Sommaire pour October 2021 de BBC Science Focus Magazine

Microbiomes and missing gnashers In August’s issue you reported that Dr Bei Wu and colleagues had found a link between tooth loss and declining cognitive function (p20), speculating that difficulty chewing leads to nutritional deficiencies in the brain. There may be an additional factor to consider: the gut-brain axis. Without dentures, people may avoid foods that require considerable chewing, such as nuts or high-fibre fruits and vegetables. As these foods aid intestinal bacteria, which play a key role in the gut-brain axis, this would ultimately affect behaviour and cognition. It would be interesting to analyse the participants’ microbiome and, perhaps, monitor how the results are affected by introducing foods that benefit the gut. Georgina Hawkins (age 14)…

It’s widely known that as we age our immune systems become weaker and slower to respond to infection, leaving us at a greater risk of becoming ill. But when it comes to developing genetic diseases, the risk of us getting ill actually wanes with age, a study carried out at the University of Oxford has found. We each inherit half of our genes from our father and half from our mother. Our genes play a huge role in our appearance and development – from our hair colour to our height – but also influence our risk of developing all manner of diseases such as cancer and heart disease. By using genomic data taken from 500,000 people and stored in the UK Biobank, the researchers were able to look for the…

When hunting for signs of life on other planets, astronomers have typically played it safe. They’ve looked for Earth-sized planets, with Earth-like surface temperatures, and Earth-like atmospheres. But now, a team of researchers from the University of Cambridge have identified a new class of habitable planets that could change the game completely. Dubbed ‘hycean’ planets – a portmanteau of ‘hydrogen’ and ‘ocean’ – these newly identified exoplanets are more numerous and easier to spot than Earth-like planets. According to the researchers, specifically hunting for hycean planets could lead to us discovering biosignatures of life outside our Solar System within the next two or three years. “Hycean planets open a whole new avenue in our search for life elsewhere” “Hycean planets open a whole new avenue in our search for life…

I am a big fan of the Mediterranean diet, which is rich in oily fish, nuts, vegetables and legumes (such as lentils and red kidney beans). There’s a lot of research showing that this way of eating reduces your risk of heart disease and type 2 diabetes. And we also know that switching from a typical Western diet to a Mediterranean diet can be an effective way to improve your mental health, with studies showing that it reduces rates of anxiety and depression. But there are a couple of downsides to the diet. Anyone who’s started eating more fibre-rich food (or fermented foods, such as sauerkraut) will know that you soon start producing much larger stools and far more wind. Now, thanks to scientists from the Liver and Digestive Diseases…

I ABSOLUTELY LOVE PICKING MY NOSE AND EATING BOGIES! BUT WILL THIS MAKE ME ILL? We’ve all watched distastefully as our toddlers’ fingers creep towards their nose, dig around for a bogie, and whip it into their mouth. Of course, we would never do that ourselves. Not even when our cameras are turned off during a video conference. Never. The technical name for bogie-eating is mucophagy, and when it becomes a true, obsessional habit, it is known as rhinotillexomania. But is this behaviour safe? After all, bogies are made of bacteria, viruses and dirt that get trapped by the little hairs and mucus in your nose. Some argue that eating them might be good for us. The ‘hygiene hypothesis’ is a theory that early exposure to germs and certain infections…

HOW CAN I SEE THE DRACONID METEOR SHOWER? WHEN: 7-11 OCTOBER Meteor showers occur when Earth passes through a trail of debris that has been left behind by a passing comet or asteroid. As these remnants – mostly the size of a grain of sand – enter Earth’s atmosphere, they create bright streaks across the sky as they burn up. With two meteor showers, October is the perfect time to wrap up, grab a hot drink, and lie back to enjoy the show, preferably somewhere dark (it will take about 15 minutes for your eyes to adjust). The Draconid meteor shower is visible between 7-11 October, peaking on the night of 8 October. Sometimes known as a ‘minor’ shower, it may only produce about 10 meteors an hour, although it…

KAMILA MAGMEDOVA, AGED 14 DO HUMANS HAVE A GENETICALLY INHERITED PREFERENCE FOR TASTE? We do. Thanks to studies monitoring identical twins, and surveys of gene data from personal genomic companies, we know that there are genes that affect our sense of taste, our sense of smell, and even the reward centres in the brain. For instance, our likelihood of thinking that coriander tastes soapy is thanks to the variant of the odour receptor gene OR6AS that you inherit. Genes can influence whether you can taste the bitter compound phenylthiocarbamide or not (about 30 per cent of Europeans have the variation of the taste receptor gene TAS2R38 that makes them ‘taste blind’ to this cabbage flavour). Even the extent to which your brain’s reward centres respond to bacon could come down…

ACROSS 1 Mark, struck by drummer, say (6) 5 Heard directors were fed up (5) 9 Investigator is nasty about getting a student (7) 10 Jelly for crawler in charge (5) 11 Fool caught inside hill (5) 12 Treated a mad one, but it’s benign (7) 13 Adapt medium, sick of DIY (6) 15 Coach let off in rush (6) 18 Charm of French illumination (7) 20 Horrify a quiet friend (5) 23 Big look around the house (5) 24 Digital audio file about cod in former time (7) 25 Pale, like a farm animal (5) 26 Creature is wild, not red (6) DOWN 2 Deserve sticky end before ache (5) 3 Flavouring used by a flea (3,4) 4 Allow Harold to be mortal (6) 5 Support a couple (5)…

Nature And Us What can history’s greatest artworks reveal about the state of the Earth? This new series, presented by James Fox (pictured) explores our relationship with the natural world, as told by prehistoric cave paintings through to modern art. BBC Four Available from 11 October Bad People In the new series of this podcast, criminal psychologist Dr Julia Shaw and comedian Sofie Hagen are back to cast a forensic eye over some of the most shocking, intriguing and unimaginably criminal acts. BBC Sounds Released throughout October The Life Scientific Prof Jim Al-Khalili is joined by a fantastic panel of guests for the 10th anniversary of The Life Scientific. Paul Nurse, Ottoline Leyser, Christopher Jackson and Hannah Fry (pictured) are just some of the experts joining him for the decade’s…

Each year more than 17,000 people aged 45 and over are diagnosed with Parkinson’s disease in the UK. Worldwide, neurological disorders are the leading cause of disability, and Parkinson’s disease is the fastest growing among them. Parkinson’s is a progressive neurological disease that affects a person’s nerve cells, leading them to suffer from tremors, muscle stiffness and slowness of movement. There is currently no known cure. Much of the previous research on Parkinson’s has relied on the use of mice, which doesn’t allow scientists to study all of the effects of the disease. Now, researchers from the Agency for Science, Technology And Research (A*STAR)’s Genome Institute of Singapore (GIS), the National Neuroscience Institute (NNI) and Duke-NUS Medical School have discovered a way to produce mini brains that mimic the physiological…

Increase your fibre intake Aim for more than 40g per day – about double what the average person consumes. Wholegrains, pulses and veg are good sources. Eat a wide variety of fruit and veg Variety is important, as the chemicals and types of fibre will be different, and each support different microbial species. Choose food and drinks with high levels of polyphenols Polyphenols are fuel for microbes. Nuts, seeds, berries, olive oil, coffee and tea are good sources. Avoid artificial sweeteners such as aspartame These disrupt the metabolism of microbes and reduce gut diversity. Stroke animals Studies have shown that people living with dogs have more microbial diversity.…

Whether it’s a black Americano, a strong espresso, or a triple venti no foam soy milk latte with an extra shot, drinking your daily cup of Joe may help to lower your risk of stroke and fatal heart disease. Researchers at the Heart and Vascular Centre, Semmelweis University, Budapest, Hungary, have found that drinking up to three cups of coffee a day may help protect your cardiovascular system. The team studied data from nearly 500,000 people registered in the UK Biobank with an average age of 56 and no signs of heart disease at the time of recruitment. They divided them into three categories according to their coffee habits – non-drinkers, up to three-cup-a-day drinkers, and more than three-cup-a-day drinkers. When adjusted for influencing factors such as age, sex, weight,…

As photography subjects go, birds are notoriously flighty. So it’s not hard to admire the work on show at the Bird Photographer of the Year contest. The winners of the 2021 prize have been announced, narrowed down from a flock of 22,000 entries. See some of the winners on these pages, and explore more incredible entries at birdpoty.com 1. Bronze Award Winner, 9-13 years by Ian Henderson A woodpecker finch uses a small twig to fish insects out of a piece of rotten wood in the Galapagos Islands. 2. Bronze Award Winner, 14-17 years by Daniel Zhang Although it seems that the toad is jumping into the hamerkop’s mouth, the bird is actually throwing its prey around to kill it. The photo was snapped in Zimanga Private Game Reserve, South…

It may seem an obvious outcome of a pandemic where social contact is discouraged, even made illegal, but concerns about rising levels of loneliness were common before the coronavirus and will likely persist for the foreseeable future. Humans are an incredibly social species. It’s one of the reasons we have such powerful brains and advanced intelligence – to better keep track of and maintain numerous relationships. Our social interactions are a huge factor in how we think, act and see ourselves, because much of our brains are dedicated to social cognition. Completely depriving someone of human contact is a recognised form of torture. Human wellbeing depends on interpersonal interactions and relationships. It’s no wonder that prolonged loneliness is associated with many serious health consequences, such as an increased risk of…

Of the many problems climate change poses, rising sea temperatures have the potential to be the most catastrophic. Warmer oceans mean rising sea levels, melting ice caps and more extreme weather events, including hurricanes. But a Norwegian company claims to have a way to mitigate that last one. OceanTherm, founded by Olav Hollingsaeter, a former naval officer, is developing a system that uses bubbles to cool the sea’s surface by drawing up cold water from the depths. Hurricanes are created when hot and cold air meet over warm ocean waters of 26.5°C or above. The warmer the water, the more powerful a hurricane can become. But water below 26.5°C has neither the heat nor sufficient levels of evaporation to feed a hurricane, and so will reduce its strength. OceanTherm’s idea…

It sounds like the stuff of dreams: a virtually limitless source of energy that doesn’t produce greenhouse gases or radioactive waste. That’s the promise of nuclear fusion, which for decades has been nothing more than a fantasy due to insurmountable technical challenges. But things are heating up in what has turned into a race to create what amounts to an artificial sun here on Earth, one that can provide power for our kettles, cars and light bulbs. Today’s nuclear power plants create electricity through nuclear fission, in which atoms are split. Nuclear fusion however, involves combining atomic nuclei to release energy. It’s the same reaction that’s taking place at the Sun’s core. But overcoming the natural repulsion between atomic nuclei and maintaining the right conditions for fusion to occur isn’t…

THE STRESS RELIEVER Mycobacterium vaccae was discovered on the shores of Lake Kyoga in Uganda in the 1970s by John Stanford, an immunologist. Today, Dr Chris Lowry, a neuroscientist at the University of Colorado Boulder, has shown that this bacterium can reduce stress and anxiety – in mice, at least. Part of this effect is due to the bacteria controlling the expression of the gene tph2, which causes more of the mood-stabilising neurotransmitter serotonin to be produced. THE IMMUNE BOOSTER Bacillus subtilis is found in soil, and tests in animals have found it can supercharge their immune systems, boosting the antibodies in their circulation and increasing their ability to fight off infections such as Salmonella. This microbe is already being used for good as it produces the antibiotic bacitracin, which…

HOW CAN SMART TECH TACKLE CLIMATE CHANGE? The recent 2021 IPCC report declared a code red for humanity, with 2019’s atmospheric CO2 concentrations higher than at any time in at least two million years. Our only chance of averting irreversible climate change is to reduce our carbon, methane and nitrous oxide emissions to net zero. And one way we can achieve this is by making our technologies more sustainable. For instance, we can embed artificial intelligence into our buildings and let them reduce power to lights, ventilation or lifts that are not in use. Zero-emission electric cars will also have AIs to assist our driving, making them safer and more efficient. Home energy storage solutions mean that power from solar panels can be stored, bringing us towards a distributed power…

Since the discovery of penicillin by Alexander Fleming in 1928, bacteria have constantly evolved new ways to resist the effects of antibiotics. Currently more than 50,000 people die in Europe and the US every year from infections that don’t respond to conventional antibiotic treatments. If current trends continue, all of our antibiotic medicines could become ineffective within the next few decades. One way of potentially countering this trend is to use bacteriophages – naturally occurring viruses that are capable of killing bacteria. Now, a team of researchers from the Université de Montpellier, France, and the University of Pittsburgh, USA, have discovered that combining bacteriophages with conventional antibiotic treatments could make them even more effective at slaying bacteria. “Fish treated with ‘Muddy’ had less severe infections” The team decided to focus…

Just when you thought that the king of the dinosaurs couldn’t get any more terrifying, a study by Japanese researchers has found that T. rex may have been able to pick out the most desirable, tastiest parts of its freshly killed prey. A team of researchers based at the Institute of Dinosaur Research in Fukui Prefectural University, Japan, used computed tomography (CT) scanning techniques to reconstruct the complex structure of blood vessels and nerves found in the mandible of a T. rex fossil originally unearthed in Hell Creek Formation, Montana. By comparing their data to scans of other dinosaurs such as Triceratops, along with currently living birds and crocodiles, they were able to determine that T rex had nerve sensors in the tip of its jaw that enabled it to…

There are currently five species of rhinoceros living on Earth: Indian, Javan, Sumatran, white and black. But piecing together exactly how they are related has proven problematic, thanks to a lack of genetic data. Now, a study by an international team of researchers has helped to fill the gaps in the rhino evolutionary family tree by analysing and comparing the genomes of all five living species along with the genomes of three extinct species – woolly, Merck’s, and the Siberian unicorn. “We can now show that the main branch in the rhinoceroses’ tree of life is among geographic regions, Africa versus Eurasia, and not between the rhinos that have one versus two horns,” said study author Love Dalén of the Centre for Palaeogenetics and the Swedish Museum of Natural History.…

PAUL BYRNE Planetary scientist There are some topics that elicit strong opinions from people. Is Die Hard a Christmas movie? (Yes.) Does pineapple belong on pizza? (Also yes.) Is Pluto a planet? I say that it is. But this isn’t a view that’s universally held. Those of us born in the latter part of the 20th Century grew up learning that there are nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, in increasing distance from the Sun. But in 2006, the International Astronomical Union (IAU) – the entity charged with, among other things, deciding what to call stuff in space – held a vote that overnight reduced the number of planets in the Solar System to eight. From its discovery in 1930 until the 1990s, Pluto…

It’s almost a cliche for people to talk about how we’ve all become narcissists, because social media has turned us into selfie-obsessed, image-crafters. This is particularly assumed to be the case for the ‘me, me, me’ generation: millennials. But, are we more narcissistic today, or is this just the age-old scepticism about ‘kids these days’ built on stereotypes and misplaced nostalgia? First of all, what is narcissism and is it inherently bad? In May 2021, Ohio State University academics Sophie Kjærvik and Prof Brad Bushman published a review of 437 studies on narcissism, which together included 123,043 participants. In it, they defined narcissism as “entitled self-importance”, explaining that “people with high levels of narcissism think they’re special people who deserve special treatment. They have an exaggerated and inflated sense of…

Just how happy can a child make you? The answer, it turns out, could depend on where you live. At least that’s according to a major study of 22 countries that compared the happiness of adults with and without children. By using a survey to score people’s general happiness levels – rather than just asking about a parent’s satisfaction with having children – researchers from the University of Texas concluded there was a significant ‘happiness gap’ between the two groups. Which group was better off varied between countries, with parents in nations such as the UK being more than 8 per cent less happy than non-parents on average. This gap widens to 12 per cent in the US. However, this ‘parental happiness deficit’ doesn’t occur everywhere. Parents in some countries…

WHAT CAUSES EARTH’S MAGNETIC FIELD? Magnetic fields are generated by electric charges in motion. In a bar magnet, the moving charges are electrons orbiting in atoms. In the Earth, they are electrons ferried around by circulating currents of molten iron. The details are not well understood. But, basically, hot material in Earth’s outer liquid iron core expands, becoming less dense than its surroundings, and therefore rises. Cooling and becoming less dense, it should sink back down again. But the Earth’s rotation prevents this. Consequently, liquid circulates around the core, and friction between its different layers charges them up – just like a plastic comb rubbing against a nylon sweater. It’s these moving charges that generate the Earth’s magnetic field. The two requirements for planetary magnetism are therefore a liquid core…