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Categories: Paleontology: General, Physics: Acoustics and Ultrasound

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The Greenland ice sheet lies thousands of miles from North America yet holds clues to the distant continent's environmental history. Nearly two miles thick in places, the ice sheet grows as snow drifts from the sky and builds up over time. But snow isn't the only thing carried in by air currents that swirl around the atmosphere, with microscopic pollen grains and pieces of ash mixing with snowfall and preserving records of the past in the ice. A new study examined these pollen grains and identified how eastern Canada's forests grew, retreated, and changed through time.

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Inspired during field work in South Australia's Flinders Ranges, geoscientists have proposed that all-time low volcanic carbon dioxide emissions triggered a 57-million-year-long global 'Sturtian' ice age.

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Dinosaurs' range of locomotion made them incredibly adaptable, researchers have found.

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The rivers of Australia, which once flowed across its now dry interior, used to host a range of bizarre animals -- including a sleek predatory lobe-finned fish with large fangs and bony scales. The newly described fossil fish discovered in remote fossil fields west of Alice Springs has been named Harajicadectes zhumini by palaeontologists.

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Scientists have found soundwaves from low-intensity focused ultrasound aimed at a place deep in the brain called the insula can reduce both the perception of pain and other effects of pain, such as heart rate changes.

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In the fossil record, trees typically are preserved with only their trunks. They don't usually include any leaves to show what their canopies and overall forms may have looked like. In a new study, researchers describe fossilized trees from New Brunswick, Canada with a surprising and unique three-dimensional crown shape.

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Researchers demonstrated a 300 GHz-band wireless link that was able to transmit data over a single channel at a rate of 240 gigabits per second. The wireless communication system employs signal generators based on lasers that have ultra-low phase noise in the sub-terahertz band. This rate is the highest so far reported at these frequencies and is a substantial step forward in 300 GHz-band communications for 6G networks.

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Evolutionary biologists report they have combined PET scans of modern pigeons along with studies of dinosaur fossils to help answer an enduring question in biology: How did the brains of birds evolve to enable them to fly?

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A new study, which centers on evidence from skulls of a 6-million-year-old fossil ape, Lufengpithecus, offers important clues about the origins of bipedal locomotion courtesy of a novel method: analyzing its bony inner ear region using three-dimensional CT-scanning. The inner ear appears to provide a unique record of the evolutionary history of ape locomotion.

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Researchers are developing a new type of sensor that reacts to certain sound waves, causing it to vibrate. The sensor is a metamaterial that acquires its special properties through the structuring of the material. Passive sound-sensitive sensors could be used to monitor buildings, earthquakes or certain medical devices and save millions of batteries.

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Instead of tubular commercial aircraft, other designs could be used in the future: Jets with a blended wing body would fly more efficiently and make less noise -- but how would the noise emissions from these new types of aircraft affect people?

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DNA from ancient feces can offer archaeologists new clues about the life and health of Japanese people who lived thousands of years ago, according to a new study.

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The brown bear is one of the largest living terrestrial carnivores, and is widely distributed across the Northern Hemisphere. Unlike many other large carnivores that went extinct at the end of the last Ice Age (cave bear, sabretoothed cats, cave hyena), the brown bear is one of the lucky survivors that made it through to the present. The question has puzzled biologists for close to a century -- how was this so?

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Owls produce negligible noise while flying. While many studies have linked the micro-fringes in owl wings to their silent flight, the exact mechanisms have been unclear. Now, a team of researchers has uncovered the effects of these micro-fringes on the sound and aerodynamic performance of owl wings through computational fluid dynamic simulations. Their findings can inspire biomimetic designs for the development of low-noise fluid machinery.

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Gliding winged-reptiles were amongst the ancient crocodile residents of the Mendip Hills in Somerset, England, researchers at the have revealed.

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Scientists have revealed that low-frequency ultrasound influences blood parameters. The findings suggest that ultrasound's effect on haemoglobin can improve oxygen's transfer from the lungs to bodily tissues. The research was undertaken on 300 blood samples collected from 42 pulmonary patients.

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A new study shows the Megalodon, a gigantic shark that went extinct 3.6 million years ago, was more slender than earlier studies suggested. This finding changes scientists' understanding of Megalodon behavior, ancient ocean life, and why the sharks went extinct.

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An international team of researchers has uncovered a remarkable genetic phenomenon in lycophytes, which are similar to ferns and among the oldest land plants. Their study reveals that these plants have maintained a consistent genetic structure for over 350 million years, a significant deviation from the norm in plant genetics.

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A team of scientists has succeeded in cooling traveling sound waves in wave-guides considerably further than has previously been possible using laser light. This achievement represents a significant move towards the ultimate goal of reaching the quantum ground state of sound in wave-guides. Unwanted noise generated by the acoustic waves at room temperature can be eliminated. This experimental approach both provides a deeper understanding of the transition from classical to quantum phenomena of sound and is relevant to quantum communication systems and future quantum technologies.

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The new theoretical research proposes that animal size over time depends on two key ecological factors.