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Categories: Ecology: Nature, Physics: General

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Researchers have developed a new class of integrated photonic devices -- 'leaky-wave metasurfaces' -- that convert light initially confined in an optical waveguide to an arbitrary optical pattern in free space. These are the first to demonstrate simultaneous control of all four optical degrees of freedom. Because they're so thin, transparent, and compatible with photonic integrated circuits, they can be used to improve optical displays, LIDAR, optical communications, and quantum optics.

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Quantum dots in semiconductors such as silicon or gallium arsenide have long been considered hot candidates for hosting quantum bits in future quantum processors. Scientists have now shown that bilayer graphene has even more to offer here than other materials. The double quantum dots they have created are characterized by a nearly perfect electron-hole-symmetry that allows a robust read-out mechanism -- one of the necessary criteria for quantum computing.

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Photovoltaics, the conversion of light to electricity, is a key technology for sustainable energy. Since the days of Max Planck and Albert Einstein, we know that light as well as electricity are quantized, meaning they come in tiny packets called photons and electrons. In a solar cell, the energy of a single photon is transferred to a single electron of the material, but no more than one. Only a few molecular materials like pentacene are an exception, where one photon is converted to two electrons instead. This excitation doubling, which is called exciton fission, could be extremely useful for high-efficiency photovoltaics, specifically to upgrade the dominant technology based on silicon. Researchers have now deciphered the first step of this process by recording an ultrafast movie of the photon-to-electricity conversion process, resolving a decades-old debate about the mechanism of the process.

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Using a long-term multifactor experimental field site researchers showed that experimental warming of a tallgrass prairie ecosystem significantly altered the community structure of soil archaea and reduced their taxonomic and phylogenetic diversity.

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Researchers have demonstrated a prototype lidar system that uses quantum detection technology to acquire 3D images while submerged underwater. The high sensitivity of this system could allow it to capture detailed information even in extremely low-light conditions found underwater.

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An international team of researchers has developed a comprehensive manual for engineering spin dynamics in nanomagnets -- an important step toward advancing spintronic and quantum-information technologies.

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For decades, scientists have used the amount of seaweed at the ocean's surface as a proxy for the health of coral reefs below. However, a new global study of more than 1,200 marine locations over a 16-year period reveals that this approach has been misleading -- and may even have hidden signs of reef stress.

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With glaciers melting at unprecedented rates due to climate change, invertebrates that live in the cold meltwater rivers of the European Alps will face widespread habitat loss, warn researchers. Many of the species are likely to become restricted to cold habitats that will only persist higher in the mountains, and these areas are also likely to see pressures from the skiing and tourism industries or from the development of hydroelectric plants.

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Large numbers can only be factorized with a great deal of computational effort. Physicists are now providing a blueprint for a new type of quantum computer to solve the factorization problem, which is a cornerstone of modern cryptography.

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A new study has found links at the atomic level between photosynthesis and exciton condensates -- a strange state of physics that allows energy to flow frictionlessly through a material. The finding is scientifically intriguing and may suggest new ways to think about designing electronics, the authors said.

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In the face of global warming and other environmental changes, corals in the Atlantic Ocean have declined precipitously in recent years, while corals in the Pacific and Indian Oceans are faring better. By describing several species of symbiotic algae that these corals need to grow, an international team has found that these mutualistic relationships from the Indo-Pacific may be more flexible and ultimately resilient to higher ocean temperatures than those in the Atlantic.

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According to researchers, a new analysis of an 80-million-year-old permineralized pollen cone found in the Campanian Holz Shale formation located in Silverado Canyon, California, offers a more accurate cycad natural history -- one where the plants diversified during the Cretaceous.

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Like animals, many plant species are struggling to adapt to a human-dominated planet. However, plants are often overlooked in conservation efforts, even though they are cheaper and easier to protect than animals and play a pivotal role in bolstering our food, fuel, and medical systems. A plant ecologist suggests an approach for preventing all future land plant extinctions across the globe which includes training more plant experts, building an online 'metaherbarium,' and creating 'microreserves.'

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Using a "spooky" phenomenon of quantum physics, researchers have discovered a way to double the resolution of light microscopes.

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Whenever SLAC National Accelerator Laboratory's linear accelerator is on, packs of around a billion electrons each travel together at nearly the speed of light through metal piping. These electron bunches form the accelerator's particle beam, which is used to study the atomic behavior of molecules, novel materials and many other subjects. But trying to estimate what a particle beam actually looks like as it travels through an accelerator is difficult, leaving scientists often with only a rough approximation of how a beam will behave during an experiment. Now, researchers have developed an algorithm that more precisely predicts a beam's distribution of particle positions and velocities as it zips through an accelerator.

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A machine-learning approach can give scientists insight into the environmental preferences of microbes, based only on their genes. The approach has practical research implications: it could help researchers more efficiently grow bacteria in the laboratory. It could also lead to smarter use of microbes in agriculture, ecological restoration, and even probiotics.

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Scientists from around the globe are using the largest mammalian genomic dataset in history to determine the evolutionary history of the human genome in the context of mammalian evolutionary history. Their ultimate goal is to better identify the genetic basis for traits and diseases in people and other species.

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New research pushes back the oldest evidence of C4 grass-dominated habitats in Africa -- and globally -- by more than 10 million years, with important implications for primate evolution and the origins of tropical C4 grasslands and savanna ecosystems across the African continent and around the world.

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Researchers are investigating the causes and consequences of the worldwide insect decline as well as considering potential countermeasures.

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Each year approximately 10 million waterfowl fly north to their breeding grounds in the Prairie Pothole Region of North America, but the landscape that greets them has changed. Weather patterns and agricultural practices have significantly transformed the pothole-dotted native grasslands that waterfowl have used for thousands of years.