Study may help diagnose and identify people at risk of developing Alzheimer’s much earlierHumans can make fresh brain cells until they are well into their 90s, but the production of new neurons falls in those with Alzheimer’s, even when the disease has recently taken hold, scientists have found.The findings may help doctors to diagnose Alzheimer’s at an earlier stage, and identify those most at risk who may benefit from exercise and other interventions that could boost the production of new brain cells. Continue reading...

Trial of once-daily capsule appeared to reduce sperm count with few side-effectsHopes for a male contraceptive pill have increased after a trial showed a once-daily capsule appeared to work with no significant side-effects.The drug aims to suppress levels of hormones that drive the production of sperm and testosterone in the testes. Continue reading...

Project Mission Jurassic will excavate land in Wyoming where brachiosaurus and diplodocus have been unearthed

Decades of studying primates has convinced me that animal politics are not so different from our own – and even in the wild, leadership is about much more than being a bully• Read the text version here Continue reading...

A celebration of the number that’s one more than tenUPDATE: Solution is now posted hereLegs eleven, Ocean’s Eleven, elevenses!Yes, let’s hear it for the number 11, star protagonist of today’s puzzles. Continue reading...

Charmouth, Dorset: The eroding cliffs spill ammonites back into the sea, while fossil hunters filter along the beachThe crashing waves throw up a misty-grey haze as they break against the bottom of crumbling ashen cliffs that slouch on to the top of the beach. The backdrop is the imposing hulk of Golden Cap, its sandstone-topped, ragged, seaward face cascading at 45 degrees for 200 metres to meet the churning waters.Related: To collect or not to collect: are fossil-hunting laws hurting science? Continue reading...

After the half-moon on Thursday, when the moon will be between Saturn and Jupiter, the waning crescent will gradually disappear from viewFollowing last week’s full moon, this week our nearest celestial neighbour crosses from waning gibbous moon to waning crescent moon. It does that in the company of two giant planets, making it an attractive sight for those awake in the pre-dawn hours. The chart shows the view looking south-south-east at 0400 GMT on 28 March. The visible surface of the moon will be precisely half lit, a configuration called last quarter. This marks the boundary between waning gibbous and waning crescent phases. On 28 March, the last quarter moon will appear in the constellation Sagittarius. The moon will be equidistant from Saturn, to the lower left, and Jupiter, to the upper right. Saturn will be the dimmer of the two planets. It will appear as a yellow colour. Jupiter will be higher in the sky, brighter and a white colour. In this final week of the lunar cycle, the Moon rises later and later, eventually disappearing from view into the dawn glow. From here it will reappear as a young moon a few days later, and the next lunar month will begin. And don’t forget that British Summer Time begins this week at 0100 on Sunday, 31 March. Continue reading...

Statisticians are calling on their profession to abandon one of its most treasured markers of significance. But what could replace it?Statistical arguments are a crucial part of decision-making in a modern society. The kind of decisions that governments and large companies must make all the time are governed by probabilities. In those circumstances of uncertain knowledge we need to reduce a cloud of unknowing to facts as hard and cold as hailstones that can be acted on, or even just used in arguments. But some of the most popular techniques for doing this are now under attack from within the profession.The p value is supposed to measure whether the conclusions drawn from any given experiment or investigation of data are reliable. It actually measures how unlikely the observed result is compared with what would be expected as a result of random chance. Obviously this requires a sophisticated understanding of the results that chance might be expected to produce. This isn’t always available. To take one popular example, any calculation of how likely we are to be the only intelligent species in the universe depends absolutely on assumptions about the likelihood of intelligent species arising, which can’t be tested across a range of universes. Continue reading...

Bonnie Wortmeyer is one of thousands finding freedom from Clostridium difficile bacteria through faecal microbiota transplantationBonnie Wortmeyer has spent the past few years plagued by ill health. Among the major issues she has had to deal with are a double lung transplant and what she calls her “poo transplant”, which she says changed her life.While recovering from her double lung transplant, Wortmeyer was exposed to numerous courses of antibiotics, which made her susceptible to contracting the Clostridium difficile bacteria. C diff, as it’s known, is a nasty, life-threatening bacteria which makes life almost unbearable for its sufferers. Continue reading...

Regulation has been unscientific and too restrictive. But the spectre of psychosis means some will always have to be waryOccasionally during my love affair with marijuana I would experience perceptual disruptions profound enough to freak me out. One time I was driving along a crowded road when my car seemed a little wobbly and then listed towards the centre, an alarming thud-thud emanating from the back end. In the middle of a densely populated spot without a hard shoulder, I crept slowly across a few lanes of traffic and pulled to a stop. Concentrating very hard, I got out of the car to assess and hopefully change the flat tyre. I rarely got paranoid from smoking weed; neither did it typically make me sleepy. Instead, I was among the lucky ones, as the drug made everyday activities such as gardening, waiting on tables and talking to my family bearable if not interesting. So I was shocked and embarrassed to find, after a few minutes of close inspection amid the honking horns, that there was nothing wrong with the car.At the time I took hallucinations as evidence of a good score. Now, as an ex-smoker and neuroscientist whose focus is addictive drugs, I know that my resilient response to this stressful experience was contingent on having a neurotypical brain. Neural pathways are forged by finely orchestrated signals for synapse growth and pruning; disruptions can result in atypical neural connections that increase the risk of psychosis. The liability may be unmasked by environmental conditions that can essentially be reduced to an ambiguous but well-recognised bogeyman: stress. Continue reading...

One of my colleagues is roused to volcanic harrumphing by the tangible outcomes of insidiously intangible infelicitiesFor some people, it’s the little things that truly offend; sins against the English language that cause them to believe that the whole glorious edifice is crumbling. One of my colleagues is roused to volcanic harrumphing by the use of the word “multiple”. He might like to avert his gaze now.“Exercise program provides multiple benefits to nursing home residents”; “multiple churches burglarized in Back of the Yards: police”; “Sussex TK Maxx thefts – man charged with offences at multiple stores”; “Multiple animals killed in South Jersey barn fire”. Continue reading...

A version of the club drug licensed in the US could usher in a wave of fast-acting treatments, but experts are worriedClaudia Kieffer remembers the first time she encountered the drug she describes as having “saved my life”. Eight years ago, Kieffer, who had suffered from treatment-resistant depression for decades, was given ketamine as a routine anaesthetic, as part of a post-mastectomy breast reconstruction procedure.But as well as alleviating the pain, Kieffer noticed an instantaneous change in her state of mind. Continue reading...

His new show, After Life, divides opinion, except in my householdI kept walking in on my partner last week quietly crying over the laptop. Not, as might be reasonable to expect, because she is stuck in an infinite current affairs loop, never knowing when she might be freed from the horrors, but because she has been watching Ricky Gervais’s new sitcom, After Life, on Netflix. “You’re not allowed to watch it with me,” she said, pointedly closing the lid. “I’m enjoying it and you’ll ruin it. Go somewhere else.”Rude, I thought, and then said something about how the reviews hadn’t been very good anyway, which only proved her point. The reviews I read have not been particularly kind, it’s true, but already After Life seems to have reached Bohemian Rhapsody levels of division between what critics have made of it and what real-life viewers think. On a recent episode of Gogglebox, the families who do not usually agree on what they’re watching all collapsed into paroxysms of laughter at a gag about Gervais’s character, Tony, being called a “paedo”. Continue reading...

A week in Wales with a lifeboat of fellow passengers reaps surprising resultsI am stretched out on a mattress in front of a log fire, tears running down my face, crying for my sister, as my mother strokes my hair and whispers into my ear. I have cried many times for my sister – she died when we were children, and I am now 56 – but I’ve never been soothed like this before. It feels amazing.The woman touching my face and shoulders with such love is not my actual mother, who is hundreds of miles away. I am in the oak-panelled great hall of a Victorian country mansion beside the River Usk in the Brecon Beacons in Wales, and my carer is Turiya Hanover, co-founder of the Path of Love retreats. Continue reading...

One cycle means paying up to £8,000 and the birth rate is just 18%. Despite this, women are increasingly choosing this routeGrowing numbers of women are choosing to freeze their eggs because they haven’t found the right partner yet – but with the odds of conception so low, is it a waste of money?Egg freezing is a method of preserving a woman’s fertility so she can try to have children at a later date. It involves collecting her eggs, freezing them and thawing them later so they can be used in treatment. . Continue reading...

The health secretary’s call for tests to be rolled out on NHS was met with controversyThe health secretary, Matt Hancock, this week shared his shock at discovering that he is at greater than average risk for prostate cancer, despite having no family history of the disease.The revelation came after he took a predictive genetic test that assesses risk for 16 common diseases, including coronary artery disease, type 2 diabetes, asthma and breast and prostate cancers. Continue reading...

Study involving reimplanting testicular tissue later in life hailed as breakthroughTesticular tissue taken from young monkeys, which is then frozen and grafted back into their bodies later in their life, can give rise to sperm and allow them to father live young, scientists have revealed.While the approach has previously been successful in other animals, including mice, it is the first time a primate has produced offspring from the procedure. The team report the baby rhesus macaque that was born is a healthy female that has been named Grady, after “graft-derived” and “baby”. Continue reading...

Hang on, I thought. Am I about to become a prime suspect in a murder investigation?About a year ago, my parents gave me some money towards a pretty expensive metal detector. At 50, I was looking for a hobby to take me into retirement, and I’d recently got into TV shows such as The Curse Of Oak Island and Mud Men on the History channel. Both are about treasure hunting and absolutely fascinated me. I learned that mudlarking – searching shores for items during low tide – has a rich history. In the Victorian era, some of London’s poorest citizens survived on what they could find on the shores of the Thames.My workplace is close enough to the river to nip down at lunchtime, so I applied for a licence and went to try it out. Down by the water, I totally forgot that I was in the city; I could let my mind wander for an hour. There was only one problem: I was concentrating so much on hearing a bleep from my metal detector that I was forgetting to look. That is the essential part of mudlarking: concentrating on what you can see below your feet and off in the distance. I ditched the detector and went with a bucket and scraper instead. Continue reading...

Science agency says scourge of wandering trad could be slowed by fungus, which they have called its ‘natural pathogen’Australia’s national science agency will release a Brazilian leaf smut fungus to target and kill an invasive weed that covers large parts of the continent’s east coast.Researchers from the CSIRO say the scourge of wandering trad could be slowed by the introduction of the Kordyana brasiliensis fungus, which they have called its “natural pathogen”. Continue reading...

With almost half of British adults taking a daily vitamin, Graihagh Jackson and guests examine our love of supplements - including recent announcments about fortifying flour with folic acidAlmost half of adults in Britain take vitamins every day and we spend more on supplements than painkillers. This spring, the government will discuss whether to fortify flour with folic acid. The aim of the proposal is to prevent birth defects such as spina bifida by increasing folate intake in pregnant women.Graihagh Jackson looks at the history of vitamins with Dr Salim Al-Gailani from the University of Cambridge, discusses the forthcoming government debate with Linia Patel, a nutritionist and spokeswoman for the British Dietetic Association, and questions whether we really need to be popping these pills at all. Continue reading...

Could a simple blood test catch cancer before symptoms appear? Nicola Davis goes beyond the hype and investigates the future of blood diagnostics and cancerA blood test that could detect cancer earlier than current methods has long been a dream of oncologists. The hope is that these “liquid biopsies” could save countless lives by diagnosing cancer before symptoms show. They’re less invasive, quicker and easier than what is available now.However, this area of research has been plagued with hype. This happened most notably when a Silicon Valley startup – Theranos – allegedly duped investors out of hundreds of millions of pounds for the development of a blood test that would test a range of diseases, including cancer. Something that led to its founder being charged with criminal fraud. But Theranos is not the only product out there. And many others are showing real genuine promise. Continue reading...

Oil giant may lose lobby access over failure to answer climate change denial questionsExxonMobil faces losing its lobby privileges at the European parliament after the company failed to show up for the first hearing into climate change denial.ExxonMobil would become only the second multinational – after Monsanto – to lose access to MEPs, parliamentary meetings and digital resources if it loses a high-level vote expected by the end of April. Continue reading...

Beresheet spacecraft will attempt to land on the moon and measure its magnetic fieldA privately funded mission is on course to orbit the moon on 4 April. All being well, the 150kg spacecraft will then attempt to land a week later.An Israeli not-for-profit organisation, SpaceIL, owns the Beresheet craft, which was built by the space division of Israel Aerospace Industries, and launched on a SpaceX Falcon 9 rocket from Cape Canaveral, Florida, on 22 February. Continue reading...

Thousands of fossils date back to huge burst in diversity of life on Earth known as Cambrian explosionA “mindblowing” haul of fossils that captures the riot of evolution that kickstarted the diversity of life on Earth more than half a billion years ago has been discovered by researchers in China.Paleontologists found thousands of fossils in rocks on the bank of the Danshui river in Hubei province in southern China, where primitive forms of jellyfish, sponges, algae, anemones, worms and arthropods with thin whip-like feelers were entombed in an ancient underwater mudslide. Continue reading...

Lady Warnock laid foundations for special needs teaching and fertility treatment regulationsThe philosopher Mary Warnock, whose work laid the foundations for special needs education and for the regulation of fertility treatments, has died aged 94.After an early career researching ethics and philosophy and then as a headteacher, Lady Warnock was appointed in 1974 to chair a UK inquiry on special education. Her subsequent report brought about radical change by placing priority on teaching children with special educational needs within mainstream schools, and introduced the system of “statementing” children, which provides additional support. Continue reading...

The jet car scheme was given a lifeline by Ian Warhurst, who stepped in to provide finances

Wednesday night’s rare occurrence of a super worm moon coincided with the equinox. The name is a nod to the emergence of worms from the soil around the time of the March full moon Continue reading...

A rare super worm moon will loom large as it coincides with the spring equinox. It will be the third time this year a full moon has occurred near to the moon’s closest approach to Earth – making it a supermoon – and will be the last such event in 2019

Psychologists call for greater regulation of reality shows to address mental health risksPsychologists and producers who have worked in reality television have warned that the industry must do more to protect participants who are being “exploited and spat out” by the experience.After the death of the former Love Island contestant Mike Thalassitis, current and former members of production teams in the hugely popular genre said contributors often had no idea of the mental health risks attached to their sudden fame, and called for regulation to address the risks. Continue reading...

Letters from Dr Helen Drury, Christopher Ormell and Jane Lawson on ‘maths anxiety’ and Britain’s poor numeracy rateThe Nuffield Foundation’s report raises very worthy concern about the effects of “maths anxiety” and the impact that it has on children’s prospects (Report, 14 March). Without highlighting solutions, however, we run an increased risk of making maths anxiety a self-perpetuating phenomenon. The vast research base into mathematics education has shown that a cumulative and coherent maths curriculum is the solution. Teachers need to be empowered with support, materials and training to teach maths in a connected, meaningful way. Unfortunately, a lot of maths teaching in the UK is delivered in standalone episodes, leaving students without transferable foundations.

Phenomenon last occurred in spring 1905 and won’t happen again until the year 2144Those gazing up into the sky on Wednesday night are set to witness an unusual event: a super worm moon that coincides with the equinox.It will be the third time this year a full moon has occurred near to the moon’s closest approach to the Earth – making it a supermoon – and will be the last such event in 2019. Those venturing out can expect to see the moon looming larger than usual in the night sky. Continue reading...

Matt Hancock hails ‘game-changer’ but critics raise racial bias and ‘fatalism’ concernsThe health secretary is calling for predictive genetic tests for common cancers and heart disease to be rolled out on the NHS without delay.Matt Hancock, speaking at the Royal Society on Wednesday, revealed he recently took a commercial genetic test that showed he was at heightened risk of developing prostate cancer, saying he was shocked by the result. Hancock called for a national debate about the ethical issues around testing for diseases, some of which could not readily be treated. Continue reading...

A panel to promote an alternative explanation for climate change would be disastrous. Yet that’s what White House officials wantAmericans should not be fooled by the Stalinist tactics being used by the White House to try to discredit the findings of mainstream climate science.The Trump administration has already purged information about climate change from government websites, gagged federal experts and attempted to end funding for climate change programmes. Continue reading...

Research reveals striking changes in babies’ immune development that could form the basis for lifesaving vaccinesA groundbreaking study has claimed that the key to saving the lives of newborns is found in just half a teaspoon of blood.Research has revealed dramatic changes in the immune systems of newborns, which scientists say could transform our understanding of disease in babies. Continue reading...

How did the ex-CEO, now facing criminal charges, find fame and fortune? By aping the persona of a ‘tech genius’Elizabeth Holmes did not change the world, as she once promised, but she certainly captured its attention. The story of the founder of the now defunct blood-testing company Theranos is everywhere. There is a bestselling book, a popular podcast and a new documentary, The Inventor: Out for Blood in Silicon Valley, directed by the Oscar winner Alex Gibney, which premiered in the US on Monday.Why are we so obsessed with Holmes? Elementary, my dear reader: she is a mesmerisingly modern morality tale. A photogenic 19-year-old Stanford dropout starts a revolutionary blood-testing company, which police are now investigating as a possible multibillion-dollar scam. Powerful men such as Henry Kissinger give her their backing. Holmes is named the US’s youngest self-made female billionaire before the authorities come knocking and a criminal case is mounted. If you had pitched the story to Hollywood, they would have said it was far-fetched. Continue reading...

No one knows if Mary Anning had lovers. But what a new film does get right is the vital role women played in her lifeThe furore over a film portraying the 19th-century palaeontologist Mary Anning as having a female lover probably tells us more about ourselves than it does about historical accuracy onscreen. Francis Lee’s Ammonite might not be a scrupulously backed-up biopic, but it may just hit on the one thing that so many other accounts of Anning, and other early women in science, have missed: the importance of friendships and collaborations.Anning, the working-class woman whose fossil discoveries changed the world, and a modern-day icon for women in science, is once again making news. This time, however, it’s not the ancient creatures she unearthed causing the stir. Kate Winslet will play her in the new movie, and her fellow actor Saoirse Ronan has confirmed that her character, widely reported in the press as Frances Bell (a real person and friend of Anning) and Mary Anning are lovers. Cue media frenzy, with plenty of opportunity for outrage over (presumed) historical inaccuracy and claims of sexing-up an already remarkable biography, alongside salacious delight at the thought of a lesbian love affair amid the Lias. Continue reading...

Distinctive musky odour of people with Parkinson’s could lead to earlier diagnosisScientists have developed a test for Parkinson’s disease based on its signature odour after teaming up with a woman who can smell the condition before tremors and other clinical symptoms appear.The test could help doctors diagnose patients sooner and identify those in the earliest stages of the disease, who could benefit from experimental drugs that aim to protect brain cells from being killed off. Continue reading...

Kunxun was cloned from a police sniffer dog in Beijing but cost of process remains an obstacleScientists in south-west China’s Yunnan province have reportedly cloned what they called the “Sherlock Holmes of police dogs” in a programme they hope will help cut training times and costs for police dogs.The dog, named Kunxun, was cloned from a police sniffer dog by the Beijing-based Sinogene Biotechnology Company and the Yunnan Agricultural University, with support from the Ministry of Public Security, the state-owned tabloid Global Times reported. Continue reading...

Study says 30% of first-time psychotic disorders in south London linked to strong drugsFrequent cannabis use and high-strength varieties are likely to increase the chance of mental health problems among users, according to researchers behind the largest study of its kind.Experts have previously flagged a link between cannabis use and psychosis, particularly among vulnerable people with heavy use of the drug. Now research suggests the potency of the cannabis is also important, with patterns in cannabis use linked to how often new cases of psychotic disorders arise in different cities. Continue reading...

Climate must not be confused with local conditions, but remodelled broadcasts could help people understand the dangers we faceStill, and in defiance of decades worth of scientific evidence, vast numbers of people around the world refuse to accept that we are in the process of drastically altering the climate. Vast numbers more lack the information they need to interpret what is going on. This is a global problem whose importance cannot be overstated. It has no single solution. But giving up on trying to halt the damage to life on our planet is not an option. And in this context, this week’s suggestion by the former BBC weather presenter Bill Giles, that forecasts should be adapted to include information about climate change as well as local weather conditions, is extremely welcome.Weather and climate are not the same thing, and to confuse them would be unhelpful. But the rapidly developing science of weather attribution means that experts are now able to analyse extreme events including floods and heatwaves to determine the contribution of manmade climate change. Last summer’s UK heatwave, for example, was made 30 times more likely by greenhouse gases. Findings such as this could feature in the remodelled broadcasts, and play a valuable role in increasing public understanding. So could information about globally important climate-related events, such as updates on melting ice sheets in Greenland or Antarctica. Continue reading...

Karen Keskulla Uhlenbeck of the University of Texas at Austin wins one of the world’s most prestigious mathematics awardsAn American professor has become the first woman to be awarded the Abel Prize, one of the world’s most prestigious international mathematics awards.The Norwegian Academy of Science and Letters announced in Oslo on Tuesday that Karen Keskulla Uhlenbeck of the University of Texas at Austin was this year’s winner of the prize, seen by many as the Nobel Prize in mathematics. Continue reading...

On this week’s show, Claire and Sian meet up at London book fair to discuss the trends and biggest books announced for 2019 and 2020. Then they sit down with neuropsychologist AK Benjamin and novelist Anthony Good, who have written two very different books turning the tables on therapy. Benjamin’s genre-busting take on mental health, Let Me Not Be Mad, puts the author centre stage, while Good’s Kill [redacted] is a thriller in which a man grieving the murder of his wife attempts to justify his right to revenge through letters to his therapist. Continue reading...

Kate Winslet picture about renowned fossil hunter had been criticised by relatives for ‘unconfirmed’ portrait of her sexualityThe director of a new biopic about the celebrated fossil hunter Mary Anning has defended his film after criticism of its lesbian romance storyline.Ammonite, which stars Kate Winslet and Saoirse Ronan, recently began filming in Lyme Regis, the coastal town in Dorset where Anning lived in the early 19th century. Anning never married and is not known to have had any direct descendants, but a report in the Telegraph suggested her distant relatives were at odds over the film’s central relationship, a romance between Anning and Frances Bell, with whom Anning is known to have corresponded. Continue reading...

Bill Giles calls on broadcasters to add slot explaining humans’ impact on climateThe veteran weatherman Bill Giles is calling on the BBC and other major broadcasters to radically overhaul their forecasts to incorporate information about climate change.The former head of BBC weather presenters has said more needs to be done by broadcasters to highlight climate change to face the “reality more squarely and openly”. Continue reading...

Prof Joe Smith, director of the Royal Geographical Society, Prof Sir David Cannadine, president of the British Academy, and Prof Norman Gowar respond to a Guardian editorialYour editorial in defence of the humanities (13 March) is well timed and well argued. The UK needs the contribution of Stem graduates and that made by graduates with knowledge, skills and understanding gained through study of the humanities and wider social sciences. And geography, a subject that is a humanity, a social science and has part Stem designation in higher education, is well placed to make such a contribution.For example, the cabinet office’s geospatial commission estimates that UK plc can gain £11bn through the better use of the geospatial data held by organisations including the Ordnance Survey, Land Registry and the Hydrographic Office. Yet this can only be achieved if we have enough graduates trained to understand how such data can be used to benefit our communities, environments, businesses, and policy decisions – training which is provided through the study of geography. Continue reading...

Scientists say there are signs of humans having a subconscious magnetic senseIt sounds like a power to be boasted of by the X-Men, but researchers say humans might have the ability to pick up on Earth’s magnetic field.Many animals, from pigeons to turtles, use it to navigate, while research has shown cattle prefer to align themselves with the field when standing in, well, a field. Even dogs make use of it – albeit when defecating. Continue reading...

Cambridge researchers grew ‘organoid’ that spontaneously connected to spinal cordScientists have grown a miniature brain in a dish with a spinal cord and muscles attached, an advance that promises to accelerate the study of conditions such as motor neurone disease.The lentil-sized grey blob of human brain cells were seen to spontaneously send out tendril-like connections to link up with the spinal cord and muscle tissue, which was taken from a mouse. The muscles were then seen to visibly contract under the control of the so-called brain organoid. Continue reading...

Without an exit deal with the EU, the whole NI agricultural industry will be destroyed

Fireball over Kamchatka peninsula in December went largely unnoticed at the timeA meteor explosion over the Bering Sea late last year unleashed 10 times as much energy as the atomic bomb that destroyed Hiroshima, scientists have revealed.The fireball tore across the sky off Russia’s Kamchatka peninsula on 18 December and released energy equivalent to 173 kilotons of TNT. It was the largest air blast since another meteor hurtled into the atmosphere over Chelyabinsk, in Russia’s south-west, six years ago, and the second largest in the past 30 years. Continue reading...

Australian researchers believe it is the oldest viable stored semen of any species in the worldDecades after his 1960s heyday, Sir Freddie the ram has sired offspring from beyond the grave in what researchers believe is a project that shows the world’s oldest viable stored semen.A team at the University of Sydney has defrosted Sir Freddie’s 50-year-old semen and that of three other rams and successfully impregnanted it in 34 merino ewes. Continue reading...