond mines, 3-mile-deep boreholes, and underwater mud volcanoes. They calculated that the subterranean ecosystem could contain up to 25 billion tons of carbon—hundreds of times more than is woven into all 7.5 billion humans. Some 70 percent of the microbes on Earth are thought to live in the subsurface, including many organisms that are unlike anything above ground. Some breathe uranium and expel the waste as crystals, while others live in deep-sea hydrothermal vents with temperatures of 250 degrees Fahrenheit. “It’s probably reasonable to assume that the subsurface of other planets and their moons is habitable,” says Rick Colwell, a professor from Oregon State University, “especially since we’ve seen here on Earth that organisms can function far away from sunlight.”

1-3-19 DNA tests of Lassa virus mid-outbreak helped Nigeria target its response
Analysis of genetic data in the field eased worries that a more transmissible strain had arisen. When an outbreak of a viral hemorrhagic fever hit Nigeria in 2018, scientists were ready: They were already in the country testing new disease-tracking technology, and within weeks managed to steer health workers toward the most appropriate response. Lassa fever, which is transmitted from rodents to humans, pops up every year in West Africa. But 2018 was the worst season on record for Nigeria. By mid-March, there were 376 confirmed cases — more than three times as many as by that point in 2017 — and another 1,495 suspected. Health officials weren’t sure if the bad year was being caused by the strains that usually circulate, or by a new strain that might be more transmissible between humans and warrant a stronger response. New technology for analyzing DNA in the field helped answer that question mid-outbreak, confirming the outbreak was being caused by pretty much the same strains transmitted from rodents to humans in past years. That rapid finding helped Nigeria shape its response, allowing health officials to focus efforts on rodent control and safe food storage, rather than sinking time and money into measures aimed at stopping unlikely human-to-human transmission, researchers report in the Jan. 4 Science. While the scientists were reporting their results to the Nigeria Centre for Disease Control, they were also discussing the data with other virologists and epidemiologists in online forums. This kind of real-time collaboration can help scientists and public health workers “see the bigger picture about pathogen spread,” says Nicholas Loman, a microbial genomicist at the University of Birmingham in England who was not involved in the research.

1-3-19 Probiotics don’t help puking kids, two large trials suggest
Probiotics didn’t shorten bouts of stomach flu in kids, two large studies found. There’s no sorrier sight than a puking preschooler. That’s the conclusion I recently reached around 2 a.m. as my poor 4-year-old heaved into the dim abyss. Luckily, her bout with the stomach flu was brief, and she was feeling better by the next day. Stomach flu, also known as gastroenteritis, is a common affliction caused by bacteria or viruses that inflame the gut. Though mercifully short, the misery this brings is complete, for both the sufferer and the person charged with scrubbing chunks out of sheets, carpet and a stuffed toy cupcake. So when presented with something that could potentially cut short the puking, any parent would jump at the chance. That’s the promise of probiotics, “good” bacteria (typically in pill form) that some people think might help restore the irritated gut and get kids feeling better faster. But according to two big studies (here and here) of puking kids and probiotics, parents should save their money for something else. For both studies, scientists studied kids ages 3 months to 4 years who came to an emergency department with acute gastroenteritis. In addition to receiving regular care, these kids took either a probiotic or placebo for five days. Then the researchers tallied up the kids’ symptoms to see if those who got the live bugs fared better than those who received a placebo. Long story short, the scientists found absolutely no differences.

1-3-19 Genome sequencing reveals disease risk in otherwise healthy babies
DNA sequencing is getting faster and cheaper, and it has been used to diagnose rare disorders in very sick children. But should it become a standard practice for healthy newborns? That’s the question asked by the BabySeq project, which has just released results from the first phase of its study. The sequencing trial included 32 sick infants in the intensive care units at three Boston-area hospitals, and 127 healthy children enrolled through the nursery at Brigham and Women’s Hospital in Boston. 140 of the 159 sequenced newborns were carriers of one or more genes associated with disease – they have the potential to pass these genes on to their children, but they are not at risk for the disease themselves. “Almost everybody is a carrier for recessive conditions. That’s what we would expect,” says Alan Beggs at Boston Children’s Hospital, who led the study. Of the sequenced group of babies, 9.4 per cent had genetic mutations that can result in childhood-onset diseases that can be treated with early intervention, such as heart disease or hearing loss. Eight babies had mutations that predict an adverse reaction to particular medications. One infant was found to have a deficiency in the enzyme biotinidase, which can lead to skin rash, hair loss and seizures. Their diet was supplemented with biotin to prevent such disease. Beggs says there are clear benefits to genomic sequencing, but there are also potential drawbacks. There is a concern over potential future discrimination by health or life insurers, or even future employers. A genetic test could also lead a patient to undergo more medical procedures, which can be costly and risky. There’s also the psychological burden on the parents of knowing something bad may happen, but not being able to do something about it.

1-3-19 Bereaved people unconsciously suppress thoughts of lost loved ones
After a bereavement, some people unconsciously suppress thoughts about their dead relative. Now for the process has been observed while someone lies in a brain scanner. The findings may shed light on people’s different coping styles after loss, says Noam Schneck of Columbia Engineering in New York. The brain scanner involved is known as an fMRI machine, which can reveal the activity of different parts of the brain, based on patterns of blood flow. This approach can enable a degree of mind-reading, and can be used to detect when a person is thinking of certain people or objects. Schneck’s team worked with 29 people who had recently lost a spouse or close relative. They were shown pictures of their loved one while in the scanner to determine the characteristic signature of brain activity linked with that person. The team also worked out the brain signature for trying to squash down unwanted thoughts, by getting them to do a tricky mental task requiring thought suppression. This involved having to name colours that words are written in, while ignoring the colour that the word spells out – for instance the word “green” in a blue font. Participants were next given an unrelated and boring task to do for twenty minutes to encourage mind-wandering. They were also asked throughout the task if they had thought of their dead relative in the past 30 seconds. In about a third of the answers, people said they had had such a thought – and their brain activity tallied with this. In the rest, they said they hadn’t; but sometimes during these periods, the team saw patterns of brain activity representing both the relative and the act of thought suppression, suggesting they were unconsciously repressing thoughts of the dead person.

1-3-19 Ice from the Alps reveals Europeans ditched gold for silver in AD 660
Ice in the Swiss Alps began to be contaminated with lead between AD 640 and 660. That suggests Europeans had begun producing large quantities of silver – releasing lead as a side-effect – 25 years earlier than we thought, which could help explain the rise of powerful towns like London. Historians have long known that north-west and central Europe largely abandoned gold coins for silver ones in the 600s, but exactly when and why has been unclear. “Numismatists had dated it on the basis of coinage,” says Christopher Loveluck of the University of Nottingham in the UK. They thought the switch happened around 675 or 680. Loveluck is part of a team that is analysing an ice core drilled from the Colle Gnifetti glacier in the Swiss Alps. New layers of ice were laid down each year, so the core provides a year-by-year record of environmental conditions. The team tracked when lead appeared in the record, because lead is a proxy for silver mining. “Silver in north-west Europe is found in galena, which is a lead-sulphide ore,” says Loveluck. “Silver is always the minor product.” The process of extracting the silver releases tiny particles of lead, which are carried away by the wind. Some ended up in the ice, revealing when the currency switch happened. “It actually occurred in two phases,” says Loveluck. “The first is in 640, when numismatists had already picked out that the gold coinage had been adulterated by a lot of silver.” But instead of the final switch occurring in 675 or 680, the team found a second big spike in lead levels in 660, suggesting it was in this year that there was a wholesale change to silver currency.

1-3-19 Pre-Aztec 'Flayed god' temple uncovered in Mexico
Archaeologists in Mexico say they have made an important discovery, uncovering a temple to Xipe Totec - the pre-Hispanic "Flayed lord". Historically, throughout the region, priests paid tribute to the deity by wearing the skin of human sacrifices. Items relating to the deity were discovered at a site in Puebla state, and believed to date from 900-1150 AD. Mexican archaeologists say the find may be the earliest dedication to Xipe Totec discovered in Mexico. Worship of the God, who represents fertility and regeneration, is known to have later spread throughout Mesoamerica during Aztec times. The INAH say the 85cm (33in) ceramic effigy of the god was found in relatively good condition, though some parts are unattached. They say a right hand was hanging by his left arm, symbolising the skin of a sacrificed person hanging over him. "Sculpturally it is a very beautiful piece," leading archaeologist Noemi Castillo said in a press release. "It measures approximately 80cm (31in) and has a hole in the belly that was used, according to the sources, to place a green stone and 'endow them with life' for the ceremonies." Two large skulls, believed to be carved from imported volcanic stone and weighing about 200kg (440lb) each were also discovered. Archaeologists from INAH believe the skulls were used as covers for holes placed in front of two sacrificial altars where they believe sacrifices to him were buried. All of the materials discovered have been sent to laboratories for official registering and further analysis. Xipe Totec is thought to have first appeared in the pre-Aztec era and is usually depicted in sandals, a loincloth and wearing the skin of human sacrifice. The festival of Tlacaxipehualiztli, which means to wear the skin of the skinning, was dedicated to him during spring during the Aztec period.

1-2-19 Poop provides a link in determining penguin diet from space
Poop can make things messy for Adélie penguins. But it can also provide information about the birds, including where they are and what they’re eating. The best way to find out what an Adélie penguin is eating is to catch it and make it regurgitate its meal. This is about as pleasant for bird and researcher as you might think. It’s also invasive, time-consuming and expensive to do on a large scale, so scientists need other ways to determine diet. Now they have one; it relies on images taken by Landsat satellites. The satellites don’t reveal individual penguins, let alone what they are consuming underwater. What those images do show, though, is poop. Lots of it. Because Adélie penguins cluster together at a predictable rate, researchers have figured out how to count penguin colonies just from their huge poop stains. Last year, for instance, a group led by Stony Brook University ecologist Heather Lynch reported finding a supercolony of 1.5 million Adélie penguins on the Danger Islands, off the coast of the Antarctic Peninsula, from their feces. Figuring out dietary preferences from those images is a bit more complicated — but it also starts with poop. Casey Youngflesh is a quantitative ecologist at the University of Connecticut in Storrs. Until a few months ago, he was a graduate student in Lynch’s lab. During that time, he made several trips to the Antarctic Peninsula, visiting Adélie penguin colonies by boat from either the tip of South America or the Falkland Islands. That required crossing some of the roughest waters on the high seas, and, he says, “it can get a little bit hairy sometimes, especially on the smaller vessels.”

1-2-19 This scientist watches meat rot to decipher the Neandertal diet
Nitrogen-15 levels in putrefying meat could explain high levels of the isotope in hominid fossils. Kimberly Foecke has a great relationship with her local butcher. Though she buys loads of meat, Foecke is not a chef or the owner of a small zoo. She’s a paleobiologist who studies what Neandertals ate. And that involves, in her words, “experimental putrefaction, which is a fancy way of saying, I rot meat, all day, every day.” Scientists know Neandertals ate a lot of meat. Fossilized bones from the hominids tend to have high levels of a heavier form of nitrogen, nitrogen-15, compared with the lighter form, nitrogen-14. Nitrogen-15 is least abundant in plants, and becomes more concentrated further up the food chain because it’s harder to break down than nitrogen-14. But exactly how much meat these hominids ate — and what else was in their diet — is somewhat controversial. Evidence such as tooth scrapings suggests that Neandertals also ate a variety of plants. But the nitrogen-15 measurements point to "an unreasonably huge amount of meat" in the diet, says Foecke, a researcher at George Washington University in Washington, D.C. Those levels tend to be even higher than what’s seen in top carnivores like hyenas, which nosh almost entirely on meat. Foecke thinks those high nitrogen-15 ratios may be explained not just by how much meat Neandertals ate, but also how they got it and prepared it. Perhaps whether meat was eaten fresh or rotten, raw or cooked, could influence the nitrogen-15 signal. That’s why she’s measuring nitrogen in cuts of beef, trying to pin down the biochemical changes that the meat undergoes as it rots.

1-1-19 How to make even your toughest new year’s resolutions stick
WE TRADITIONALLY greet the new year to the strains of Auld Lang Syne, and with rash promises of self-improvement, such as giving up alcohol for a month. I’m no different – over the last few years I’ve set myself new year’s resolutions with mixed results. Some, like my oath to visit the gym 100 times over the course of the year, were successful. Others, such as keeping on top of my taxes, were not. In fact, only 10 per cent of resolutions made in January will survive until December. Why do so many of us struggle to keep promises to ourselves? And can we do better? “As a species we tend to be biased to overconfidence and optimism,” says Keith O’ Brien at the Centre for Behaviour Change, University College London. “Come January, people tend to tick off all the things they want to do, and as a result try to do too much.” So what separates the successful from the rest of us? O’Brien says that setting goals without planning how you will achieve them is a recipe for failure. “If you have a goal for January 1st, you should prepare in advance with smaller changes,” he says, such as removing unhealthy snacks from the house if you want to give up eating junk food. That’s because willpower is like a muscle, and exercising it can give you a better chance of resisting the temptation to eat that second biscuit. Research also shows those who prepare for the worst are more successful in the long run. So always have a backup plan – if you know you can’t go to the gym in the morning, schedule an evening workout in advance.

1-1-19 Young people’s blood is being tested as a treatment for Parkinson’s
Blood from young adults is being trialled as a treatment for Parkinson’s disease by a firm that wants to use the therapy to target neurodegenerative conditions. Alkahest, a firm co-founded by Tony Wyss-Coray of Stanford University, California, has already tested blood-based treatments in people with Alzheimer’s disease. In the latest trial, 90 people with Parkinson’s – mostly in their 70s and 80s – will receive injections five days in a row, and then again three months later. Tests will determine whether the treatment improves their memory, attention, language skills or other cognitive abilities. The trial is inspired by research by Wyss-Coray and others at Stanford University showing that cognitive declines in old mice can be reversed by giving them injections of blood from young mice. Since this discovery, Wyss-Coray has been trying to work out precisely what it is in young blood that drives this anti-ageing effect. He and his team have spent the past few years injecting different extracts from young human blood into old mice to see which have the most restorative effects. They haven’t specifically sourced blood from young people, but are using blood from collection banks whose overall average donor age is 32. Although we don’t yet know why young blood may be rejuvenating, one idea is that younger bodies make restorative proteins that older bodies don’t. Wyss-Coray’s experiments have indicated that a certain “fraction” of young blood – a mixture of about 1000 different proteins – has particularly powerful effects. After old mice were injected with this fraction, they performed as well as young mice in cognitive tests, grew new brain cells and had less brain inflammation, says Alkahest CEO Karoly Nikolich. “We believe it contains the majority of beneficial proteins that are responsible for cognitive improvements,” he says.

1-1-19 Baby chicks could be given faecal transplants to ward off infections
Farmed chickens could receive faecal transplants to protect against the infections that cause food poisoning in humans. A pilot study suggests the transplants are remarkably effective, and the team behind it are now trying to make it work on an industrial scale. Paul Wigley at the University of Liverpool, UK struck upon the initial idea after hearing that babies born by Caesarean section may have an unusual mix of microorganisms in their guts, because they have not passed through their mother’s vaginas and picked up bacteria. “It hit me that every commercial chicken in the UK and other countries is the equivalent of a Caesarean section because there’s absolutely no contact between the chicken and the hen,” says Wigley. Wigley wondered whether he could give newly-hatched chicks a dose of the microorganisms they would otherwise miss out on by transferring them from adult chickens. His goal was to make the chicks less prone to Campylobacter infection – a bacterial infection and the biggest source of food poisoning from chicken. “They all thought I was absolutely bonkers,” he says. “We tried it and, much to our shock, it really did reduce the transmission of Campylobacter. The transplants appear to cause no ill effects. The chicks grow a little more slowly, so at 36 days they tend to be 1.9 kilograms rather than 2kg, but it’s not yet clear if this is a result of the faecal transplants. Wigley’s team are now figuring out how to do faecal transplants on a larger scale. To do this they need a less physically intensive process than performing the transplant by hand, as they did in the initial trial. Wigley thinks one option is to coat the microbes in a protected gel-coating that the chicks would then eat. A similar technique is used for vaccination.

1-1-19 Biggest archaeological dig in Europe will uncover UK’s buried history
THE most extensive archaeological dig in Europe is under way in the UK, thanks to the high-speed train line being built between Birmingham and London (see “Map”). Major construction projects like the new line, known as HS2, are an ideal opportunity to investigate the buried past. Before building work begins this year, archaeologists will investigate 60 different sites along the 240-kilometre route. The digs will uncover 10,000 years of history, from the time of hunter-gatherers through to the Roman, Saxon, medieval and modern eras. “We expect to find archaeology from every period in our history,” says Mike Court, the lead archaeologist on the project. Here are some of the highlights:

  1. 18th-Century burial ground Birmingham: This Industrial Revolution-era graveyard is thought to hold more than 10,000 bodies, and 1500 have been recovered so far.
  2. Iron age to saxon era site Boddington: Before any digs began, the route of HS2 was surveyed using laser scanners and magnetic detectors. “These techniques give a map of what’s going on underground,” says Court.
  3. War of the roses battlefield Edgecote: The HS2 route runs close to the site of a key battle in the English civil war known as the War of the Roses.
  4. Medieval burial ground St Mary’s Church, Stoke Mandeville: Possibly the most interesting medieval site along the HS2 route is the graveyard of the demolished church of St Mary’s in the village of Stoke Mandeville.
  5. Bronze age dyke, Grim’s Ditch: This long, deep ditch on the outskirts of London is thought to have been constructed in the Bronze Age or Iron Age, but we don’t know why it was built.
  6. Stone age hunter-gatherer site colne valley: The Colne Valley on the outskirts of London may have been an important place for the nomadic hunter-gatherer people living in Britain 10,000 years ago.

116 Evolution News Articles
for January 2019

Evolution News Articles for December 2019