Liverpool John Moores University

In a remarkable discovery, astronomers have found a disc around a young star in the Large Magellanic Cloud, a galaxy neighboring ours. It's the first time such a disc, identical to those forming planets in our own Milky Way, has ever been found outside our galaxy. The new observations reveal a massive young star, growing and accreting matter from its surroundings and forming a rotating disc. In a remarkable discovery, astronomers have found a disc around a young star in the Large Magellanic Cloud, a galaxy neighbouring ours. It's the first time such a disc, identical to those forming planets in our own Milky Way, has ever been found outside our galaxy. The new observations reveal a massive young star, growing and accreting matter from its surroundings and forming a rotating disc. The detection was made using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, in which the European Southern Observatory (ESO) is a partner. "When I first saw evidence for a rotating structure in the ALMA data I could not believe that we had detected the first extragalactic accretion disc, it was a special moment," says Anna McLeod, an associate professor at Durham University in the UK and lead author of the study published today in Nature. "We know discs are vital to forming stars and planets in our galaxy, and here, for the first time, we're seeing direct evidence for this in another galaxy." This study follows up observations with the Multi Unit Spectroscopic Explorer (MUSE) instrument on ESO's Very Large Telescope (VLT), which spotted a jet from a forming star -- the system was named HH 1177 -- deep inside a gas cloud in the Large Magellanic Cloud. "We discovered a jet being launched from this young massive star, and its presence is a signpost for ongoing disc accretion," McLeod says. But to confirm that such a disc was indeed present, the team needed to measure the movement of the dense gas around the star. As matter is pulled towards a growing star, it cannot fall directly onto it; instead, it flattens into a spinning disc around the star. Closer to the centre, the disc rotates faster, and this difference in speed is the smoking gun that shows astronomers an accretion disc is present. "The frequency of light changes depending on how fast the gas emitting the light is moving towards or away from us," explains Jonathan Henshaw, a research fellow at Liverpool John Moores University in the UK, and co-author of the study. "This is precisely the same phenomenon that occurs when the pitch of an ambulance siren changes as it passes you and the frequency of the sound goes from higher to lower." The detailed frequency measurements from ALMA allowed the authors to distinguish the characteristic spin of a disc, confirming the detection of the first disc around an extragalactic young star. Massive stars, like the one observed here, form much more quickly and live far shorter lives than low-mass stars like our Sun. In our galaxy, these massive stars are notoriously challenging to observe and are often obscured from view by the dusty material from which they form at the time a disc is shaping around them. However, in the Large Magellanic Cloud, a galaxy 160 000 light-years away, the material from which new stars are being born is fundamentally different from that in the Milky Way. Thanks to the lower dust content, HH 1177 is no longer cloaked in its natal cocoon, offering astronomers an unobstructed, if far away, view of star and planet formation.

It could be the shopping trip that saves your life: supermarket trolleys are helping to diagnose atrial fibrillation which can then be treated to prevent disabling or fatal strokes. It could be the shopping trip that saves your life: supermarket trolleys are helping to diagnose atrial fibrillation which can then be treated to prevent disabling or fatal strokes. The research is presented today at ACNAP 2023, a scientific congress of the European Society of Cardiology (ESC).1 "This study shows the potential of taking health checks to the masses without disrupting daily routines," said study author Professor Ian Jones of Liverpool John Moores University, UK. "Over the course of two months, we identified 39 patients who were unaware that they had atrial fibrillation. That's 39 people at greater risk of stroke who received a cardiologist appointment." More than 40 million people around the world have atrial fibrillation, the most common heart rhythm disorder.2 Atrial fibrillation increases the risk of stroke by five-fold. These strokes are often fatal or disabling. Anticoagulation substantially lowers risk, but many people only discover they have atrial fibrillation after they have a stroke.3 Screening programmes are therefore needed to identify people with the condition so they can receive preventive medication. The SHOPS-AF study investigated whether embedding electrocardiogram (ECG) sensors into the handles of supermarket trolleys could effectively identify shoppers with atrial fibrillation (see photo).4,5 Ten trolleys had a sensor placed in the handle and were used across four supermarkets with pharmacies in Liverpool during the two month study. Shoppers were asked to use a modified trolley and hold the handlebar for at least 60 seconds. If the sensor did not detect an irregular heartbeat, it lit up green. These participants had a manual pulse check by a researcher to confirm there was no atrial fibrillation. If an irregular heartbeat was found, the sensor lit up red. The in-store pharmacist then did a manual pulse check and another sensor reading using a standalone bar not attached to a trolley with the participant standing still. The study cardiologist reviewed the ECG recordings of participants with a red light and/or irregular pulse. Participants were informed of the results, which were: 1) no atrial fibrillation; 2) unclear ECG and an invitation to repeat the measurement; or 3) atrial fibrillation confirmed and a cardiologist appointment within two weeks. A total of 2,155 adults used a shopping trolley. ECG data were available for 220 participants who either had a red light on the sensor and/or an irregular pulse, suggesting atrial fibrillation. After ECG review by the study cardiologist, there was no evidence of atrial fibrillation in 115 participants, 46 recordings were unclear, and atrial fibrillation was diagnosed in 59 participants. The average age of the 59 participants with atrial fibrillation was 74 years and 43% were women. Of those, 20 already knew they had atrial fibrillation and 39 were previously undiagnosed. To assess the accuracy of screening using this method, the researchers conducted three analyses: 1) excluding all 46 unclear ECGs; 2) assuming all unclear ECGs were atrial fibrillation; and 3) assuming all unclear ECGs were not atrial fibrillation. This showed that the sensor's sensitivity ranged from 0.70 to 0.93 and specificity ranged from 0.15 to 0.97. This resulted in a positive predictive value of 0.24 to 0.56, meaning that only one-quarter to one-half of those found to have atrial fibrillation according to the sensor and/or manual pulse check actually had the condition (i.e. there were a high number of false positives). The negative predictive value was 0.55 to 1.00, meaning that around half of actual atrial fibrillation cases would be missed using this method (i.e. false negatives). Professor Jones said: "Nearly two-thirds of the shoppers we approached were happy to use a trolley, and the vast majority of those who declined were in a rush rather than wary of being monitored. This shows that the concept is acceptable to most people and worth testing in a larger study. Before we conduct SHOPS-AF II, some adjustments are needed to make the system more accurate. For example, having a designated position on the bar to hold onto, as hand movement interfered with the readings. In addition, ESC Guidelines require just a 30 second ECG to diagnose atrial fibrillation,2 so we aim to find a sensor that will halve the time shoppers need to continuously hold the bar." He concluded: "Checking for atrial fibrillation while people do their regular shopping holds promise for preventing strokes and saving lives. A crucial aspect is providing immediate access to a health professional who can explain the findings and refer patients on for confirmatory tests and medication if needed."

Along the shores of Africa's Lake Victoria in Kenya roughly 2.9 million years ago, early human ancestors used some of the oldest stone tools ever found to butcher hippos and pound plant material, according to new research. The study presents what are likely to be the oldest examples of a hugely important stone-age innovation known to scientists as the Oldowan toolkit, as well as the oldest evidence of hominins consuming very large animals. Excavations at the site, named Nyayanga and located on the Homa Peninsula in western Kenya, also produced a pair of massive molars belonging to the human species' close evolutionary relative Paranthropus. The teeth are the oldest fossilized Paranthropus remains yet found, and their presence at a site loaded with stone tools raises intriguing questions about which human ancestor made those tools. Along the shores of Africa's Lake Victoria in Kenya roughly 2.9 million years ago, early human ancestors used some of the oldest stone tools ever found to butcher hippos and pound plant material, according to new research led by scientists with the Smithsonian's National Museum of Natural History and Queens College, CUNY, as well as the National Museums of Kenya, Liverpool John Moores University and the Cleveland Museum of Natural History. The study, published today, Feb. 9, in the journal Science, presents what are likely to be the oldest examples of a hugely important stone-age innovation known to scientists as the Oldowan toolkit, as well as the oldest evidence of hominins consuming very large animals. Though multiple lines of evidence suggest the artifacts are likely to be about 2.9 million years old, the artifacts can be more conservatively dated to between 2.6 and 3 million years old, said lead study author Thomas Plummer of Queens College, research associate in the scientific team of the Smithsonian's Human Origins Program. Excavations at the site, named Nyayanga and located on the Homa Peninsula in western Kenya, also produced a pair of massive molars belonging to the human species' close evolutionary relative Paranthropus. The teeth are the oldest fossilized Paranthropus remains yet found, and their presence at a site loaded with stone tools raises intriguing questions about which human ancestor made those tools, said Rick Potts, senior author of the study and the National Museum of Natural History's Peter Buck Chair of Human Origins. "The assumption among researchers has long been that only the genus Homo, to which humans belong, was capable of making stone tools," Potts said. "But finding Paranthropus alongside these stone tools opens up a fascinating whodunnit." Whichever hominin lineage was responsible for the tools, they were found more than 800 miles from the previously known oldest examples of Oldowan stone tools -- 2.6-million-year-old tools unearthed in Ledi-Geraru, Ethiopia. This greatly expands the area associated with Oldowan technology's earliest origins. Further, the stone tools from the site in Ethiopia could not be tied to any particular function or use, leading to speculation about what the Oldowan toolkit's earliest uses might have been. Through analysis of the wear patterns on the stone tools and animal bones discovered at Nyayanga, Kenya, the team behind this latest discovery shows that these stone tools were used by early human ancestors to process a wide range of materials and foods, including plants, meat and even bone marrow. The Oldowan toolkit includes three types of stone tools: hammerstones, cores and flakes. Hammerstones can be used for hitting other rocks to create tools or for pounding other materials. Cores typically have an angular or oval shape, and when struck at an angle with a hammerstone, the core splits off a piece, or flake, that can be used as a cutting or scraping edge or further refined using a hammerstone. "With these tools you can crush better than an elephant's molar can and cut better than a lion's canine can," Potts said. "Oldowan technology was like suddenly evolving a brand-new set of teeth outside your body, and it opened up a new variety of foods on the African savannah to our ancestors." Potts and Plummer were first drawn to the Homa Peninsula in Kenya by reports of large numbers of fossilized baboon-like monkeys named Theropithecus oswaldi, which are often found alongside evidence of human ancestors. After many visits to the peninsula, a local man named Peter Onyango working with the team suggested they check out fossils and stone tools eroding from a nearby site that was ultimately named Nyayanga after an adjacent beach. Beginning in 2015, a series of excavations at Nyayanga returned a trove of 330 artifacts, 1,776 animal bones and the two hominin molars identified as belonging to Paranthropus. The artifacts, Plummer said, were clearly part of the stone-age technological breakthrough that was the Oldowan toolkit. Compared to the only other stone tools known to have preceded them -- a set of 3.3-million-year-old artifacts unearthed at a site called Lomekwi 3, just west of Lake Turkana in Kenya -- Oldowan tools were a significant upgrade in sophistication. Oldowan tools were systematically produced and often fashioned using what is known as "freehand percussion," meaning the core was held in one hand and then struck with a hammerstone being wielded by the opposing hand at just the right angle to produce a flake -- a technique that requires significant dexterity and skill. By contrast, most of the artifacts from Lomekwi 3 were created by using large stationary rocks as anvils, with the toolmaker either banging a core against the flat anvil stone to create flakes or by setting the core down on the anvil and striking it with a hammerstone. These more rudimentary modes of fabrication resulted in larger, cruder and more haphazard-looking tools. Over time, the Oldowan toolkit spread all the way across Africa and even as far as modern-day Georgia and China, and it was not meaningfully replaced or amended until some 1.7 million years ago when the hand-axes of the Acheulean first appeared. As part of their study, the researchers conducted microscopic analysis of wear patterns on the stone tools to determine how they were used, and they examined any bones seen to exhibit potential cut marks or other kinds of damage that might have come from stone tools. The site featured at least three individual hippos. Two of these incomplete skeletons included bones that showed signs of butchery. The team found a deep cut mark on one hippo's rib fragment and a series of four short, parallel cuts on the shin bone of another. Plummer said they also found antelope bones that showed evidence of hominins slicing away flesh with stone flakes or of having been crushed by hammerstones to extract marrow. The analysis of wear patterns on 30 of the stone tools found at the site showed that they had been used to cut, scrape and pound both animals and plants. Because fire would not be harnessed by hominins for another 2 million years or so, these stone toolmakers would have eaten everything raw, perhaps pounding the meat into something like a hippo tartare to make it easier to chew. Using a combination of dating techniques, including the rate of decay of radioactive elements, reversals of Earth's magnetic field and the presence of certain fossil animals whose timing in the fossil record is well established, the research team was able to date the items recovered from Nyayanga to between 2.58 and 3 million years old. "This is one of the oldest if not the oldest example of Oldowan technology," Plummer said. "This shows the toolkit was more widely distributed at an earlier date than people realized, and that it was used to process a wide variety of plant and animal tissues. We don't know for sure what the adaptive significance was but the variety of uses suggests it was important to these hominins." The discovery of teeth from the muscular-jawed Paranthropus alongside these stone tools begs the question of whether it might have been that lineage rather than the Homo genus that was the architect of the earliest Oldowan stone tools, or perhaps even that multiple lineages were making these tools at roughly the same time. The excavations behind this study offer a snapshot of the world humans' ancestors inhabited and help illustrate the ways that stone technology allowed these early hominins to adapt to different environments and, ultimately, give rise to the human species. "East Africa wasn't a stable cradle for our species' ancestors," Potts said. "It was more of a boiling cauldron of environmental change, with downpours and droughts and a diverse, ever-changing menu of foods. Oldowan stone tools could have cut and pounded through it all and helped early toolmakers adapt to new places and new opportunities, whether it's a dead hippo or a starchy root." This research was supported by funding from the Smithsonian, the Leakey Foundation, the National Science Foundation, the Wenner-Gren Foundation, the City University of New York, the Donner Foundation and the Peter Buck Fund for Human Origins Research.