Computers Math

Researchers at Linköping University have developed a method that may lead to new types of displays based on structural colours. The discovery opens the way to cheap and energy-efficient colour displays and electronic labels. The study has been published in the scientific journal Advanced Materials.
We usually think of colours as created by pigments, which absorb light at certain wavelengths such that we perceive colour from other wavelengths that are scattered and reach our eyes. That’s why leaves, for example, are green and tomatoes red. But colours can be created in other ways, and some materials appear coloured due to their structure. Structural colours can arise when light is internally reflected inside the material on a scale of nanometres. This is usually referred to as interference effects. An example found in nature are peacock feathers, which are fundamentally brown but acquire their characteristic blue-green sheen from small structural features.
Researchers at Linköping University have developed a new and simple method to create structural colours for use with reflective colour displays. The new method may enable manufacturing of thin and lightweight displays with high energy-efficiency for a broad range of applications.
Reflective colour displays differ from the colour displays we see in everyday life on devices such as mobile phones and computers. The latter consist of small light-emitting diodes of red, green and blue positioned close to each other such that they together create white light. The colour of each light-emitting diode depends on the molecules from which it is built, or in other words, its pigment. However, it is relatively expensive to manufacture light-emitting diodes, and the global use of emissive displays consumes a lot of energy. Another type of display, reflective displays, is therefore being explored for purposes such as tablet computers used as e-readers, and electronic labels. Reflective displays form images by controlling how incident light from the surroundings is reflected, which means that they do not need their own source of illumination. However, most reflective displays are intrinsically monochrome, and attempts to create colour versions have been rather complicated and have sometimes given poor results.
Shangzhi Chen is a newly promoted doctor at the Laboratory of Organic Electronics at Linköping University and principal author of an article that describes a new type of dynamic structural colour image, published in the scientific journal Advanced Materials.
“We have developed a simple method to produce structural colour images with electrically conducting plastics, or conducting polymers. The polymer is applied at nanoscale thicknesses onto a mirror by a technique known as vapour phase polymerisation, after the substrate has been illuminated with UV light. The stronger the UV illumination, the thicker the polymer film, and this allows us to control the structural colours that appear at different locations on the substrate,” says Shangzhi Chen.
The method can produce all colours in the visible spectrum. Furthermore, the colours can be subsequently adjusted using electrochemical variation of the redox state of the polymer. This function has been popular for monochrome reflective displays, and the new study shows that the same materials can provide dynamic images in colour using optical interference effects combined with spatial control of nanoscale thicknesses. Magnus Jonsson, associate professor at the Laboratory of Organic Electronics at Linköping University, believes that the method has great potential, for example, for applications such as electronic labels in colour. Further research may also allow more advanced displays to be manufactured.
“We receive increasing amounts of information via digital displays, and if we can contribute to more people gaining access to information through cheap and energy-efficient displays, that would be a major benefit. But much research remains to be done, and new projects are already under way,” says Magnus Jonsson.
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Materials provided by Linköping University. Original written by Anders Ryttarson Törneholm. Note: Content may be edited for style and length. More

Synthetic biology offers a way to engineer cells to perform novel functions, such as glowing with fluorescent light when they detect a certain chemical. Usually, this is done by altering cells so they express genes that can be triggered by a certain input.
However, there is often a long lag time between an event such as detecting a molecule and the resulting output, because of the time required for cells to transcribe and translate the necessary genes. MIT synthetic biologists have now developed an alternative approach to designing such circuits, which relies exclusively on fast, reversible protein-protein interactions. This means that there’s no waiting for genes to be transcribed or translated into proteins, so circuits can be turned on much faster — within seconds.
“We now have a methodology for designing protein interactions that occur at a very fast timescale, which no one has been able to develop systematically. We’re getting to the point of being able to engineer any function at timescales of a few seconds or less,” says Deepak Mishra, a research associate in MIT’s Department of Biological Engineering and the lead author of the new study.
This kind of circuit could be useful for creating environmental sensors or diagnostics that could reveal disease states or imminent events such as a heart attack, the researchers say.
Ron Weiss, a professor of biological engineering and of electrical engineering and computer science, is the senior author of the study, which appears today in Science. Other authors include Tristan Bepler, a former MIT postdoc; Bonnie Berger, the Simons Professor of Mathematics and head of the Computation and Biology group in MIT’s Computer Science and Artificial Intelligence Laboratory; Brian Teague, an assistant professor at the University of Wisconsin; and Jim Broach, chair of the Department of Biochemistry and Molecular Biology at Penn State Hershey Medical Center.
Protein interactions
Inside living cells, protein-protein interactions are essential steps in many signaling pathways, including those involved in immune cell activation and responses to hormones or other signals. Many of these interactions involve one protein activating or deactivating another by adding or removing chemical groups called phosphates. More

During neuropsychological assessments, participants complete tasks designed to study memory and thinking. Based on their performance, the participants receive a score that researchers use to evaluate how well specific domains of their cognition are functioning.
Consider, though, two participants who achieve the same score on one of these paper-and-pencil neuropsychological tests. One took 60 seconds to complete the task and was writing the entire time; the other spent three minutes, and alternated between writing answers and staring off into space. If researchers analyzed only the overall score of these two participants, would they be missing something important?
“By looking only at the outcome, meaning what score someone gets, we lose a lot of important information about how the person performed the task that may help us to better understand the underlying problem,” explains lead author Stacy Andersen, PhD, assistant professor of medicine at Boston University School of Medicine (BUSM).
Researchers with the Long Life Family Study (LLFS) used digital pens and digital voice recorders to capture differences in study participants’ performance while completing a cognitive test and found that differences in ‘thinking’ versus ‘writing’ time on a symbol coding test might act as clinically relevant, early biomarkers for cognitive/motor decline.
Participants in the LLFS were chosen for having multiple siblings living to very old ages. Longevity has long been associated with an increased health span and thus these families are studied to better understand contributors to healthy aging. The participants were assessed on a number of physical and cognitive measures, including a symbol coding test called the Digit Symbol Substitution Test.
This timed test requires participants to fill in numbered boxes with corresponding symbols from a given key and assesses both cognitive (attention and processing speed) and non-cognitive factors (motor speed and visual scanning). To allow researchers to collect data about how a participant went about completing the task, the participants used a digital pen while completing the test. On the tip of this pen was a small camera that tracked what and when a participant wrote. The LLFS researchers divided the output from this digital pen into ‘writing time’ (the time the participant spent writing) and ‘thinking time’ (the time not spent writing) and looked at how these changed over the course of the 90-second test.
The researchers then identified groups of participants that had similar patterns of writing time and thinking time across the course of the test. They found that although most participants had consistent writing and thinking times, there were groups of participants who got faster or slowed down. “This method of clustering allowed us to look at other similarities among the participants in each group in terms of their health and function that may be related to differences in writing and thinking time patterns,” said coauthor and lead biostatistician Benjamin Sweigart, a biostatistics doctoral student at Boston University School of Public Health. The researchers found that those who got slower in writing the symbols during the test had poorer physical function on tests of grip strength and walking speed. In contrast, those who changed speed in thinking time had poorer scores on memory and executive function tests suggesting that writing time and thinking time capture different contributors to overall performance on the test.
According to the researchers, these findings show the importance of capturing additional facets of test performance beyond test scores. “Identifying whether poor test performance is related to impaired cognitive function as opposed to impaired motor function is important for choosing the correct treatment for an individual patient” adds Andersen. “The incorporation of digital technologies amplifies our ability to detect subtle differences in test behavior and functional abilities, even on brief tests of cognitive function. Moreover, these metrics have the potential to be very early markers of dysfunction.”
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Materials provided by Boston University School of Medicine. Note: Content may be edited for style and length. More

An elegant new algorithm developed by Danish researchers can significantly reduce the resource consumption of the world’s computer servers. Computer servers are as taxing on the climate as global air traffic combined, thereby making the green transition in IT an urgent matter. The researchers, from the University of Copenhagen, expect major IT companies to deploy the algorithm immediately.
One of the flipsides of our runaway internet usage is its impact on climate due to the massive amount of electricity consumed by computer servers. Current CO2 emissions from data centres are as high as from global air traffic combined — with emissions expected to double within just a few years.
Only a handful of years have passed since Professor Mikkel Thorup was among a group of researchers behind an algorithm that addressed part of this problem by producing a groundbreaking recipe to streamline computer server workflows. Their work saved energy and resources. Tech giants including Vimeo and Google enthusiastically implemented the algorithm in their systems, with online video platform Vimeo reporting that the algorithm had reduced their bandwidth usage by a factor of eight.
Now, Thorup and two fellow UCPH researchers have perfected the already clever algorithm, making it possible to address a fundamental problem in computer systems — the fact that some servers become overloaded while other servers have capacity left — many times faster than today.
“We have found an algorithm that removes one of the major causes of overloaded servers once and for all. Our initial algorithm was a huge improvement over the way industry had been doing things, but this version is many times better and reduces resource usage to the greatest extent possible. Furthermore, it is free to use for all,” says Professor Thorup of the University of Copenhagen’s Department of Computer Science, who developed the algorithm alongside department colleagues Anders Aamand and Jakob Bæk Tejs Knudsen.
Soaring internet traffic
The algorithm addresses the problem of servers becoming overloaded as they receive more requests from clients than they have the capacity to handle. This happens as users pile in to watch a certain Vimeo video or Netflix film. As a result, systems often need to shift clients around many times to achieve a balanced distribution among servers. More

A new report that could help improve how immersive technologies such as Virtual Reality (VR) and Augmented Reality (AR) are used in healthcare education and training has been published with significant input from the University of Huddersfield.
Professor David Peebles, Director of the University’s Centre for Cognition and Neuroscience, and Huddersfield PhD graduate Matthew Pears contributed to the report — ‘Immersive technologies in healthcare training and education: Three principles for progress’ — recently published by the University of Leeds with input from range of academics, technologists and health professionals.
The principles have also been expanded upon in a letter to the prestigious journal BMJ Simulation and Technology Enhanced Learning.
The Huddersfield contribution to the report stems from research conducted over several years, which involved another former Huddersfield PhD researcher, Yeshwanth Pulijala, and Professor Eunice Ma, now with Falmouth University.
“Yeshwanth had an interest in technology and education, and in using VR for dentistry training. Matthew was looking at soft skills and situation awareness, which could be applied to investigating how dentists were able to keep a track of what was going on around them. They were similar subjects, although with different emphases, and so it seemed a natural area for collaboration.”
With only a relatively small number of dental schools in the UK, the quartet visited seven dental schools in India in early 2017, with support from travel grants from Santander Bank, to test their VR-based training materials on students. The experience gained from that visit contributed to both researchers’ PhDs, and ultimately led to the involvement of Professor Peebles and Matthew Pears in the new report.
The report argues for greater standardisation of how to use immersive technologies in healthcare training and education. As Professor Peebles explains, “It’s about developing a set of principles and guidelines for the use of immersive technology in medical treatment. Immersive technology is becoming increasingly popular and, as the technology is advancing, it’s becoming clear that there is great potential to make training more accessible and effective.
“It is important, however, that research is driven by the needs of the user and existing evidence rather than the technology. Rather than thinking ‘we have a new bit of VR or AR kit, what can we do with it?’, we should be looking at the problem that needs solving — what are the learning needs, so how do we use technology to solve it?
“Developing immersive training materials can be very time-consuming and difficult to evaluate properly. Getting surgeons and medical students to take time out to test your VR training is challenging. In our case we were lucky to have a surgeon, Professor Ashraf Ayoub, a Professor of Oral and Maxillofacial Surgery at the University of Glasgow, who granted us permission to film a surgical procedure that was then transformed into a 3D environment to train students about situation awareness while in the operating theatre.”
Professor Peebles hopes the work so far will provide a basis for more investigations that could help get the most from the potential that VR and immersive technology have to offer.
“Conducting these kinds of studies is difficult to do well, in particular getting sufficient quantitative data that allows you to rigorously evaluate them. “As the report recommends, more collaboration is required to pool technological and intellectual resources, to try to develop a set of standards and a community that works together to boost and improve research in this area.”
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Materials provided by University of Huddersfield. Note: Content may be edited for style and length. More

Psychologists from UNSW Sydney have developed a new face identification ability test that will help find facial recognition experts for a variety of police and government agencies, including contract tracing.
The Glasgow Face Matching Test 2 [GFMT2] targets high-performing facial recognition individuals known as super-recognisers, who have an extraordinary ability to memorise and recall faces.
The type of professional roles that involve face identification and that could benefit from the test include visa processors, passport issuers, border control officers, police, contract tracers, as well as security staff in private industry.
“Being able to recognise faces of friends and family is a skill that most of us take for granted,” Scientia Fellow Dr David White from UNSW Science’s School of Psychology says. “But comparing images of unfamiliar faces and deciding if they show the same person is a task that most of our participants find challenging, even passport officers with many years of experience in the task. A major finding in our field in recent years has been that some people are much better than others at identifying faces from photographs.
This is an insight that has changed the way staff are recruited, for example passport and police officers.”
The lead investigator at UNSW Sydney’s Face Research Lab says the GFMT2 test is valuable for identifying super-recognisers who have been used by the London Metropolitan Police Service in criminal investigations, and famously in the alleged poisoning of former Russian spies in Salisbury. More

There are plenty of negatives associated with smart technology — tech neck, texting and driving, blue light rays — but there is also a positive: the digital age is not making us stupid, says University of Cincinnati social/behavioral expert Anthony Chemero.
“Despite the headlines, there is no scientific evidence that shows that smartphones and digital technology harm our biological cognitive abilities,” says the UC professor of philosophy and psychology who recently co-authored a paper stating such in Nature Human Behaviour.
In the paper, Chemero and colleagues at the University of Toronto’s Rotman School of Management expound on the evolution of the digital age, explaining how smart technology supplements thinking, thus helping us to excel.
“What smartphones and digital technology seem to do instead is to change the ways in which we engage our biological cognitive abilities,” Chemero says, adding “these changes are actually cognitively beneficial.”
For example, he says, your smart phone knows the way to the baseball stadium so that you don’t have to dig out a map or ask for directions, which frees up brain energy to think about something else. The same holds true in a professional setting: “We’re not solving complex mathematical problems with pen and paper or memorizing phone numbers in 2021.”
Computers, tablets and smart phones, he says, function as an auxiliary, serving as tools which are good at memorization, calculation and storing information and presenting information when you need it.
Additionally, smart technology augments decision making skills that we would be hard pressed to accomplish on our own, says the paper’s lead author Lorenzo Cecutti, a PhD candidate at the University of Toronto. Using GPS technology on our phones, he says, can not only help us get there, but lets us choose a route based on traffic conditions. “That would be a challenging task when driving round in a new city.”
Chemero adds: “You put all this technology) together with a naked human brain and you get something that’s smarter…and the result is that we, supplemented by our technology, are actually capable of accomplishing much more complex tasks than we could with our un-supplemented biological abilities.”
While there may be other consequences to smart technology, “making us stupid is not one of them,” says Chemero.
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Materials provided by University of Cincinnati. Original written by Angela Koenig. Note: Content may be edited for style and length. More

Many insects and spiders get their uncanny ability to scurry up walls and walk upside down on ceilings with the help of specialized sticky footpads that allow them to adhere to surfaces in places where no human would dare to go.
Engineers at the University of California, Berkeley, have used the principle behind some of these footpads, called electrostatic adhesion, to create an insect-scale robot that can swerve and pivot with the agility of a cheetah, giving it the ability to traverse complex terrain and quickly avoid unexpected obstacles.
The robot is constructed from a thin, layered material that bends and contracts when an electric voltage is applied. In a 2019 paper, the research team demonstrated that this simple design can be used to create a cockroach-sized robot that can scurry across a flat surface at a rate of 20 body lengths per second, or about 1.5 miles per hour — nearly the speed of living cockroaches themselves, and the fastest relative speed of any insect-sized robot.
In a new study, the research team added two electrostatic footpads to the robot. Applying a voltage to either of the footpads increases the electrostatic force between the footpad and a surface, making that footpad stick more firmly to the surface and forcing the rest of the robot to rotate around the foot.
The two footpads give operators full control over the trajectory of the robot, and allow the robot to make turns with a centripetal acceleration that exceeds that of most insects.
“Our original robot could move very, very fast, but we could not really control whether the robot went left or right, and a lot of the time it would move randomly, because if there was a slight difference in the manufacturing process — if the robot was not symmetrical — it would veer to one side,” said Liwei Lin, a professor of mechanical engineering at UC Berkeley. “In this work, the major innovation was adding these footpads that allow it to make very, very fast turns.”
To demonstrate the robot’s agility, the research team filmed the robot navigating Lego mazes while carrying a small gas sensor and swerving to avoid falling debris. Because of its simple design, the robot can also survive being stepped on by a 120-pound human.
Small, robust robots like these could be ideal for conducting search and rescue operations or investigating other hazardous situations, such as scoping out potential gas leaks, Lin said. While the team demonstrated most of the robot’s skills while it was “tethered,” or powered and controlled through a small electrical wire, they also created an “untethered” version that can operate on battery power for up to 19 minutes and 31 meters while carrying a gas sensor.
“One of the biggest challenges today is making smaller scale robots that maintain the power and control of bigger robots,” Lin said. “With larger-scale robots, you can include a big battery and a control system, no problem. But when you try to shrink everything down to a smaller and smaller scale, the weight of those elements become difficult for the robot to carry and the robot generally moves very slowly. Our robot is very fast, quite strong, and requires very little power, allowing it to carry sensors and electronics while also carrying a battery.”
Video: https://www.youtube.com/watch?v=TmRol48_DKs
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Materials provided by University of California – Berkeley. Original written by Kara Manke. Note: Content may be edited for style and length. More