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    Smart windows can significantly reduce indoor pathogens

    Daylight passing through smart windows results in almost complete disinfection of surfaces within 24 hours while still blocking harmful ultraviolet (UV) light, according to new research from UBC’s Okanagan campus.
    Dr. Sepideh Pakpour is an Assistant Professor at UBC Okanagan’s School of Engineering. For this research, she tested four strains of hazardous bacteria — methicillin-resistance Staphylococcus aureus, Klebsiella pneumoniae, E. coli and Pseudomonas aeruginosa — using a mini-living lab set-up. The lab had smart windows, which tint dynamically based on outdoor conditions, and traditional windows with blinds. The researchers found that, compared to windows with blinds, the smart windows significantly reduce bacterial growth rate and their viability.
    In their darkest tint state, Dr. Pakpour says smart windows blocked more than 99.9 per cent of UV light, but still let in short-wavelength, high-energy daylight which acts as a disinfectant. This shorter wavelength light effectively eliminated contamination on glass, plastic and fabric surfaces.
    In contrast, traditional window blinds blocked almost all daylight, preventing surfaces from being disinfected. Blinds also collect dust and germs that get resuspended into the air whenever adjusted, with Dr. Pakpour noting previous research has shown 92 per cent of hospital curtains can get contaminated within a week of being cleaned.
    “We know that daylight kills bacteria and fungi,” she says. “But the question is, are there ways to harness that benefit in buildings, while still protecting us from glare and UV radiation? Our findings demonstrate the benefits of smart windows for disinfection, and have implications for infectious disease transmission in laboratories, health-care facilities and the buildings in which we live and work.”
    The pandemic has elevated concerns about how buildings might influence the health of the people inside. While particular attention has been paid to ventilation, cleaning and filtration, the importance of daylight has been ignored. According to research shared in a recent Harvard Business Review, office workers are pushing for “healthy buildings” as part of the return to work and consistently rank access to daylight and views among their most desired amenities. More

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    Self-organization of complex structures: A matter of time

    LMU researchers have developed a new strategy for manufacturing nanoscale structures in a time- and resource-efficient manner.
    Macromolecules such as cellular structures or virus capsids can emerge from small building blocks without external control to form complex spatial structures. This self-organization is a central feature of biological systems. But such self-organized processes are also becoming increasingly important for the building of complex nanoparticles in nanotechnological applications. In DNA origami, for instance, larger structures are created out of individual bases.
    But how can these reactions be optimized? This is the question that LMU physicist Prof. Erwin Frey and his team are investigating. The researchers have now developed an approach based on the concept of time complexity, which allows new strategies to be created for the more efficient synthesizing of complex structures, as they report in the journal PNAS.
    A concept from the computer sciences
    Time complexity originally describes problems from the field of informatics. It involves investigating how the amount of time needed by an algorithm increases when there is more data to process. When the volume of data doubles, for example, the time required could double, quadruple, or increase to an even higher power. In the worst case, the running time of the algorithm increases so much that a result can no longer be output within a reasonable timeframe.
    “We applied this concept to self-organization,” explains Frey. “Our approach was: How does the time required to build large structures change when the number of individual building blocks increases?” If we assume — analogously to the case in computing — that the requisite period of time increases by a very high power as the number of components increases, this would practically render syntheses of large structures impossible. “As such, people want to develop methods in which the time depends as little as possible on the number of components,” explains Frey.
    The LMU researchers have now carried out such time complexity analyses using computer simulations and mathematical analysis and developed a new method for manufacturing complex structures. Their theory shows that different strategies for building complex molecules have completely different time complexities — and thus also different efficiencies. Some methods are more, and others less, suitable for synthesizing complex structures in nanotechnology. “Our time complexity analysis leads to a simple but informative description of self-assembly processes in order to precisely predict how the parameters of a system must be controlled to achieve optimum efficiency,” explains Florian Gartner, a member of Frey’s group and lead author of the paper.
    The team demonstrated the practicability of the new approach using a well-known example from the field of nanotechnology: The scientists analyzed how to efficiently manufacture a highly symmetrical viral envelope. Computer simulations showed that two different assembly protocols led to high yields in a short window of time.
    A new strategy for self-organization
    When carrying out such experiments before now, scientists have relied on an experimentally complicated method that involves modifying the bond strengths between individual building blocks. “By contrast, our model is based exclusively on controlling the availability of the individual building blocks, thus offering a simpler and more effective option for regulating artificial self-organization processes,” explains Gartner. With regard to its time efficiency, the new technique is comparable, and in some cases better, than established methods. “Most of all, this schema promises to be more versatile and practical than conventional assembly strategies,” reports the physicist.
    “Our work presents a new conceptual approach to self-organization, which we are convinced will be of great interest for physics, chemistry, and biology,” summarizes Frey. “In addition, it puts forward concrete practical suggestions for new experimental protocols in nanotechnology and synthetic and molecular biology.” More

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    New models assess bridge support repairs after earthquakes

    Steel-reinforced concrete columns that support many of the world’s bridges are designed to withstand earthquakes, but always require inspection and often repair once the shaking is over.
    These repairs usually involve replacing loose concrete and fractured steel bars and adding extra materials around the damaged area to further strengthen it against future loads.
    Engineers at Rice University’s George R. Brown School of Engineering and Texas A&M University have developed an innovative computational modeling strategy to make planning these repairs more effective.
    The study by Rice postdoctoral research associate Mohammad Salehi and civil and environmental engineers Reginald DesRoches of Rice and Petros Sideris of Texas A&M appears in the journal Engineering Structures. DesRoches is also the current provost and the incoming president of Rice.
    “When we design bridges and other structures for earthquakes, the goal is collapse prevention,” DesRoches said. “But particularly in larger earthquakes, we fully expect them to be damaged. In this study, we show analytically that those damages can be repaired in a way that the original, or close to the original, performance can be achieved.”
    Their models simulate how columns are likely to respond globally (in terms of base shear and lateral displacement) and locally (with stress and strain) in future earthquakes when using various repair methods. More

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    Edge processing research takes discovery closer to use in artificial intelligence networks

    Researchers at the University of Surrey have successfully demonstrated proof-of-concept of using their multimodal transistor (MMT) in artificial neural networks, which mimic the human brain. This is an important step towards using thin-film transistors as artificial intelligence hardware and moves edge computing forward, with the prospect of reducing power needs and improving efficiency, rather than relying solely on computer chips.
    The MMT, first reported by Surrey researchers in 2020, overcomes long-standing challenges associated with transistors and can perform the same operations as more complex circuits. This latest research, published in the peer-reviewed journal Scientific Reports, uses mathematical modelling to prove the concept of using MMTs in artificial intelligence systems, which is a vital step towards manufacturing.
    Using measured and simulated transistor data, the researchers show that well-designed multimodal transistors could operate robustly as rectified linear unit-type (ReLU) activations in artificial neural networks, achieving practically identical classification accuracy as pure ReLU implementations. They used both measured and simulated MMT data to train an artificial neural network to identify handwritten numbers and compared the results with the built-in ReLU of the software. The results confirmed the potential of MMT devices for thin-film decision and classification circuits. The same approach could be used in more complex AI systems.
    Unusually, the research was led by Surrey undergraduate Isin Pesch, who worked on the project during the final year research module of her BEng (Hons) in Electronic Engineering with Nanotechnology. Covid meant she had to study remotely from her home in Turkey, but she still managed to spearhead the development, complemented by an international research team, which also included collaborators in the University of Rennes, France and UCL, London.
    Isin Pesch, lead author of the paper, which was written before she graduated in July 2021, said:
    “There is a great need for technological improvements to support the growth of low cost, large area electronics which were shown to be used in artificial intelligence applications. Thin-film transistors have a role to play in enabling high processing power with low resource use. We can now see that MMTs, a unique type of thin-film transistor, invented at the University of Surrey, have the reliability and uniformity needed to fulfil this role.”
    Dr Radu Sporea, Senior Lecturer at the University of Surrey’s Advanced Technology Institute, said:
    “These findings are a reminder of how Surrey is a leader in AI research. Many of my colleagues focus on people-centred AI and how best to maximise the benefits for humans, including how to apply these new concepts ethically. Our research at the Advanced Technology Institute takes forward the physical implementation, as a stepping stone towards powerful yet affordable next-generation hardware. It’s fantastic that collaboration is resulting in such successes with researchers involved at all levels, from undergraduates like Isin when she led this research, to seasoned experts.”
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    Materials provided by University of Surrey. Note: Content may be edited for style and length. More

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    Improving reading skills through action video games

    Decoding letters into sound is a key point in learning to read but is not enough to master it. “Reading calls upon several other essential mechanisms that we don’t necessarily think about, such as knowing how to move our eyes on the page or how to use our working memory to link words together in a coherent sentence,” points out Daphné Bavelier, a professor in the Psychology Section of the Faculty of Psychology and Educational Sciences (FPSE) at the UNIGE. “These other skills, such as vision, the deployment of attention, working memory, and cognitive flexibility, are known to be improved by action video games,” explains Angela Pasqualotto, first author of this study, which is based on her PhD thesis at the Department of Psychology and Cognitive Science of the University of Trento under the direction of Professors Venuti and De Angeli.
    A child-friendly action video game to support learning
    With this in mind, a video game was designed that combines action video games with mini games that train different executive functions, such as working memory, inhibition and cognitive flexibility, functions that are called upon during reading. “The universe of this game is an alternative world in which the child, accompanied by his Raku, a flying creature, must carry out different missions to save planets and progress in the game,” Angela Pasqualotto adds. The idea is to reproduce the components of an action game, without incorporating violence, so that it is suitable for young children. “For example, the Raku flies through a meteor shower, moving around to avoid those or aiming at them to weaken their impact, while collecting useful resources for the rest of the game, a bit like what you find in action video games.”
    The scientists then worked with 150 Italian schoolchildren aged 8 to 12, divided into two groups: the first one played the video game developed by the team, and the second one played Scratch, a game that teaches children how to code. Both games require attentional control and executive functions, but in different manners. The action video game requires children to perform tasks within a time limit such as remembering a sequence of symbols or responding only when the Raku makes a specific sound while increasing the difficulty of these tasks according to the child’s performance. Scratch, the control game, requires planning, reasoning and problem solving. Children must manipulate objects and logical structures to establish the desired programming sequence.
    “First, we tested the children’s ability to read words, non-words and paragraphs, and also we conducted an attention test that measures the child’s attentional control, a capacity we know is trained by action video games,” explains Daphne Bavelier. The children then followed the training with either the action video game or the control game, for six weeks, two hours a week under supervision at school. Children were tested at school by clinicians of the Laboratory of Observation Diagnosis and Education (UNITN).
    Long-term improvement in reading skills
    Shortly after the end of the training, the scientists repeated the tests on both groups of children. “We found a 7-fold improvement in attentional control in the children who played the action video game compared to the control group,” says Angela Pasqualotto. Even more remarkably, the research team observed a clear enhancement in reading, not only in terms of reading speed, but also in accuracy, whereas no improvement was noted for the control group. This improvement in literacy occurs even though the action video game does not require any reading activity.
    “What is particularly interesting about this study is that we carried out three further assessment tests at 6 months, 12 months and 18 months after training. On each occasion, the trained children performed better than the control group, which proves that these improvements were sustained,” Angela Pasqualotto says. Moreover, the grades in Italian of the trained children became significantly better over time, showing a virtuous improvement in learning ability. “The effects are thus long-term, in line with the action video game strengthening the ability to learn how to learn,” says Daphne Bavelier.
    Within the framework of the NCCR Evolving Language and in collaboration with Irene Altarelli (co-author of the article and researcher at LaPsyDE, University of Paris), the game will be adapted into German, French and English. “When reading, decoding is more or less difficult depending on the language. Italian, for example, is very transparent — each letter is pronounced — whereas French and English are quite opaque, resulting in rather different learning challenges. Reading in opaque languages requires the ability to learn exceptions, to learn how a variety of contexts impacts pronunciation and demands greater reliance on memorization,” comments Irene Altarelli. Will the benefits of action video games on reading acquisition extend to such complex learning environments as reading in French or English? This is the question that this study will help answer. In addition, the video game will be available entirely at home, remotely, as will the administration of reading and attention tests, in order to complement school lessons, rather than taking time out of school hours. More

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    Enhanced statistical models will aid conservation of killer whales and other species

    Ecologists need to understand wild animal behaviours in order to conserve species, but following animals around can be expensive, dangerous, or sometimes impossible in the case of animals that move underwater or into areas we can’t reach easily.
    Scientists turned to the next best thing: bio-logging devices that can be attached to animals and capture information about movement, breathing rate, heart rate, and more.
    However, retrieving an accurate picture of what a tagged animal does as it journeys through its environment requires statistical analysis, especially when it comes to animal movement, and the methods statisticians use are always evolving to make full use of the large and complex data sets that are available.
    A recent study by researchers at the Institute for the Oceans and Fisheries (IOF) and the UBC department of statistics has taken us a step closer to understanding the behaviours of northern resident killer whales by improving statistical tools useful for identifying animal behaviours that can’t be observed directly.
    “The thing we really tackled with this paper was trying to get at some of those fine-scale behaviours that aren’t that easy to model,” said Evan Sidrow, a doctoral student in the department of statistics and the study’s lead author. “It’s a matter of finding behaviours on the order of seconds — maybe 10 to 15 seconds. Usually, it’s a matter of a whale looking around, and then actively swimming for a second to get over to a new location. We are trying to observe fleeting behaviours, like a whale catching a fish.”
    The research team improved a statistical tool that is based on what is called a hidden Markov model, which is helpful for unlocking the mysteries hidden inside animal movement datasets. More

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    Bone growth inspired 'microrobots' that can create their own bone

    Inspired by the growth of bones in the skeleton, researchers at the universities of Linköping in Sweden and Okayama in Japan have developed a combination of materials that can morph into various shapes before hardening. The material is initially soft, but later hardens through a bone development process that uses the same materials found in the skeleton.
    When we are born, we have gaps in our skulls that are covered by pieces of soft connective tissue called fontanelles. It is thanks to fontanelles that our skulls can be deformed during birth and pass successfully through the birth canal. Post-birth, the fontanelle tissue gradually changes to hard bone. Now, researchers have combined materials which together resemble this natural process.
    “We want to use this for applications where materials need to have different properties at different points in time. Firstly, the material is soft and flexible, and it is then locked into place when it hardens. This material could be used in, for example, complicated bone fractures. It could also be used in microrobots — these soft microrobots could be injected into the body through a thin syringe, and then they would unfold and develop their own rigid bones,” says Edwin Jager, associate professor at the Department of Physics, Chemistry and Biology (IFM) at Linköping University.
    The idea was hatched during a research visit in Japan when materials scientist Edwin Jager met Hiroshi Kamioka and Emilio Hara, who conduct research into bones. The Japanese researchers had discovered a kind of biomolecule that could stimulate bone growth under a short period of time. Would it be possible to combine this biomolecule with Jager’s materials research, to develop new materials with variable stiffness?
    In the study that followed, published in Advanced Materials, the researchers constructed a kind of simple “microrobot,” one which can assume different shapes and change stiffness. The researchers began with a gel material called alginate. On one side of the gel, a polymer material is grown. This material is electroactive, and it changes its volume when a low voltage is applied, causing the microrobot to bend in a specified direction. On the other side of the gel, the researchers attached biomolecules that allow the soft gel material to harden. These biomolecules are extracted from the cell membrane of a kind of cell that is important for bone development. When the material is immersed in a cell culture medium — an environment that resembles the body and contains calcium and phosphor — the biomolecules make the gel mineralise and harden like bone.
    One potential application of interest to the researchers is bone healing. The idea is that the soft material, powered by the electroactive polymer, will be able to manoeuvre itself into spaces in complicated bone fractures and expand. When the material has then hardened, it can form the foundation for the construction of new bone. In their study, the researchers demonstrate that the material can wrap itself around chicken bones, and the artificial bone that subsequently develops grows together with the chicken bone.
    By making patterns in the gel, the researchers can determine how the simple microrobot will bend when voltage is applied. Perpendicular lines on the surface of the material make the robot bend in a semicircle, while diagonal lines make it bend like a corkscrew.
    “By controlling how the material turns, we can make the microrobot move in different ways, and also affect how the material unfurls in broken bones. We can embed these movements into the material’s structure, making complex programmes for steering these robots unnecessary,” says Edwin Jager.
    In order to learn more about the biocompatibility of this combination of materials, the researchers are now looking further into how its properties work together with living cells.
    The research was carried out with financial support from organisations including the Japanese Society for the Promotion of Science (JSPS) Bridge Fellowship program and KAKENHI, the Swedish Research Council, Promobilia and STINT (Swedish Foundation for International Cooperation in Research and Higher Education).
    Story Source:
    Materials provided by Linköping University. Original written by Karin Söderlund Leifler. Note: Content may be edited for style and length. More

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    How to make sure digital technology works for the public good

    The Internet of Things (IoT) is completely enmeshed in our daily lives, a network of connected laptops, phones, cars, fitness trackers — even smart toasters and refrigerators — that are increasingly able to make decisions on their own. But how to ensure that these devices benefit us, rather than exploit us or put us at risk? New work, led by Francine Berman at the University of Massachusetts Amherst, proposes a novel framework, the “impact universe,” that can help policymakers keep the public interest in focus amidst the rush to adopt ever-new digital technology.
    “How,” asks Berman, Stuart Rice Honorary Chair and Research Professor in UMass Amherst’s Manning College of Information and Computer Sciences (CICS), “can we ensure that technology works for us, rather than the other way around?” Berman, lead author of a new paper recently published in the journal Patterns, and her co-authors sketch out what they call the “impact universe” — a way for policymakers and others to think “holistically about the potential impacts of societal controls for systems and devices in the IoT.”
    One of the wonders of modern digital technology is that it increasingly makes decisions for us on its own. But, as Berman puts it, “technology needs adult supervision.”
    The impact universe is a way of holistically sketching out all the competing implications of a given technology, taking into consideration environmental, social, economic and other impacts to develop effective policy, law and other societal controls. Instead of focusing on a single desirable outcome, sustainability, say, or profit, the impact universe allows us to see that some outcomes will come at the cost of others.
    “The model reflects the messiness of real life and how we make decisions,” says Berman, but it brings clarity to that messiness so that decision makers can see and debate the tradeoffs and benefits of different social controls to regulate technology. The framework allows decisions makers to be more deliberate in their policy-making and to better focus on the common good.
    Berman is at the forefront of an emerging field called public interest technology (PIT), and she’s building an initiative at UMass Amherst that unites campus students and scholars whose work is empowered by technology and focused on social responsibility. The ultimate goal of PIT is to develop the knowledge and critical thinking needed to create a society capable of effectively managing the digital ecosystem that powers our daily lives.
    Berman’s co-authors, Emilia Cabrera, Ali Jebari and Wassim Marrakchi, were Harvard undergraduates and worked with Berman on the paper during her Radcliffe Fellowship at Harvard. The fellowship gave Berman a chance to work broadly with a multidisciplinary group of scholars and thinkers, and to appreciate the importance of designing, developing, and framing societal controls so that technology promotes the public benefit.
    “The real world is complex and there are always competing priorities,” says Berman. “Tackling this complexity head-on by taking the universe of potential technology impacts into account is critical if we want digital technologies to serve society rather than overwhelm it.”
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    Materials provided by University of Massachusetts Amherst. Note: Content may be edited for style and length. More