Computers Math

Athletes still have the edge over action video gamers when it comes to dynamic visual skills, a new study from the University of Waterloo shows.
For an athlete, having strong visual skills can be the difference between delivering a peak performance and achieving average results.
“Athletes involved in sports with a high-level of movement — like soccer, football, or baseball — often score higher on dynamic visual acuity tests than non-athletes,” said Dr. Kristine Dalton of Waterloo’s School of Optometry & Vision Science. “Our research team wanted to investigate if action video gamers — who, like e-sport athletes, are regularly immersed in a dynamic, fast-paced 2-D video environment for large periods of time — would also show superior levels of dynamic visual acuity on par with athletes competing in physical sport.”
While visual acuity (clarity or sharpness of vision) is most often measured under static conditions during annual check-ups with an optometrist, research shows that testing dynamic visual acuity is a more effective measure of a person’s ability to see moving objects clearly — a baseline skill necessary for success in physical and e-sports alike.
Using a dynamic visual acuity skills-test designed and validated at the University of Waterloo, researchers discovered that while physical athletes score highly on dynamic visual acuity tests as expected, action video game players tested closer to non-athletes.
“Ultimately, athletes showed a stronger ability to identify smaller moving targets, which suggests visual processing differences exist between them and our video game players,” said Alan Yee, a PhD candidate in vision science. All participants were matched based on their level of static visual acuity and refractive error, distinguishing dynamic visual acuity as the varying factor on their test performance.
These findings are also important for sports vision training centres that have been exploring the idea of developing video game-based training programs to help athletes elevate their performance.
“Our findings show there is still a benefit to training in a 3-D environment,” said Dalton. “For athletes looking to develop stronger visual skills, the broader visual field and depth perception that come with physical training may be crucial to improving their dynamic visual acuity — and ultimately, their sport performance.”
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Scientists develop groundbreaking theory for calculating what’s happening inside a proton travelling at the speed of light.
For more than 2,000 years, scientists thought the atom was the smallest particle possible. Then, they discovered that it has a nucleus made up of protons and neutrons surrounded by electrons. After that, they found that the protons and neutrons themselves have a complex inner world full of quarks and antiquarks held together by a superglue-like force created by gluons.
“Protons along with neutrons constitute over 99 percent of the visible universe, meaning everything from galaxies and stars to us,” said Yong Zhao — a physicist at the U.S. Department of Energy’s (DOE) Argonne National Laboratory. “Yet, there is still much we do not know about the rich inner life of protons or neutrons.”
Zhao has co-authored a paper on an innovative method for calculating the quark and gluon structure of a proton travelling at the speed of light. The name of the team’s creation is large-momentum effective theory, LaMET for short, which works jointly with a theory called lattice quantum chromodynamics (QCD).
The proton is tiny — about 100,000 times smaller than an atom, so physicists often model it as a point with no dimensions. But these new theories can predict what’s happening within the speed-of-light proton as though it were a body of three dimensions.
The concept of momentum is vital to not only LaMET but physics in general. It equals the speed of an object times its mass. More

LEO carves out a new type of locomotion somewhere between walking and flying.
Researchers at Caltech have built a bipedal robot that combines walking with flying to create a new type of locomotion, making it exceptionally nimble and capable of complex movements.
Part walking robot, part flying drone, the newly developed LEONARDO (short for LEgs ONboARD drOne, or LEO for short) can walk a slackline, hop, and even ride a skateboard. Developed by a team at Caltech’s Center for Autonomous Systems and Technologies (CAST), LEO is the first robot that uses multi-joint legs and propeller-based thrusters to achieve a fine degree of control over its balance.
A paper about the LEO robot was published online on October 6 and was featured on the October 2021 cover of Science Robotics.
“We drew inspiration from nature. Think about the way birds are able to flap and hop to navigate telephone lines,” says Soon-Jo Chung, corresponding author and Bren Professor of Aerospace and Control and Dynamical Systems. “A complex yet intriguing behavior happens as birds move between walking and flying. We wanted to understand and learn from that.”
“There is a similarity between how a human wearing a jet suit controls their legs and feet when landing or taking off and how LEO uses synchronized control of distributed propeller-based thrusters and leg joints,” Chung adds. “We wanted to study the interface of walking and flying from the dynamics and control standpoint.”
Bipedal robots are able to tackle complex real-world terrains by using the same sort of movements that humans use, like jumping or running or even climbing stairs, but they are stymied by rough terrain. Flying robots easily navigate tough terrain by simply avoiding the ground, but they face their own set of limitations: high energy consumption during flight and limited payload capacity. “Robots with a multimodal locomotion ability are able to move through challenging environments more efficiently than traditional robots by appropriately switching between their available means of movement. In particular, LEO aims to bridge the gap between the two disparate domains of aerial and bipedal locomotion that are not typically intertwined in existing robotic systems,” says Kyunam Kim, postdoctoral researcher at Caltech and co-lead author of the Science Robotics paper. More

A team of scientists from Germany, Sweden and China has discovered a new physical phenomenon: complex braided structures made of tiny magnetic vortices known as skyrmions. Skyrmions were first detected experimentally a little over a decade ago and have since been the subject of numerous studies, as well as providing a possible basis for innovative concepts in information processing that offer better performance and lower energy consumption. Furthermore, skyrmions influence the magnetoresistive and thermodynamic properties of a material. The discovery therefore has relevance for both applied and basic research.
Strings, threads and braided structures can be seen everywhere in daily life, from shoelaces, to woollen pullovers, from plaits in a child’s hair to the braided steel cables that are used to support countless bridges. These structures are also commonly seen in nature and can, for example, give plant fibres tensile or flexural strength. Physicists at Forschungszentrum Jülich, together with colleagues from Stockholm and Hefei, have discovered that such structures exist on the nanoscale in alloys of iron and the metalloid germanium.
These nanostrings are each made up of several skyrmions that are twisted together to a greater or lesser extent, rather like the strands of a rope. Each skyrmion itself consists of magnetic moments that point in different directions and together take the form of an elongated tiny vortex. An individual skyrmion strand has a diamater of less than one micrometre. The length of the magnetic structures is limited only by the thickness of the sample; they extend from one surface of the sample to the opposite surface.
Earlier studies by other scientists had shown that such filaments are largely linear and almost rod-shaped. However, ultra-high-resolution microscopy investigations undertaken at the Ernst Ruska-Centre in Jülich the theoretical studies at Jülich’s Peter Grünberg Institute have revealed a more varied picture: the threads can in fact twist together to varying degrees. According to the researchers, these complex shapes stabilise the magnetic structures, making them particularly interesting for use in a range of applications.
“Mathematics contains a great variety of these structures. Now we know that this theoretical knowledge can be translated into real physical phenomena,” Jülich physicist Dr. Nikolai Kiselev is pleased to report. “These types of structures inside magnetic solids suggest unique electrical and magnetic properties. However, further research is needed to verify this.”
To explain the discrepancy between these studies and previous ones, the researcher points out that analyses using an ultra-high-resolution electron microscope do not simply provide an image of the sample, as in the case of, for example, an optical microscope. This is because quantum mechanical phenomena come into play when the high energy electrons interact with those in the sample.
“It is quite feasible that other researchers have also seen these structures under the microscope, but have been unable to interpret them. This is because it is not possible to directly determine the distribution of magnetization directions in the sample from the data obtained. Instead, it is necessary to create a theoretical model of the sample and to generate a kind of electron microscope image from it,” explains Kiselev. “If the theoretical and experimental images match, one can conclude that the model is able to represent reality.” In ultra-high-resolution analyses of this kind, Forschungszentrum Jülich with its Ernst Ruska-Centre counts as one of the leading institutions worldwide.
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The new study found that by tweaking the electrical properties of individual cells in simulations of brain networks, the networks learned faster than simulations with identical cells.
They also found that the networks needed fewer of the tweaked cells to get the same results, and that the method is less energy intensive than models with identical cells.
The authors say that their findings could teach us about why our brains are so good at learning, and might also help us to build better artificially intelligent systems, such as digital assistants that can recognise voices and faces, or self-driving car technology.
First author Nicolas Perez, a PhD student at Imperial College London’s Department of Electrical and Electronic Engineering, said: “The brain needs to be energy efficient while still being able to excel at solving complex tasks. Our work suggests that having a diversity of neurons in both brains and AI systems fulfils both these requirements and could boost learning.”
The research is published in Nature Communications.
Why is a neuron like a snowflake?
The brain is made up of billions of cells called neurons, which are connected by vast ‘neural networks’ that allow us to learn about the world. Neurons are like snowflakes: they look the same from a distance but on further inspection it’s clear that no two are exactly alike. More

Reservoir computing (RC) tackles complex problems by mimicking the way information is processed in animal brains. It relies on a randomly connected network that serves as a reservoir for information and ultimately leads to more efficient outputs. For realizing RC directly in matter (instead of simulating it in a digital computer), numerous reservoir materials have been investigated to date. Now a team including researchers from Osaka University has designed a sulfonated polyaniline network for RC.
Neural networks in the brain use electrochemical signals carried by ions. Therefore, an electrochemical approach is a logical choice when choosing a material system for RC. Organic electrochemical field-effect transistors (OECFETs) are popular in bioelectronics; however, they have not yet been widely used for RC.
The key to the reservoir material is that it has rich (time-dependent) behavior and is disordered, which makes polymer materials an excellent option as they form random networks by themselves.
Polyaniline is a promising polymer for RC applications, because it is easy to polymerize, has good stability in the atmosphere, and has reversible doping/de-doping behavior, which means its conduction can be altered.
The researchers investigated sulfonated polyaniline (SPAN), which, in addition to the advantages of polyaniline, has high water-solubility and self-doping behavior. These make SPAN easier to work with and the doping more uniform.
“Atmospheric protons are injected directly into the polymer chain of SPAN, which causes it to conduct,” explains study lead author Yuki Usami. “This conduction can then be controlled by adjusting the humidity.”
The researchers used a simple drop-casting method to assemble the SPAN on gold electrodes to give an organic electrochemical network device (OEND).
The SPAN OEND was tested for RC by checking the waveform and assessing its performance in short-term memory tasks. Results of a test to see how well speech could be recognized achieved 70% accuracy. This ability of SPAN OEND was comparable with a software simulation of RC.
“We have shown that our SPAN OEND system can be applied in RC,” says study corresponding author Takuya Matsumoto. “Future steps to establish systems that do not rely on humidity will provide more practical options; however, the success of our SPAN-based system is a positive step for material-based reservoir computing, which is expected to have a significant impact on the next generation of artificial intelligence devices.”
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Imagine a team of autonomous drones equipped with advanced sensing equipment, searching for smoke as they fly high above the Sierra Nevada mountains. Once they spot a wildfire, these leader robots relay directions to a swarm of firefighting drones that speed to the site of the blaze.
But what would happen if one or more leader robots was hacked by a malicious agent and began sending incorrect directions? As follower robots are led farther from the fire, how would they know they had been duped?
The use of blockchain technology as a communication tool for a team of robots could provide security and safeguard against deception, according to a study by researchers at MIT and Polytechnic University of Madrid, which was published today in IEEE Transactions on Robotics. The research may also have applications in cities where multirobot systems of self-driving cars are delivering goods and moving people across town.
A blockchain offers a tamper-proof record of all transactions — in this case, the messages issued by robot team leaders — so follower robots can eventually identify inconsistencies in the information trail.
Leaders use tokens to signal movements and add transactions to the chain, and forfeit their tokens when they are caught in a lie, so this transaction-based communications system limits the number of lies a hacked robot could spread, according to Eduardo Castelló, a Marie Curie Fellow in the MIT Media Lab and lead author of the paper.
“The world of blockchain beyond the discourse about cryptocurrency has many things under the hood that can create new ways of understanding security protocols,” Castelló says. More

Electrical engineers at Duke University have discovered that changing the physical shape of a class of materials commonly used in electronics and near- and mid-infrared photonics — chalcogenide glasses — can extend their use into the visible and ultraviolet parts of electromagnetic spectrum. Already commercially used in detectors, lenses and optical fibers, chalcogenide glasses may now find a home in applications such as underwater communications, environmental monitoring and biological imaging.
The results appear online on October 5 in the journal Nature Communications.
As the name implies, chalcogenide glasses contain one or more chalcogens — chemical elements such as sulfur, selenium and tellurium. But there’s one member of the family they leave out: oxygen. Their material properties make them a strong choice for advanced electronic applications such as optical switching, ultra-small direct laser writing (think tiny rewritable CDs) and molecular fingerprinting. But because they strongly absorb wavelengths of light in the visible and ultraviolet parts of electromagnetic spectrum, chalcogenide glasses have long been constrained to the near- and mid-infrared with respect to their applications in photonics.
“Chalcogenides have been used in the near- and mid-IR for a long time, but they’ve always had this fundamental limitation of being lossy at visible and UV wavelengths,” said Natalia Litchinitser, professor of electrical and computer engineering at Duke. “But recent research into how nanostructures affect the way these materials respond to light indicated that there might be a way around these limitations.”
In recent theoretical research into the properties of gallium arsenide (GaAs), a semiconductor commonly used in electronics, Litchinitser’ s collaborators, Michael Scalora of the US Army CCDC Aviation and Missile Center and Maria Vincenti of the University of Brescia predicted that nanostructured GaAs might respond to light differently than its bulk or even thin film counterparts. Because of the way that high intensity optical pulses interact with the nanostructured material, very thin wires of the material lined up next to one another might create higher-order harmonic frequencies (shorter wavelengths) that could travel through them.
Imagine a guitar string that is tuned to resonate at 256 Hertz — otherwise known as middle C. The researchers were proposing that if fabricated just right, this string when plucked might also vibrate at frequencies one or two octaves higher in small amounts. More