Or a fearsome feline of football?UPDATE: The solutions can be read hereWhen I'm not writing about maths and puzzles, I'm working on my children's book series, Football School, which uses the sport as a lens to the world. Researching the Football School Encyclopedia, the latest book in the series, I discovered the following geometrical curiosity. When painted pitch markings were introduced in 1891, the goal area was in the shape of a B".Goal posts are 8 yards (7.3m) apart. In 1891, goal kicks had to be taken from within 6 yards (5.5m) of either post, so each curved part of the B" is a segment of the locus of a point 6 yards from each post. Continue reading...
Firms with specially trained dogs that can detect infestations are increasingly in demandHotels and homeowners are calling in specially trained dogs to sniff out bedbugs that can lurk in cracks and crevices in bedrooms amid concerns that infestations are on the rise in the UK.The spread of bedbugs declined during the Covid crisis as hotels closed and travel ground to a halt but, since the world reopened, dormant populations have begun to bounce back, if not yet to the level reached before the pandemic. Continue reading...
Up to 20 meteors an hour may be visible as Earth passes through centre of dust cloud left by Halley's cometThe Orionid meteor shower reaches the peak of its activity this week. On the night of 21-22 October, Earth will plough through the central portions of a dust cloud that was once part of the tail of Halley's comet.During the peak of the Orionids up to 20 meteors an hour may be seen from a dark site. The Orionids are so named because they appear to be coming from the Orion constellation. Continue reading...
Our knees, shoulders, necks and hands make all sorts of pops and clicks. Sometimes we even encourage them. But is this the sound of damage being done?When Donald Unger was a child, his mother and several aunts - and later his mother-in-law - told him that cracking his knuckles would lead to arthritis. Rather than stop (or at least do it less obtrusively), Unger embarked on his own experimental programme: for 50 years, he cracked the knuckles of his left hand at least twice a day, leaving his right-hand knuckles to crack spontaneously, or not at all. After 36,500 cracks or so, the results were clear, at least for Unger, who had become a doctor and published his findings in the journal Arthritis and Rheumatism. There was no arthritis in either hand, and no apparent differences between the two hands," he concluded. If you can't applaud Unger for his half-century of dedication, you have to at least respect him for not calling it a cracking" result.Still, voluntary knuckle-cracking is one thing - what about all the other clicks, crunches and crackles that seem to increase in tempo as you start to age? Generally, it's pretty good news. Lots of people have joints that click from time to time, and that's completely normal," says Claire Speer, a physiotherapist and musculoskeletal champion" for the charity Versus Arthritis. I myself often notice a sense of relief when my back or shoulder clicks after stretching or a massage, when everything just feels like it moves a little easier." Continue reading...
The great nature writer and outdoor swimmer has been a huge inspiration to many with his focus on ponds, lakes and riversIt is strange to come to know Roger Deakin so intimately and yet not know him at all. Like many others, I first met him in the pages of Waterlog when I read how he slipped into the spring-fed ditch beside his old farmhouse and swam during a summer thunderstorm.This classic of British nature writing has inspired many of us to swim outdoors and savour the wild world. Possessed of a naturalist's eye for detail and a comic's sense of the ridiculous, he was a warm, witty and welcoming guide as he breast-stroked through the ponds, lakes and rivers of Britain. Continue reading...
Annular solar eclipse passed over eight states from Oregon to Texas and partial eclipse was visible in other continental statesAs the moment of annularity" was reached, photos were snapped, crowds cheered and the sky darkened - in the areas that the annular solar eclipse could be seen, at least.Annularity during a solar eclipse is the moment when the moon is fully in front of the sun, creating the ring of fire that is the visual highlight of today's eclipse. It lasts for only a few minutes. Continue reading...
Tumours reduce with treatment licensed for more common cancersLisa Park was 48 when she was admitted to A&E in 2019 with worsening bouts of abdominal pain. Her eventual diagnosis was unexpected. She was told she was suffering from gallbladder cancer, a rare but serious condition that usually only affects people in old age.Surgery and chemotherapy eradicated the tumours, but after a few months the cancer returned. I was given a year to live," said Park. It was a grim diagnosis, yet her prospects have recently taken an unexpected turn for the better. Continue reading...
Exclusive: Cancer Research UK says toll could be avoided if government tackled health inequalitiesHealth inequalities are causing 33,000 avoidable cases of cancer in the UK every year, a damning analysis suggests.Ministers have promised for years to tackle differences in health outcomes as part of their declared mission to level up the country. But their long-promised white paper on health inequalities has been ditched and the junk food advertising ban on TV and the web has been delayed until October 2025. Continue reading...
Tritylodonts, mid-sized mammal-related herbivores, roamed the area's deserts 200m years agoScientists have discovered an extremely rare" set of fossils at Lake Powell that the National Park Service (NPS) is calling one of the most important vertebrate discoveries in the US this year.The findings, revealed this week, include skulls and teeth from dozens of mid-sized, mammal-related herbivores called tritylodonts that once roamed the region's vast desert. The bones lay hidden in the sandstone walls of the reservoir for roughly 180m years before a lucky discovery in March. Continue reading...
Paul-Henri Nargeolet was onboard the ill-fated submersible that was likely crushed by the ocean earlier this year, killing all five crewThe company that owns the salvage rights to the Titanic shipwreck has cancelled plans to retrieve more artefacts from the site because the leader of the upcoming expedition died in the Titan submersible implosion, according to documents filed in a US district court this week.The decision could affect a looming court battle between the company and the US government, which has been trying to stop the 2024 mission. US attorneys have said the firm's original plans to enter the ship's hull would violate a federal law that treats the wreck as a gravesite. Continue reading...
Scientists believe asteroid may be remains of an early planet's core, and could shed light on inaccessible centers of rocky planetsNasa's Psyche spacecraft rocketed away on Friday on a six-year journey to a rare metal-covered asteroid.Most asteroids tend to be rocky or icy, and this is the first exploration of a metal one. Scientists believe it may be the battered remains of an early planet's core, and could shed light on the inaccessible centers of Earth and other rocky planets. Continue reading...
Some US states will have front-row seats to the celestial event on Saturday - here's what you need to knowSome US cities are over the moon as Saturday's annular solar, or ring of fire" eclipse draws closer, and are gearing up to welcome a rush of visitors. Continue reading...
University of Kentucky challenged computer scientists to reveal contents of carbonised papyrus, a potential treasure trove for historians'When the blast from the eruption of Mount Vesuvius reached Herculaneum in AD79, it burned hundreds of ancient scrolls to a crisp in the library of a luxury villa and buried the Roman town in ash and pumice.The disaster appeared to have destroyed the scrolls for good, but nearly 2,000 years later researchers have extracted the first word from one of the texts, using artificial intelligence to peer deep inside the delicate, charred remains. Continue reading...
by Hannah Devlin Science correspondent on (#6FGXC)
Scientists say challenge of building moon base on dust could be overcome by heating it with giant lensThe moon has no air, no water and an extreme 250-degree temperature range, but among the most vexing challenges for space agencies hoping to set up camp is the dust. It erodes space suits, clogs machinery, interferes with scientific instruments and makes moving around difficult.Now scientists have come up with a potential solution, demonstrating that moon dust could be melted using a giant lens to create solid roads and landing areas. Continue reading...
While timekeepers naturally arrive early, time optimists set off with the assumption the lights will be green and the roads will be empty, getting ever more anxious as the minutes tick away. The good news? Change is possibleThe other day, I was waiting on a train platform, seething with irritation. The service was delayed, which meant I was going to be late meeting a friend at the theatre. It did not help that the venue was on the other side of London. It was one I had never visited before, so I had no idea how long it would take to walk from the station.Running just a wee bit late," I text-fibbed, feeling a rush of remorse. I am not usually spectacularly late, unless I am extremely stressed, and then things turn ugly. I recall the time I had to do an interview with a French actor; unusually, our rendezvous was in the early evening at a cafe. I was already behind schedule and then got hopelessly lost. When I finally turned up, she was blotto, an empty bottle of red in front of her, and furious. More recently, it was the final day of my university degree show and we had to take down our frames by 4pm sharp when the building would close. But I was having a lovely lunch with friends and hadn't noticed the time. At one minute to four, I was racing along the street when I tripped over a paving stone and went flying. That one cost me the use of my shoulder for nine months. Continue reading...
by Presented by Madeleine Finlay, produced by Eli Blo on (#6FGE0)
In 2018 the World Health Organization formally included gaming disorder in its diagnostic manual for the first time. Nearly four years into running the only NHS gaming disorder clinic, Prof Henrietta Bowden-Jones tells Madeleine Finlay about how her team are learning to help those impacted, while a former patient explains how his gaming got out of hand, and how the clinic helped him to regain controlRead more Guardian reporting on this story here Continue reading...
We're racing to keep up with the pace of change as a future arrives faster than we predictedTo protect Antarctica and the Southern Ocean is to protect humanity's future on this planet.That may sound overdramatic - until you appreciate this region's crucial role in the global climate system. Continue reading...
Ancient black dust and chunks are from asteroid named Bennu, almost 60m miles away and collected three years agoChunks of a 4.6bn-year-old asteroid brought to Earth last month show evidence of high levels of carbon and water, Nasa said on Wednesday as the space agency revealed preliminary findings from its pioneering Osiris-Rex mission.Scientists have been analyzing the samples from the asteroid Bennu since they were dropped off by a spacecraft flyby of the Utah desert on 24 September. Principal investigator Dante Lauretta of the University of Arizona, Tucson, told reporters at Houston's Johnson Space Center (JSC) they were scientific treasure". Continue reading...
Conditions such as diabetes and obesity are said to magnify risk of south Asian and black people developing the diseaseThe most common risk factors for dementia appear to have a more pronounced effect in black and Asian people, a study suggests, prompting calls for greater efforts to tackle health inequalities.The number of adults living with dementia worldwide is on course to nearly triple to 153 million by 2050. Experts say the disease presents a major and rapidly growing threat to future health and social care systems in every community, country and continent. Continue reading...
Scientists say trial could pave way for better outcomes for countless individuals' in need of transplantsResearchers have claimed a major step forward in the field of organ transplantation after a monkey survived for more than two years with a genetically engineered pig kidney.The work is the latest to emerge from the US biotech company eGenesis and Harvard Medical School, where scientists see genetically altered pigs as a potential solution to the global shortage of donors for patients with organ failure. Continue reading...
Collision of two ice giant planets produced hot, spinning object potentially hundreds of times the size of EarthThe warm afterglow of a worlds-shattering collision between two massive planets has been seen for the first time after astronomers trained their telescopes on a distant sun-like star.The cataclysmic event is believed to have destroyed a pair of ice giant planets that slammed into one another to produce a shower of debris and a hot, spinning object potentially hundreds of times the size of Earth. Continue reading...
Findings shed light on European common frog's sometimes deadly scramble for a mateWhen it comes to avoiding unwanted male attention, researchers have found some frogs take drastic action: they appear to feign death.Researchers say the findings shed new light on the European common frog, suggesting females do not simply put up with the male scramble for mates - a situation in which several males can end up clinging to a female, sometimes fatally. Continue reading...
Innovative scanning techniques show painting of sculptures was potentially as intricate as their carvingThough the Parthenon marbles were admired for centuries for their stark white brilliance, it has long been known that the sculptures were originally brightly painted, before millennia of weathering, cannon bombardment, rough handling and overenthusiastic cleaning scoured them clean.Evidence for the paintwork has been highly elusive, however, leading their former curator at the British Museum to confess that, after years of hunting in vain for traces of pigment, he had sometimes doubted they were painted at all. Continue reading...
by Hannah Devlin Science correspondent on (#6FEW6)
Research shows birds with small alterations to one gene are highly resistant to avian fluScientists have created the world's first flu-resistant chickens in an advance that could pave the way for gene-edited poultry on UK farms.The birds, which had small alterations to one gene, were highly resistant to avian flu, with nine in 10 birds showing no signs of infection when exposed to a typical dose of the virus. Continue reading...
There's something to the notion that Nobel winners create less thereafter. But it is life-changing, and it truly helps to get things doneTwenty-two years ago, I was in a room in London talking about setting up a museum to celebrate the monk Gregor Mendel, the founder of genetics. Someone came in and gave me a note from my lab saying I should turn on my mobile phone. A heavily distorted message had been left, and it sounded like a journalist asking me for comments on the Nobel prize in medicine, which he said had been awarded that day to my friend Tim Hunt. I listened to it again and then a third time. Was he also saying I had won it too? I returned to the room and said something that in retrospect must have sounded very strange: I must go now because I think I may have won a Nobel prize." It was true, I had won it, together with Tim and Leland Hartwell, a scientist from Seattle, for our work on how cells control their division.The prize changed our lives. It is the one scientific prize everyone knows. Suddenly you become a public figure being asked to do all sorts of things: to give lectures, quite often on topics you know little about; to sit on committees and reviews you are not always well qualified to be on; to visit countries you have barely heard of; to sign endless petitions on what are probably good causes, but you never know. It is like having a whole new extra job, with upwards of 500 requests a year. It is impostor syndrome on steroids.Sir Paul Nurse is director of the Francis Crick Institute and chancellor of the University of Bristol. He was awarded the Nobel prize for physiology or medicine in 2001 and the Royal Society Copley medal in 2005 Continue reading...
by Presented and produced by Madeleine Finlay with An on (#6FEE7)
The Guardian's Paris correspondent, Angelique Chrisafis, tells Madeleine Finlay about the explosion in bedbug sightings in the city, and how residents and officials have reacted. And Prof Jerome Goddard explains what makes the creatures so difficult to eradicate, and why the biggest threat they pose may be to our mental healthClips: Tiktok, ITV, NBC, LeFigaroRead more Guardian reporting on this story. Continue reading...
Report's authors also estimate about 12% of children hooked and call for further research into problemOne in seven adults and one in eight children may be hooked on ultra-processed foods (UPFs), experts have said, prompting calls for some products to be labelled as addictive.Recent studies have linked UPFs such as ice-cream, fizzy drinks and ready meals to poor health, including an increased risk of cancer, weight gain and heart disease. Global consumption of the products is soaring and UPFs now make up more than half the average diet in the UK and US. Continue reading...
Roscosmos says temperatures in affected unit normal after flakes of frozen coolant seen in live feedThe Russian segment of the International Space Station (ISS) has sprung its third coolant leak in under a year, raising new questions about the reliability of the country's space programme even as officials said crew members were not in danger.Flakes of frozen coolant spraying into space were seen in an official live feed of the orbital lab provided by Nasa on Monday, and confirmed in radio chatter between US mission control and astronauts. Continue reading...
Analyst and psychiatrist who proposed a science of human nature that embraced psychology, anthropology and medicineThe analyst and psychiatrist Anthony Stevens, who has died aged 90 after suffering a stroke, was distinctive among followers of Carl Jung in looking to evolutionary theory for a basis for the idea of a collective unconscious and archetypes affecting development and behaviour in the individual psyche. Rather than extending the archetypal concept upwards towards a spiritual dimension and inwards into the realm of inner psychic life, Anthony traced it to its biological roots and outwards into the realm of social behaviour.In his first book, Archetypes: A Natural History of the Self (1982), he compared the findings of behavioural biology with those of analytical psychology - the term that Jung used to distinguish his approach from the psychoanalysis of Sigmund Freud - in order to illuminate the ways in which the so-called archetypes of the collective unconscious might influence human development in fundamental areas. Continue reading...
Goalies' brains appear able to merge signals from different senses more quickly, say researchersThe former Premier League goalkeeper Brad Friedel once said that to be able to work well in the box, you have to be able to think outside the box.Now scientific data supports the idea that goalies' brains really do perceive the world differently - their brains appear able to merge signals from the different senses more quickly, possibly underpinning their unique abilities on the football pitch. Continue reading...
Scientists find feline low register when signalling pleasure is produced in a similar way to the croaky voice of some singersScientists have cracked the mystery of how cats produce the purring sound that signals their approval. It turns out they use a strikingly similar technique to vocal fry" - the croaky voice used by the singer Katy Perry and reality television star Kim Kardashian.Researchers have long puzzled over how an animal as small as a domestic cat can produce the deep resonance of a purr, when such vocalisations are usually only produced by animals with far longer vocal cords, such as elephants. For many years, they believed purrs were produced using a unique mechanism that involved the cyclical contraction and relaxation of muscles in the voice box - something that would require constant neural input from the brain. Continue reading...
Experts uncover 17th-century coins at site linked with clan chief Alasdair Ruadh Maclain' MacDonaldA hoard of coins linked to a Highland chief - which may have been stashed away as he tried in vain to escape the Glen Coe massacre - has been discovered underneath a fireplace.The 17th-century collection of 36 coins included international currency, and was hidden beneath the remains of a grand stone fireplace at a site believed to have been a hunting lodge or feasting hall. Continue reading...
Early risers across the world can witness the alignment, while an annular eclipse can be seen from the AmericasEarly risers are in for a treat this week, as a beautifully thin waning crescent moon lines up with the bright star Regulus, in Leo, and the brilliant jewel of Venus.The chart shows the view looking east from London at 5am BST on 10 October. The moon will have just 18% of its visible surface illuminated. The alignment can be seen across the world at a similar time, although from places like Cape Town, South Africa, and Sydney, Australia, the triplet will rise in the pre-dawn skies, making Regulus a little trickier to spot. Continue reading...
Excavations reveal structure that may be one of a kind below building that was used for range of leisure activitiesThe therapeutic value of ice baths or cold water immersion were recognised long before wellness gurus and celebrities extolled them on social media. Even the Romans were fond of a dip in the frigidarium.Now it has emerged that the men and women of 18th-century Bath could visit their local assembly rooms for an icy plunge, alongside indulging in other leisure and pleasure pursuits. Continue reading...
I travelled to Nordic forests and windswept archipelagos to understand the health benefits of the sauna - no wonder it's becoming popular in the UKAs I squeeze myself on to the top bench of the sauna in my local lido, I'm grateful to have a spot. It's rammed; standing room only. Next to the stove, cold water swimmers huddle and struggle to peel neoprene off shivering hands and feet, their teeth chattering. In fact, everyone is chattering. It's as noisy as the pub before closing time and as ebullient; a steamy collective fuelled by extremes of temperature rather than extremely large amounts of booze. But, unlike the pub, everyone is semi-naked, sweating and stripped back - job title, wealth, celebrity and status left firmly by the pool.Since we opened the sauna at Parliament Hill Lido six years ago, we have seen visitor numbers shoot up," says Paul Jeal, swimming facilities manager at Hampstead Heath for the Corporation of London. Once deserted and running at a loss in winter, the lido now sees queues at weekends and Jeal has to manage sell-out sauna sessions of 30 tickets an hour. Since Covid, visitor numbers have increased fourfold," he adds. Many are new to cold water swimming and they say the sauna has encouraged them to come." In spring, the sauna benches collapsed from heavy use. Continue reading...
As virus cases rise by 30% in the past week, the clinically vulnerable and medics fear they will be put at risk this winterHealthcare charities and patient groups are calling on NHS England to reintroduce Covid-19 precautions for staff, amid fears that clinically vulnerable patients and medics will be put at risk this winter.Since Covid safety measures were dropped earlier in the year, staff in NHS England are no longer required to wear a mask in clinical settings. Most healthcare workers who have symptoms of a respiratory infection are no longer asked to test for Covid. Continue reading...
The luxury fashion brand announced a collaboration with Axiom Space to outfit astronauts for the 2025 mission to the moonPrada will take its designs to the next atmospheric level as the Italian fashion house announced its latest partnership with Axiom Space to design spacesuits for astronauts.This week, the Milan-based luxury brand announced its collaboration with the Texas-based commercial space company to design Nasa's lunar spacesuits for its 2025 Artemis III mission - the first crewed flight to the moon since Apollo 17 in 1972. Continue reading...
Ahead of the organisation's report into the state of our flora and fungi, its director of science talks about his work as a biogeographer and how our diet can make a differenceAlexandre Antonelli is director of science at the Royal Botanic Gardens, Kew, and a professor of systematics and biodiversity at the University of Gothenburg, Sweden. He spoke to the Observer ahead of this week's launch of the organisation's seminal report The State of the World's Plants and Fungi, which last took stock in 2020. He is also the author of The Hidden Universe: Adventures in Biodiversity (Ebury Press, 14.99).What do you do at Kew - what are the best and the worst things about your job?
Quantum computers may still be years away, but it's prudent that end-to-end encryption providers are ramping up defencesA spectre is haunting our networked world. It's the prospect of quantum computers. These are machines that harness some of the weirder properties of subatomic particles in ways that would make them exponentially more powerful than the computers we use today.Existing computers are based on manipulating digital bits that can be either 1 (on) or 0 (off). Quantum machines, in contrast, work with qubits, which can be on and off simultaneously. (And, yes, I know that seems nuts, but then so does much of subatomic physics to the average layperson.) Such machines are fiendishly difficult to build, but about 80 or so small-scale ones already exist, with qubit counts ranging from five to 400. So that looming spectral presence is beginning to put on weight. And if researchers find a way of reliably scaling up these machines, then we will have moved into uncharted territory. Continue reading...
We asked experts in teen mental health how to talk about everything from the environment to screen time with adolescentsCommunication is one of the biggest issues when you've got a teenager. Conversations can be fraught, loaded - they often feel as if they're about to go ballistic - or worst of all, they're just nonexistent. Your teen seems to be a closed book - they don't want to talk and you don't seem to be able to coax them out of their shell.And yet there are effective ways to open up a conversation with your teenager - though you need to be very sensitive, and self-aware, and genuinely interested in creating a dialogue rather than just a chance to ram home what you think about an issue. Continue reading...
More resilient variants are emerging. Yet monitoring and testing have slowed, and access to vital drugs is patchyIt may feel like we should all be done with Covid-19, but sadly Covid-19 is not done with us. At the moment, cases in England are rising again, with a 10% rise overall in hospital admissions and the greatest increase in the north of England. With testing reduced, national monitoring paused, the ONS infection survey paused since spring and only recently relaunched, we have much less data about Covid than we ever had before. We know Covid hasn't stopped evolving, and we have a good idea about what sort of situations might result in new and dangerous mutations, but with less surveillance of emerging variants and spread, we are losing what used to be a near real-time picture of the situation.This makes it harder to know which variants are driving the increase in cases. The latest estimates suggest there is a soup, with several variants, including some derived from XBB, which emerged last year, as well as EG5.1 (Eris) and a small amount of BA.2.86 (Pirola), both of which were identified in the past few months. It seems as though this virus is ever-changing, and as a reflection of that, new data released in the last few days shows that the so-called Pirola variant has evolved again - and could be more immune-evasive than the XBB-derived variants.Sheena Cruickshank is an immunologist and professor in biomedical sciences and public engagement at the University of Manchester Continue reading...
Startup PLD Space says launch of Miura-1 is just the beginning' amid European drive to send satellites into orbitSpanish company PLD Space launched its reusable Miura-1 rocket early on Saturday from a site in south-west Spain, carrying out Europe's first fully private rocket launch and offering hope for its stalled space ambitions.The startup's test nighttime launch from Huelva came after two previous attempts were scrubbed. The Miura-1 rocket, named after a breed of fighting bull, is as tall as a three-storey building and has a 100kg (220-pound) cargo capacity. The launch carried a payload for test purposes but this would not be released, the company said. Continue reading...
Amazon launched its first two prototype satellites into space on Friday, as Jeff Bezos's tech firm races to compete with Elon Musk's SpaceX in building a mega-constellation of broadband internet-providing satellites. The duo, called Kuipersat-1 and Kuipersat-2, will be deployed in an orbit 311 miles above Earth's surface
Pioneering physician who promoted and brought rigour to the new field of audiovestibular medicineWhen Linda Luxon, who has died aged 75 of a brain tumour, began her medical career, few had heard of audiovestibular medicine". First recognised as a medical specialty in 1975, it treats a wide range of disorders that affect hearing and balance. The vestibular system controls balance and spatial orientation through organs located in the vestibule, a bony cavity of the inner ear. These organs detect head movement and send signals to the brain so that we stay upright and balanced. When the system malfunctions, dizziness, vertigo and tinnitus can result.According to her close colleague Doris-Eva Bamiou, Luxon became the specialty's pioneer and poster child", giving it academic rigour and promoting it widely. In 1991 she was appointed professor of audiovestibular medicine at University College London (UCL). There she anchored the new specialty in evidence-based research, systematically delineating all the different disorders and setting criteria for diagnosis. She wrote or co-authored a number of key reference titles and more than 175 research papers. Continue reading...
Fossil footprints date back to between 21,000 and 23,000 years ago, upending previous theory that humans reached continent laterNew research confirms that fossil human footprints in New Mexico are probably the oldest direct evidence of human presence in the Americas, a finding that upends what many archaeologists thought they knew.The footprints were discovered at the edge of an ancient lakebed in White Sands national park and date back to between 21,000 and 23,000 years ago, according to research published on Thursday in the journal Science. Continue reading...
Science | The Guardian