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    High altitudes may be a climate refuge for some birds, but not these hummingbirds

    Cooler, higher locales may not be very welcoming to some hummingbirds trying to escape rising temperatures and other effects of climate change.

    Anna’s hummingbirds live no higher than about 2,600 meters above sea level. If the birds attempt to expand their range to include higher altitudes, they may struggle to fly well in the thinner air, researchers report May 26 in the Journal of Experimental Biology.

    These hummingbirds have expanded their range in the past. Once only found in Southern California, the birds now live as far north as Vancouver, says Austin Spence, an ecologist at the University of California, Davis. That expansion is probably due to climate change and people using feeders to attract hummingbirds, he says.

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    Spence and colleagues collected 26 Anna’s hummingbirds (Calypte anna) from different elevations in the birds’ natural range in California. The team transported the birds to an aviary about 1,200 meters above sea level and measured their metabolic rate when hovering. After relocating the hummingbirds to a field station at 3,800 meters altitude, the researchers let the birds rest for at least 12 hours and then measured that rate again.

    The rate was 37 percent lower, on average, at the higher elevation than the aviary, even though the birds should have been working harder to stay aloft in the thinner air (SN: 2/8/18). At higher altitudes, hovering, which takes a lot of energy compared with other forms of flight, is more challenging and requires even more energy, Spence says. The decrease in metabolic rate shows that the birds’ hovering performance was suffering, he says. “Low oxygen and low air pressure may be holding them back as they try to move upslope.”

    Additional work is needed to see whether the birds might be able to better adjust if given weeks or months to acclimate to the conditions at gradually higher altitudes. More

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    Agriculture tech use opens possibility of digital havoc

    Wide-ranging use of smart technologies is raising global agricultural production but international researchers warn this digital-age phenomenon could reap a crop of another kind — cybersecurity attacks.
    Complex IT and math modelling at King Abdulaziz University in Saudi Arabia, Aix-Marseille University, France and Flinders University in South Australia, has highlighted the risks in a new article in the open access journal Sensors.
    “Smart sensors and systems are used to monitor crops, plants, the environment, water, soil moisture, and diseases,” says lead author Professor Abel Alahmadi from King Abdulaziz University.
    “The transformation to digital agriculture would improve the quality and quantity of food for the ever-increasing human population, which is forecast to reach 10.9 billion by 2100.”
    This progress in production, genetic modification for drought-resistant crops, and other technologies is prone to cyber-attack — particularly if the ag-tech sector doesn’t take adequate precautions like other corporate or defence sectors, researchers warn.
    Flinders University researcher Dr Saeed Rehman says the rise of internet connectivity and smart low-power devices has facilitated the shift of many labour-intensive food production jobs into the digital domain — including modern techniques for accurate irrigation, soil and crop monitoring using drone surveillance.
    “However, we should not overlook security threats and vulnerabilities to digital agriculture, in particular possible side-channel attacks specific to ag-tech applications,” says Dr Rehman, an expert in cybersecurity and networking.
    “Digital agriculture is not immune to cyber-attack, as seen by interference to a US watering system, a meatpacking firm, wool broker software and an Australian beverage company.”
    “Extraction of cryptographic or sensitive information from the operation of physical hardware is termed side-channel attack,” adds Flinders co-author Professor David Glynn.
    “These attacks could be easily carried out with physical access to devices, which the cybersecurity community has not explicitly investigated.”
    The researchers recommend investment into precautions and awareness about the vulnerabilities of digital agriculture to cyber-attack, with an eye on the potential serious effects on the general population in terms of food supply, labour and flow-on costs.
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    Materials provided by Flinders University. Note: Content may be edited for style and length. More

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    Tiny robotic crab is smallest-ever remote-controlled walking robot

    Northwestern University engineers have developed the smallest-ever remote-controlled walking robot — and it comes in the form of a tiny, adorable peekytoe crab.
    Just a half-millimeter wide, the tiny crabs can bend, twist, crawl, walk, turn and even jump. The researchers also developed millimeter-sized robots resembling inchworms, crickets and beetles. Although the research is exploratory at this point, the researchers believe their technology might bring the field closer to realizing micro-sized robots that can perform practical tasks inside tightly confined spaces.
    The research will be published on Wednesday (May 25) in the journal Science Robotics. Last September, the same team introduced a winged microchip that was the smallest-ever human-made flying structure.
    “Robotics is an exciting field of research, and the development of microscale robots is a fun topic for academic exploration,” said John A. Rogers, who led the experimental work. “You might imagine micro-robots as agents to repair or assemble small structures or machines in industry or as surgical assistants to clear clogged arteries, to stop internal bleeding or to eliminate cancerous tumors — all in minimally invasive procedures.”
    “Our technology enables a variety of controlled motion modalities and can walk with an average speed of half its body length per second,” added Yonggang Huang, who led the theoretical work. “This is very challenging to achieve at such small scales for terrestrial robots.”
    A pioneer in bioelectronics, Rogers is the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Neurological Surgery at Northwestern’s McCormick School of Engineering and Feinberg School of Medicine and the director of the Querrey Simpson Institute for Bioelectronics (QSIB). Huang is the Jan and Marcia Achenbach Professor of Mechanical Engineering and Civil and Environmental Engineering at McCormick and key member of QSIB. More

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    Researchers teleport quantum information across rudimentary quantum network

    Researchers in Delft have succeeded in teleporting quantum information across a rudimentary network. This first of its kind is an important step towards a future quantum Internet. This breakthrough was made possible by a greatly improved quantum memory and enhanced quality of the quantum links between the three nodes of the network. The researchers, working at QuTech — a collaboration between Delft University of Technology and the Netherlands Organisation for Applied Scientific Research (TNO) — are publishing their findings today in the scientific journal Nature.
    The power of a future quantum Internet is based on the ability to send quantum information (quantum bits) between the nodes of the network. This will enable all kinds of applications such as securely sharing confidential information, linking several quantum computers together to increase their computing capability, and the use of highly precise, linked quantum sensors.
    Sending quantum information
    The nodes of such a quantum network consist of small quantum processors. Sending quantum information between these processors is no easy feat. One possibility is to send quantum bits using light particles but, due to the inevitable losses in glass fibre cables, in particular over long distances, the light particles will very likely not reach their destination. As it is fundamentally impossible to simply copy quantum bits, the loss of a light particle means that the quantum information is irrecoverably lost.
    Teleportation offers a better way of sending quantum information. The protocol for quantum teleportation owes its name to similarities with teleportation in science-fiction films: the quantum bit disappears on the side of the sender and appears on the side of the receiver. As the quantum bit therefore does not need to travel across the intervening space, there is no chance that it will be lost. This makes quantum teleportation an crucial technique for a future quantum Internet.
    Good control over the system
    In order to be able to teleport quantum bits, several ingredients are required: a quantum entangled link between the sender and receiver, a reliable method for reading out quantum processors, and the capacity to temporarily store quantum bits. Previous research at QuTech demonstrated that it is possible to teleport quantum bits between two adjacent nodes. The researchers at QuTech have now shown for the first time that they can meet the package of requirements and have demonstrated teleportation between non-adjacent nodes, in other words over a network. They teleported quantum bits from node “Charlie” to node “Alice,” with the help of an intermediate node “Bob.” More

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    Roboticists go off road to compile data that could train self-driving ATVs

    Researchers from Carnegie Mellon University took an all-terrain vehicle on wild rides through tall grass, loose gravel and mud to gather data about how the ATV interacted with a challenging, off-road environment.
    They drove the heavily instrumented ATV aggressively at speeds up to 30 miles an hour. They slid through turns, took it up and down hills, and even got it stuck in the mud — all while gathering data such as video, the speed of each wheel and the amount of suspension shock travel from seven types of sensors.
    The resulting dataset, called TartanDrive, includes about 200,000 of these real-world interactions. The researchers believe the data is the largest real-world, multimodal, off-road driving dataset, both in terms of the number of interactions and types of sensors. The five hours of data could be useful for training a self-driving vehicle to navigate off road.
    “Unlike autonomous street driving, off-road driving is more challenging because you have to understand the dynamics of the terrain in order to drive safely and to drive faster,” said Wenshan Wang, a project scientist in the Robotics Institute (RI).
    Previous work on off-road driving has often involved annotated maps, which provide labels such as mud, grass, vegetation or water to help the robot understand the terrain. But that sort of information isn’t often available and, even when it is, might not be useful. A map area labeled as “mud,” for example, may or may not be drivable. Robots that understand dynamics can reason about the physical world.
    The research team found that the multimodal sensor data they gathered for TartanDrive enabled them to build prediction models superior to those developed with simpler, nondynamic data. Driving aggressively also pushed the ATV into a performance realm where an understanding of dynamics became essential, said Samuel Triest, a second-year master’s student in robotics.
    “The dynamics of these systems tend to get more challenging as you add more speed,” said Triest, who was lead author on the team’s resulting paper. “You drive faster, you bounce off more stuff. A lot of the data we were interested in gathering was this more aggressive driving, more challenging slopes and thicker vegetation because that’s where some of the simpler rules start breaking down.”
    Though most work on self-driving vehicles focuses on street driving, the first applications likely will be off road in controlled access areas, where the risk of collisions with people or other vehicles is limited. The team’s tests were performed at a site near Pittsburgh that CMU’s National Robotics Engineering Center uses to test autonomous off-road vehicles. Humans drove the ATV, though they used a drive-by-wire system to control steering and speed.
    “We were forcing the human to go through the same control interface as the robot would,” Wang said. “In that way, the actions the human takes can be used directly as input for how the robot should act.”
    Triest will present the TartanDrive study at the International Conference on Robotics and Automation (ICRA) this week in Philadelphia. In addition to Triest and Wang, the research team included Sebastian Scherer, associate research professor in the RI; Aaron Johnson, an assistant professor of mechanical engineering; Sean J. Wang, a Ph.D. student in mechanical engineering; and Matthew Sivaprakasam, a computer engineering student at the University of Pittsburgh.
    Story Source:
    Materials provided by Carnegie Mellon University. Original written by Byron Spice. Note: Content may be edited for style and length. More

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    Toward error-free quantum computing

    For quantum computers to be useful in practice, errors must be detected and corrected. At the University of Innsbruck, Austria, a team of experimental physicists has now implemented a universal set of computational operations on fault-tolerant quantum bits for the first time, demonstrating how an algorithm can be programmed on a quantum computer so that errors do not spoil the result.
    In modern computers errors during processing and storage of information have become a rarity due to high-quality fabrication. However, for critical applications, where even single errors can have serious effects, error correction mechanisms based on redundancy of the processed data are still used.
    Quantum computers are inherently much more susceptible to disturbances and will thus probably always require error correction mechanisms, because otherwise errors will propagate uncontrolled in the system and information will be lost. Because the fundamental laws of quantum mechanics forbid copying quantum information, redundancy can be achieved by distributing logical quantum information into an entangled state of several physical systems, for example multiple individual atoms.
    The team led by Thomas Monz of the Department of Experimental Physics at the University of Innsbruck and Markus Müller of RWTH Aachen University and Forschungszentrum Jülich in Germany has now succeeded for the first time in realizing a set of computational operations on two logical quantum bits that can be used to implement any possible operation. “For a real-world quantum computer, we need a universal set of gates with which we can program all algorithms,” explains Lukas Postler, an experimental physicist from Innsbruck.
    Fundamental quantum operation realized
    The team of researchers implemented this universal gate set on an ion trap quantum computer featuring 16 trapped atoms. The quantum information was stored in two logical quantum bits, each distributed over seven atoms. More

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    Secure communication with light particles

    While quantum computers offer many novel possibilities, they also pose a threat to internet security since these supercomputers make common encryption methods vulnerable. Based on the so-called quantum key distribution, researchers at TU Darmstadt have developed a new, tap-proof communication network.
    The new system is used to exchange symmetric keys between parties in order to encrypt messages so that they cannot be read by third parties. In cooperation with Deutsche Telekom, the researchers led by physics professor Thomas Walther succeeded in operating a quantum network that is scalable in terms of the number of users and at the same time robust without the need for trusted nodes. In the future, such systems could protect critical infrastructure from the growing danger of cyberattacks. In addition, tap-proof connections could be installed between different government sites in larger cities.
    The system developed by the Darmstadt researchers enables the so-called quantum key exchange, providing several parties in a star-shaped network with a common random number. Individual light quanta, so-called photons, are distributed to users in the communication network in order to calculate the random number and thus the digital key. Due to quantum physical effects, these keys are particularly secure. In this way, communication is particularly highly protected, and existing eavesdropping attacks can be detected.
    So far, such quantum key methods have been technically complex and sensitive to external influences. The system of the Darmstadt group from the Collaborative Research Center CROSSING is based on a special protocol. The system distributes photons from a central source to all users in the network and establishes the security of the quantum keys through the effect of so-called quantum entanglement. This quantum-physical effect produces correlations between two light particles, which are observable even when they are far apart. The property of the partner particle can be predicted by measuring a property of the light particle from a pair.
    Polarization is often used as a property, but this is typically disturbed in the glass fibers used for transmission due to environmental influences such as vibrations or small temperature changes. However, the Darmstadt system uses a protocol in which the quantum information is encoded in the phase and arrival time of the photons and is therefore particularly insensitive to such disturbances. For the first time, the group has succeeded in providing a network of users with quantum keys by means of this robust protocol.
    The high stability of the transmission and the scalability in principle were successfully demonstrated in a field test together with Deutsche Telekom Technik GmbH. As a next step, the researchers at TU Darmstadt are planning to connect other buildings in the city to their system.
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    Materials provided by Technische Universitat Darmstadt. Note: Content may be edited for style and length. More

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    AI can predict cancer risk of lung nodules

    An artificial intelligence (AI) tool helps doctors predict the cancer risk in lung nodules seen on CT, according to a new study published in the journal Radiology.
    Pulmonary nodules appear as small spots on the lungs on chest imaging. They have become a much more common finding as CT has gained favor over X-rays for chest imaging.
    “A nodule would appear on somewhere between 5% to 8% of chest X-rays,” said study senior author Anil Vachani, M.D., director of clinical research in the section of Interventional Pulmonology and Thoracic Oncology at the Perelman School of Medicine, University of Pennsylvania in Philadelphia. “Chest CT is such a sensitive test, you’ll see a small nodule in upwards of a third to a half of cases. We’ve gone from a problem that was relatively uncommon to one that affects 1.6 million people in the U.S. every year.”
    Dr. Vachani and colleagues evaluated an AI-based computer-aided diagnosis tool developed by Optellum Ltd. of Oxford, England, to assist clinicians in assessing pulmonary nodules on chest CT. While CT scans show many aspects of the nodule, such as size and border characteristics, AI can delve even deeper.
    “AI can go through very large datasets to come up with unique patterns that can’t be seen through the naked eye and end up being predictive of malignancy,” Dr. Vachani said.
    In the study, six radiologists and six pulmonologists made estimates of malignancy risk for nodules using CT imaging data alone. They also made management recommendations such as CT surveillance or a diagnostic procedure for each case without and with the AI tool.
    A total of 300 chest CTs of indeterminant pulmonary nodules were used in the study. The researchers defined indeterminant nodules as those between 5 and 30 millimeters in diameter.
    Analysis showed that use of the AI tool improved estimation of nodule malignancy risk on chest CT. It also improved agreement among the different readers for both risk stratification and management recommendations.
    “The readers judge malignant or benign with a reasonable level of accuracy based on imaging itself, but when you combine their clinical interpretation with the AI algorithm, the accuracy level improves significantly,” Dr. Vachani said. “The level of improvement suggests that this tool has the potential to change how we judge cancer versus benign and hopefully improve how we manage patients.”
    The model appears to work equally well on diagnostic CT and low-dose screening CT, Dr. Vachani said, but more study is needed before the AI tool can be used in the clinic.
    “We’ve taken the first step here and shown that decision making is better if the AI tool is incorporated into radiology or pulmonology practice,” Dr. Vachani said. “The next step is to take the tool and do some prospective trials where physicians use the AI tool in a real-world setting. We are in the process of designing those trials.”
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    Materials provided by Radiological Society of North America. Note: Content may be edited for style and length. More