Aurelia Butler

University of Sussex academics have established a method of turbocharging desktop PCs to give them the same capability as supercomputers worth tens of millions of pounds.
Dr James Knight and Prof Thomas Nowotny from the University of Sussex’s School of Engineering and Informatics used the latest Graphical Processing Units (GPUs) to give a single desktop PC the capacity to simulate brain models of almost unlimited size.
The researchers believe the innovation, detailed in Nature Computational Science, will make it possible for many more researchers around the world to carry out research on large-scale brain simulation, including the investigation of neurological disorders.
Currently, the cost of supercomputers is so prohibitive they are only affordable to very large institutions and government agencies and so are not accessible for large numbers of researchers.
As well as shaving tens of millions of pounds off the costs of a supercomputer, the simulations run on the desktop PC require approximately 10 times less energy bringing a significant sustainability benefit too.
Dr Knight, Research Fellow in Computer Science at the University of Sussex, said: “I think the main benefit of our research is one of accessibility. Outside of these very large organisations, academics typically have to apply to get even limited time on a supercomputer for a particular scientific purpose. This is quite a high barrier for entry which is potentially holding back a lot of significant research.

advertisement

“Our hope for our own research now is to apply these techniques to brain-inspired machine learning so that we can help solve problems that biological brains excel at but which are currently beyond simulations.
“As well as the advances we have demonstrated in procedural connectivity in the context of GPU hardware, we also believe that there is also potential for developing new types of neuromorphic hardware built from the ground up for procedural connectivity. Key components could be implemented directly in hardware which could lead to even more truly significant compute time improvements.”
The research builds on the pioneering work of US researcher Eugene Izhikevich who pioneered a similar method for large-scale brain simulation in 2006.
At the time, computers were too slow for the method to be widely applicable meaning simulating large-scale brain models has until now only been possible for a minority of researchers privileged to have access to supercomputer systems.
The researchers applied Izhikevich’s technique to a modern GPU, with approximately 2,000 times the computing power available 15 years ago, to create a cutting-edge model of a Macaque’s visual cortex (with 4.13 × 106 neurons and 24.2 × 109 synapse) which previously could only be simulated on a supercomputer.
The researchers’ GPU accelerated spiking neural network simulator uses the large amount of computational power available on a GPU to ‘procedurally’ generate connectivity and synaptic weights ‘on the go’ as spikes are triggered — removing the need to store connectivity data in memory.
Initialization of the researchers’ model took six minutes and simulation of each biological second took 7.7 min in the ground state and 8.4 min in the resting state- up to 35 % less time than a previous supercomputer simulation. In 2018, one rack of an IBM Blue Gene/Q supercomputer initialization of the model took around five minutes and simulating one second of biological time took approximately 12 minutes.
Prof Nowotny, Professor of Informatics at the University of Sussex, said: “Large-scale simulations of spiking neural network models are an important tool for improving our understanding of the dynamics and ultimately the function of brains. However, even small mammals such as mice have on the order of 1 × 1012 synaptic connections meaning that simulations require several terabytes of data — an unrealistic memory requirement for a single desktop machine.
“This research is a game-changer for computational Neuroscience and AI researchers who can now simulate brain circuits on their local workstations, but it also allows people outside academia to turn their gaming PC into a supercomputer and run large neural networks.”

Story Source:
Materials provided by University of Sussex. Original written by Neil Vowles. Note: Content may be edited for style and length. More

A team from Nanyang Technological University, Singapore (NTU Singapore) has developed a portable device that produces high-resolution 3D images of human skin within 10 minutes.
The team said the portable skin mapping (imaging) device could be used to assess the severity of skin conditions, such as eczema and psoriasis.
3D skin mapping could be useful to clinicians, as most equipment used to assess skin conditions only provide 2D images of the skin surface. As the device also maps out the depth of the ridges and grooves of the skin at up to 2mm, it could also help with monitoring wound healing.
The device presses a specially devised film onto the subject’s skin to obtain an imprint of up to 5 by 5 centimetres, which is then subjected to an electric charge, generating a 3D image.
The researchers designed and 3D printed a prototype of their device using polylactic acid (PLA), a biodegradable bioplastic. The battery-operated device which measures 7cm by 10cm weighs only 100 grams.
The made-in-NTU prototype is developed at a fraction of the cost of devices with comparable technologies, such as optical coherence tomography (OCT) machines, which may cost thousands of dollars and weigh up to 30 kilogrammes.

advertisement

Assistant Professor Grzegorz Lisak from NTU’s School of Civil and Environmental Engineering, who led the research, said: “Our non-invasive, simple and inexpensive device could be used to complement current methods of diagnosing and treating skin diseases. In rural areas that do not have ready access to healthcare, non-medically trained personnel can make skin maps using the device and send them to physicians for assessment.”
Providing an independent comment on how the device may be useful to clinicians, Dr Yew Yik Weng, a Consultant Dermatologist at the National Skin Centre and an Assistant Professor at NTU’s Lee Kong Chian School of Medicine, said: “The technology is an interesting way to map the surface texture of human skin. It could be a useful method to map skin texture and wound healing in a 3D manner, which is especially important in research and clinical trials. As the device is battery-operated and portable, there is a lot of potential in its development into a tool for point of care assessment in clinical settings.”
Asst Prof Dr Yew added: “The device could be especially useful in studies involving wound healing, as we are currently lacking a tool that maps the length and the depth of skin ridges. Currently, we rely on photographs or measurements in our trials which could only provide a 2D assessment.”
First author of the study, Mr Fu Xiaoxu, a PhD student from NTU’s School of Civil and Environmental Engineering, said: “The 3D skin mapping device is simple to operate. On top of that, a 1.5V dry battery is all that is necessary to run the device. It is an example of a basic, yet very effective application of electrochemistry, as no expensive electronic hardware is required.”
Published in the scientific journal Analytica Chimica Acta this month, the technology was developed by Asst Prof Lisak, who is also Director of Residues & Resource Reclamation Centre at the Nanyang Environment and Water Research Institute (NEWRI) and his PhD student, Mr Fu Xiaoxu.

advertisement

The ‘golden’ solution to 3D skin mapping
The key component of the NTU device is a polymer called PEDOT:PSS , commonly used in solar panels to convert light into electricity. However, the team found a different use for its electrical conductivity — to reproduce skin patterns on gold-coated film. Gold is used as it has excellent electrical conductivity and flexibility.
To use the device, a person pushes a button to press the gold-coated film onto the subject’s skin to obtain an imprint. This causes sebum, an oily substance produced by the skin, to be transferred onto the film, creating an imprint of the skin surface.
Next, the imprint of the skin is transferred to the portable device where a set of electrodes is immersed in a solution. With another push of a button, the device triggers a flow of electric charge, causing PEDOT:PSS to be deposited on the surfaces of the gold-coated film in areas that are not covered with sebum. This results in a high-resolution 3D map of the skin, which reflects the ridges and grooves of the subject’s skin.
Using pig skin as a model, the researchers demonstrated that the technology was able to map the pattern of various wounds such as punctures, lacerations, abrasions, and incisions.
The team also showed that even the complex network of wrinkles on the back of a human hand could be captured on the film. The thin film is also flexible enough to map features on uneven skin areas, such as the creases of an elbow and fingerprints.
Asst Prof Lisak added: “The device has also proven to be effective in lifting fingerprints and gives a high-resolution 3D image of their characteristics.”
Commenting on the potential uses of the device, Asst Prof Dr Yew added: “The device may aid in fingerprint identification, which is commonly performed in forensic analysis. The device could offer a higher degree of accuracy when it comes to differentiating between similar prints, due to the 3D nature of its imagery.”
To further validate its efficacy, the team is exploring conducting clinical trials later this year to test the feasibility of their device, as well as other potential therapeutic uses. More

Purdue University innovators have created technology aimed at replacing Morse code with colored “digital characters” to modernize optical storage. They are confident the advancement will help with the explosion of remote data storage during and after the COVID-19 pandemic.
Morse code has been around since the 1830s. The familiar dots and dashes system may seem antiquated given the amount of information needed to be acquired, digitally archived and rapidly accessed every day. But those same basic dots and dashes are still used in many optical media to aid in storage.
A new technology developed at Purdue is aimed at modernizing the optical digital storage technology. This advancement allows for more data to be stored and for that data to be read at a quicker rate. The research is published in Laser & Photonics Reviews.
Rather than using the traditional dots and dashes as commonly used in these technologies, the Purdue innovators encode information in the angular position of tiny antennas, allowing them to store more data per unit area.
“The storage capacity greatly increases because it is only defined by the resolution of the sensor by which you can determine the angular positions of antennas,” said Alexander Kildishev, an associate professor of electrical and computer engineering in Purdue’s College of Engineering. “We map the antenna angles into colors, and the colors are decoded.”
Technology has aided in increasing storage space availability in optical digital storage technologies. Not all optical data storage media needs to be laser-writable or rewritable.
The majority of CDs, DVDs, and Blu-Ray discs are “stamped” and not recordable at all. This class of optical media is an essential part of disposable cold storage with a rapid access rate, long-lasting shelf life, and excellent archival capabilities.
The making of a Blu-Ray disc is based on the pressing process, where the silicon stamper replicates the same dot-and-dashes format the final disc is getting. A thin nickel coating is then added to get a negative stamp. The Blu-Rays, as well as DVDs and CDs, are just mass-produced.
“Our metasurface-based ‘optical storage’ is just like that,” said Di Wang, a former Ph.D. student who fabricated the prototype structure. “Whereas in our demo prototype, the information is ‘burnt in’ by electron-beam lithography, it could be replicated by a more scalable manufacturing process in the final product.”
This new development not only allows for more information to be stored but also increases the readout rate.
“You can put four sensors nearby, and each sensor would read its own polarization of light,” Kildishev said. “This helps increase the speed of readout of information compared to the use of a single sensor with dots and dashes.”
Future applications for this technology include security tagging and cryptography. To continue developing these capabilities, the team is looking to partner with interested parties in the industry.

Story Source:
Materials provided by Purdue University. Original written by Chris Adam. Note: Content may be edited for style and length. More

Most snakes get from A to B by bending their bodies into S-shapes and slithering forward headfirst. A few species, however — found in the deserts of North America, Africa and the Middle East — have an odder way of getting around. Known as “sidewinders,” these snakes lead with their mid-sections instead of their heads, slinking sideways across loose sand.
Scientists took a microscopic look at the skin of sidewinders to see if it plays a role in their unique method of movement. They discovered that sidewinders’ bellies are studded with tiny pits and have few, if any, of the tiny spikes found on the bellies of other snakes.
The Proceedings of the National Academy of Sciences published the discovery, which includes a mathematical model linking these distinct structures to function.
“The specialized locomotion of sidewinders evolved independently in different species in different parts of the world, suggesting that sidewinding is a good solution to a problem,” says Jennifer Rieser, assistant professor of physics at Emory University and a first author of the study. “Understanding how and why this example of convergent evolution works may allow us to adapt it for our own needs, such as building robots that can move in challenging environments.”
Co-authors of the paper include Joseph Mendelson, a herpetologist and the director of research at Zoo Atlanta; evolutionary biologist Jessica Tingle (University of California, Riverside); and physicists Daniel Goldman (Georgia Tech) and co-first author Tai-De Li (City University of New York).
Rieser’s research interests bring together the physics of soft matter — flowable materials like sand — and organismal biology. She studies how animals’ surfaces interact with the flowable materials in their environments to get around. Insights from her research may lead to improvements in human technology.

advertisement

Snakes, and other limbless locomotors, are particularly interesting to Rieser. “Even though snakes have a relatively simple body plan, they are able to navigate a variety of habitats successfully,” she says. Their long, flexible bodies are inspiring work on “snake” robots for everything from surgical procedures to search-and-rescue missions in collapsed buildings, she adds.
In a previous paper, Rieser and colleagues found that designing robots to move in serpentine ways may help them to avoid catastrophe when they collide with objects in their path.
Sidewinders offered her a chance to dig further into how nature has evolved ways to move across loose sand and other soft matter.
Most snakes tend to keep their bellies largely in contact with the ground as they slide forward, bending their bodies from their heads to their tails. A sidewinder, however, lifts its midsection off the ground, shifting it in a sideways direction.
Previous studies have hypothesized that sidewinding may allow a snake to move better on sandy slopes. “The thought is that sidewinders spread out the forces that their bodies impart to the ground as they move so that they don’t cause a sand dune to avalanche as they move across it,” Rieser explains.

advertisement

For the current paper, Rieser and her colleagues investigated whether sidewinders’ skin might also play a role in their unique movement style.
They focused on three species of sidewinders, all of them vipers, in residence at zoos: The sidewinder rattlesnake (Crotalus cerastes), found in the deserts of the Southwestern United States and northern Mexico; and the Saharan horned viper (Cerastes cerastes) and the Saharan sand viper (Cerastes vipera), both from the deserts of north Africa.
Skins shed from the sidewinders were collected and scanned with atomic force microscopy, a technique that provides resolution at the atomic level, on the order of fractions of a nanometer. For comparison, they also scanned snake skins shed from non-sidewinders.
As expected, the microscopy revealed tiny, head-to-tail pointing spikes on the skin of the non-sidewinders. Previous research had identified these micro spikes on a variety of other slithering snakes.
The current study, however, found that the skin of sidewinders is different. The two African sidewinders had micro pits on their bellies and no spikes. The skin of the sidewinder rattlesnake was also studded with tiny pits, along with a few, much smaller, spikes — although far fewer spikes than those of the slithering snakes.
The researchers created a mathematical model to test how these different structures affect frictional interactions with a surface. The model showed that head-to-tail pointing spikes enhance the speed and distance of forward undulation but are detrimental to sidewinding.
“You can think about it like the ridges on corduroy material,” Rieser says. “When you run your fingers along corduroy in the same direction as the ridges there is less friction than when you slide your fingers across the ridges.”
The model also showed that the uniform, non-directional structure of the round pits enhanced sidewinding, but was not as efficient as spikes for forward undulation.
The research provides snapshots at different points in time of convergent evolution — when different species independently evolve similar traits as a result of having to adapt to similar environments.
Rieser notes that American sandy deserts are much younger than those in Africa. The Mojave of North America accumulated sand about 20,000 years ago while sandy conditions appeared in the Sahara region at least seven million years ago.
“That may explain why the sidewinder rattlesnake still has a few micro spikes left on its belly,” she says. “It has not had as much time to evolve specialized locomotion for a sandy environment as the two African species, that have already lost all of their spikes.”
Engineers may also want to adapt their robot designs accordingly, Rieser adds. “Depending on what type of surface you need a robot to move on,” she says, “you may want to consider designing its surface to have a particular texture to enhance its movement.” More

Social media is increasingly used to spread fake news. The same problem can be found on the capital market — criminals spread fake news about companies in order to manipulate share prices. Researchers at the Universities of Göttingen and Frankfurt and the Jožef Stefan Institute in Ljubljana have developed an approach that can recognise such fake news, even when the news contents are repeatedly adapted. The results of the study were published in the Journal of the Association for Information Systems.
In order to detect false information — often fictitious data that presents a company in a positive light — the scientists used machine learning methods and created classification models that can be applied to identify suspicious messages based on their content and certain linguistic characteristics. “Here we look at other aspects of the text that makes up the message, such as the comprehensibility of the language and the mood that the text conveys,” says Professor Jan Muntermann from the University of Göttingen.
The approach is already known in principle from its use by spam filters, for example. However, the key problem with the current methods is that to avoid being recognised, fraudsters continuously adapt the content and avoid certain words that are used to identify the fake news. This is where the researchers’ new approach comes in: to identify fake news despite such strategies to evade detection, they combine models recently developed by the researchers in such a way that high detection rates and robustness come together. So even if “suspicious” words disappear from the text, the fake news is still recognised by its linguistic features. “This puts scammers into a dilemma. They can only avoid detection if they change the mood of the text so that it is negative, for instance,” explains Dr Michael Siering. “But then they would miss their target of inducing investors to buy certain stocks.”
The new approach can be used, for example, in market surveillance to temporarily suspend the trading of affected stocks. In addition, it offers investors valuable information to avoid falling for such fraud schemes. It is also possible that it could be used for criminal prosecutions in the future.

Story Source:
Materials provided by University of Göttingen. Note: Content may be edited for style and length. More

Imagine a rubber band that was capable of snapping itself many times over, or a small robot that could jump up a set of stairs propelled by nothing more than its own energy. Researchers at the University of Massachusetts Amherst have discovered how to make materials that snap and reset themselves, only relying upon energy flow from their environment. The discovery may prove useful for various industries that want to source movement sustainably, from toys to robotics, and is expected to further inform our understanding of how the natural world fuels some types of movement.
Al Crosby, a professor of polymer science and engineering in the College of Natural Sciences at UMass Amherst, and Yongjin Kim, a graduate student in Crosby’s group, along with visiting student researcher Jay Van den Berg from Delft University of Technology in the Netherlands, uncovered the physics during a mundane experiment that involved watching a gel strip dry. The researchers observed that when the long, elastic gel strip lost internal liquid due to evaporation, the strip moved. Most movements were slow, but every so often, they sped up. These faster movements were snap instabilities that continued to occur as the liquid evaporated further. Additional studies revealed that the shape of the material mattered and that the strips could reset themselves to continue their movements.
“Many plants and animals, especially small ones, use special parts that act like springs and latches to help them move really fast, much faster than animals with muscles alone,” says Crosby, when explaining the study. “Plants like the Venus flytraps are good examples of this kind of movement, as are grasshoppers and trap-jaw ants in the animal world. Snap instabilities are one way that nature combines a spring and a latch and are increasingly used to create fast movements in small robots and other devices, as well as toys like rubber poppers. However, most of these snapping devices need a motor or a human hand to keep moving. With this discovery, there could be various applications that won’t require batteries or motors to fuel movement.”
Kim explains that after learning the essential physics from the drying strips, the team experimented with different shapes to find the ones most likely to react in expected ways and that would move repeatedly without any motors or hands resetting them. The team even showed that the reshaped strips could do work, such as climb a set of stairs on their own.
Crosby continues, “These lessons demonstrate how materials can generate powerful movement by harnessing interactions with their environment, such as through evaporation, and they are important for designing new robots, especially at small sizes where it’s difficult to have motors, batteries, or other energy sources.”
These latest results from Crosby and his group are part of a larger multidisciplinary university research initiative funded by the Army Research Office, an element of the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory and led by Sheila Patek, professor of biology at Duke University, that aims to uncover many similar mechanisms from fast-moving biological organisms and translate them into new engineered devices.
“This work is part of a larger multidisciplinary effort that seeks to understand biological and engineered impulsive systems that will lay the foundations for scalable methods for generating forces for mechanical action and energy storing structures and materials,” says Ralph Anthenien, branch chief, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory. “The work will have myriad possible future applications in actuation and motive systems for the Army and DoD.”

Story Source:
Materials provided by University of Massachusetts Amherst. Note: Content may be edited for style and length. More

Researchers from North Carolina State University and the University of Texas have developed and demonstrated a new approach for designing photonic devices. The advance allows them to control the direction and polarization of light from thin-film LEDs, paving the way for a new generation of virtual reality (VR) and augmented reality (AR) technologies.
“This is a fundamentally new device architecture for photonic devices,” says Franky So, corresponding author of a paper describing the work. “And we’ve demonstrated that, using our approach, directional and polarized emissions from an organic LED or a perovskite LED without external optical elements can be realized.” So is the Walter and Ida Freeman Distinguished Professor of Materials Science and Engineering at NC State.
In practical terms, an approach that allows for directional control of light using thin-film LEDs makes it possible to develop VR and AR headsets that are substantially lighter and less bulky. And the improved efficiency of the devices means that you get more photons out of the display unit for every electron that you put in.
For AR units, it also means that more light from the outside world gets through to the user. In other words, you’ll still be able to see the image being superimposed on your view of the real world, and your view of the real world will be clearer.
“Because the device we’ve demonstrated is simple to fabricate and can be easily scaled-up, our discovery of this strong directional and polarized light emission from OLEDs and perovskite LEDs has important applications for displays, lighting and other photonic applications,” So says.

Story Source:
Materials provided by North Carolina State University. Note: Content may be edited for style and length. More