https://www.imdb.com/title/tt14738480/

Researchers have resurrected 'zombie viruses' that laid dormant in the Siberian permafrost for up to 50,000 years, and have found that they remained infectious despite spending many millennia trapped in the frozen ground. Scientists from the French National Centre for Scientific Research revived 13 never-before-seen viruses from seven ancient permafrost samples. The oldest virus has been named Pandoravirus yedoma, which was discovered in a sample taken from the bottom of Yukechi Alas lake in Russia. It is 48,500 years old. In 2014, the same researchers unearthed a 30,000-year-old virus trapped in permafrost. The discovery was groundbreaking because, after all that time, the virus was still able to infect organisms. But now, they’ve beaten their record by reviving a virus that is 48,500 years old. Global warming: Scientists are thawing out these ancient viruses to assess their impact on public health. According to a scientific study yet to be peer-reviewed, global warming is irrevocably thawing enormous swathes of permafrost (permanently frozen) ground that covers one-quarter of the Northern Hemisphere. This has had the unsettling effect of "releasing organic materials frozen for up to a million years" - possibly deadly viruses included. "The situation would be much more disastrous in the case of a plant, animal, or human diseases caused by the revival of an ancient unknown virus," reads the study. Are viruses dangerous to humans? The authors warn that some of these “zombie viruses” could potentially be dangerous to humans. And thawing permafrost has already claimed human lives. In 2016, one child died and dozens of people were hospitalized after an anthrax outbreak in Siberia. Officials believe the outbreak started because a heat wave thawed the permafrost and unearthed a reindeer carcass infected with anthrax decades ago. About 2,300 reindeer died in the outbreak. The latest revived viruses that researchers spotted belong to the following sub-types of viruses: pandoravirus, cedratvirus, mega virus, pacmanvirus, and pithovirus. These viruses are considered “giant” because they’re large and easy to spot using light microscopy. For this reason, researchers believe many other smaller viruses have escaped scrutiny. More pandemics: One silver lining is that the study’s authors say there is a “negligible” risk of these amoeba-infecting viruses having a hazardous impact on humans. But that’s not to say that all ancient viruses are harmless. It’s unclear if these ancient viruses would be able to infect a host once exposed to outdoor conditions like heat, oxygen, and UV rays. But researchers say the chance of such a situation is increasing as more of the permafrost thaws and more people begin to occupy the melting Arctic for commercial and industrial ventures. They believe that Covid-19-style pandemics will become more common in the future as melting permafrost releases long-dormant viruses. "It is therefore legitimate to ponder the risk of ancient viral particles remaining infectious and getting back into circulation by thawing ancient permafrost layers," said the study.

#ScienceNews #Science #Spacetime #physics In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why different observers perceive differently where and when events occur. Until the 20th century, it was assumed that the three-dimensional geometry of the universe (its spatial expression in terms of coordinates, distances, and directions) was independent of one-dimensional time. The physicist Albert Einstein helped develop the idea of spacetime as part of his theory of relativity. Prior to his pioneering work, scientists had two separate theories to explain physical phenomena: Isaac Newton's laws of physics described the motion of massive objects, while James Clerk Maxwell's electromagnetic models explained the properties of light. However, in 1905, Einstein based a work on special relativity on two postulates: 1. The laws of physics are invariant (i.e., identical) in all inertial systems (i.e., non-accelerating frames of reference) 2. The speed of light in a vacuum is the same for all inertial observers, regardless of the motion of the light source. The logical consequence of taking these postulates together is the inseparable joining of the four dimensions—hitherto assumed as independent—of space and time. Many counterintuitive consequences emerge: in addition to being independent of the motion of the light source, the speed of light is constant regardless of the frame of reference in which it is measured; the distances and even temporal ordering of pairs of events change when measured in different inertial frames of reference (this is the relativity of simultaneity); and the linear additivity of velocities no longer holds true. Einstein framed his theory in terms of kinematics (the study of moving bodies). His theory was an advance over Lorentz's 1904 theory of electromagnetic phenomena and Poincaré's electrodynamic theory. Although these theories included equations identical to those that Einstein introduced (i.e., the Lorentz transformation), they were essentially ad hoc models proposed to explain the results of various experiments—including the famous Michelson–Morley interferometer experiment—that were extremely difficult to fit into existing paradigms. In 1908, Hermann Minkowski—once one of the math professors of a young Einstein in Zürich—presented a geometric interpretation of special relativity that fused time and the three spatial dimensions of space into a single four-dimensional continuum now known as Minkowski space. A key feature of this interpretation is the formal definition of the spacetime interval. Although measurements of distance and time between events differ for measurements made in different reference frames, the spacetime interval is independent of the inertial frame of reference in which they are recorded. Minkowski's geometric interpretation of relativity was to prove vital to Einstein's development of his 1915 general theory of relativity, wherein he showed how mass and energy curve flat spacetime into a pseudo-Riemannian manifold.

#ScienceNews #Science #dinosaurs Mammals survived the asteroid that wiped out the dinosaurs by evolutionarily hedging their bets, generating an array of varied species that set them up to weather the prehistoric apocalypse, according to a new analysis. By looking at how ecosystems in prehistoric North America changed – or stayed the same – Jorge García-Girón at the University of León, Spain, and his colleagues hoped to gain some insight into why mammals and other small creatures thrived after the impact while birds were all that remained of the dinosaurs. “I do not believe that selectivity favouring small-bodied animals alone can explain the difference between survival and extinction between mammals and dinosaurs,” says García-Girón. The real picture is much more complex and has to do with the spread of different diets, behaviours and niches that animals had before the impact, he says. Drawing on more than 1600 fossils of various North American dinosaurs, fish, amphibians, reptiles, birds and mammals, the team created an estimation of the niches each extinct species occupied. For each species, the researchers assigned a body size, habitat and diet, plugging this information into a computational model developed by ecologists to track how food webs shift over time. The team found that dinosaurs present in North America 66 million years ago more or less resembled those of 18 million years earlier and represented a form of ecological stability. Mammals, meanwhile, persistently pushed the envelope of adaptation, evolving into a vast array of climbing, gliding, swimming, burrowing and other forms during this period. Contrary to some previous studies that proposed a decline in the number of dinosaur species approaching the impact, the researchers found no such dip. If anything, dinosaurs like T. rex and Triceratops were filling the same roles their ancestors did millions of years earlier. Mammals, on the other hand, were more flexible. “It not only amazed me how mammals managed to thrive in the highly complex, and probably dangerous, dinosaur-dominated ecosystems,” says García-Girón, but how also how rapidly our ancestors moved into vacant niches after the asteroid hit. “Dinosaurs going extinct is certainly a captivating story, but they were just one of the many taxa that were dramatically affected by the… mass extinction,” says Lucas Weaver at the University of Michigan. The study brings together the data various researchers have collected into a new theoretical model that can continue to be assessed with new discoveries, says Weaver, and such ecosystem-wide approaches are likely to provide the next big insights into what happened before and after this cataclysmic event. Journal reference: Science Advances, DOI: 10.1126/sciadv.add5040

https://www.nature.com/articles/d41586-018-05095-z

https://www.lyricsondemand.com/miscellaneouslyrics/fightsongslyrics/auburnufightsonglyrics.html

https://www.sciencedaily.com/releases/2022/11/221130114712.htm

#ScienceNews #Science #carnivore #evolution #Smilodon #sabre-toothed A team of researchers led by Narimane Chatar, a doctoral student at the EDDyLab of the University of Liège (Belgium), has tested the biting efficiency of Smilodon, an extinct species of carnivore close to the extant felines. Using high-precision 3D scans and simulation methods, the team has just revealed how these animals managed to bite despite the impressive length of their teeth. Ancient carnivorous mammals developed a wide range of skull and tooth shapes throughout their evolution. However, few of these evolutions have yet matched those of the iconic sabre-toothed felid Smilodon. Other groups of mammals, such as the now extinct nimravids, have also evolved a similar morphology, with species having sabre teeth but also much shorter canines, similar to those of the lions, tigers, caracals, domestic cats, etc. that we know today. This phenomenon of similar morphologies appearing in different groups of organisms is known as convergent evolution; felids and nimravids being an amazing example of convergence. As there are no modern equivalents of animals with such sabre-shaped teeth, the hunting method of Smilodon and similar species has remained obscure and hotly debated. It was first suggested that all sabre-toothed species hunted in the same way, regardless of the length of their canines, a hypothesis that is now controversial. So the question remained ... how did this variety of 'sabre-toothed cat' hunt? The enormous canines of the extinct sabre-toothed cat Smilodon imply that this animal had to open its jaw extremely wide, 110° according to some authors, in order to use them effectively," explains Prof. Valentin Fischer, director of the EDDyLab at ULiège. However, the mechanical feasibility and efficiency of Smilodon and its relatives to bite at such a large angle is unknown, leaving a gap in our understanding of this very fundamental question about sabre-toothed predators." Using high-precision 3D scanners and analytical methods derived from engineering, an international team of Belgian and North American scientists has just revealed how these animals probably used their impressive weapons. Narimane Chatar, a PhD student at the EDDyLab of the University of Liege and lead author of the study, collected a large amount of three-dimensional data. She first scanned and modelled the skulls, mandibles and muscles of numerous extinct and extant species of felids and nimravids. "Each species was analysed in several scenarios: a bite was simulated on each tooth at three different biting angles: 30°, as commonly seen in extant felids, but also larger angles (60° and 90°). In total, we carried out 1,074 bite simulations to cover all the possibilities," explains Narimane Chatar. To do this, the young researcher used the finite element method. This is an exciting application of the finite element approach, which allows palaeontologists to modify and computationally simulate different bite angles and to subject skull models to virtual stresses without damaging the precious fossil specimens," says Prof. Jack Tseng, Professor and Curator of Palaeontology at the University of California, Berkeley, and co-author of the study. Our comprehensive analyses provide the most detailed insight to date into the diversity and nuances of sabre tooth bite mechanics." One of the results obtained by the team is the understanding of the distribution of stress (pressure) on the mandible during biting. This stress shows a continuum across the animals analysed, with the highest values measured in species with the shortest upper canines and the lowest stress values measured in the most extreme sabre-toothed species. The researchers also noted that stress decreased with increasing bite angle, but only in sabre-toothed species. However, the way in which these animals transmitted force to the bite point and the deformation of the mandible resulting from the bite were remarkably similar across the dataset, indicating comparable effectiveness regardless of canine length. "The results show both the possibilities and the limits of evolution; animals facing similar problems in their respective ecosystems often end up looking alike through convergent evolution. However, Narimane Chatar's results also show that there can be several ways to be an effective killer, whether you are sabre-toothed or not," concludes Valentin Fischer. This phenomenon, called 'many-to-one' systems, means that distinct morphologies can result in a similar function, such as the fact that bears and cats are both efficient fishers. This multiplicity of morphologies indicates that there is no single optimal form of sabre-toothed predator.

https://physicsworld.com/a/when-physics-meets-high-performance-computing/

https://physicsworld.com/a/self-powered-smart-watches-for-cows-how-honey-bees-cope-with-topological-defects/