Computers Math

Robotics and wearable devices might soon get a little smarter with the addition of a stretchy, wearable synaptic transistor developed by Penn State engineers. The device works like neurons in the brain to send signals to some cells and inhibit others in order to enhance and weaken the devices’ memories.
Led by Cunjiang Yu, Dorothy Quiggle Career Development Associate Professor of Engineering Science and Mechanics and associate professor of biomedical engineering and of materials science and engineering, the team designed the synaptic transistor to be integrated in robots or wearables and use artificial intelligence to optimize functions. The details were published on Sept. 29 in Nature Electronics.
“Mirroring the human brain, robots and wearable devices using the synaptic transistor can use its artificial neurons to ‘learn’ and adapt their behaviors,” Yu said. “For example, if we burn our hand on a stove, it hurts, and we know to avoid touching it next time. The same results will be possible for devices that use the synaptic transistor, as the artificial intelligence is able to ‘learn’ and adapt to its environment.”
According to Yu, the artificial neurons in the device were designed to perform like neurons in the ventral tegmental area, a tiny segment of the human brain located in the uppermost part of the brain stem. Neurons process and transmit information by releasing neurotransmitters at their synapses, typically located at the neural cell ends. Excitatory neurotransmitters trigger the activity of other neurons and are associated with enhancing memories, while inhibitory neurotransmitters reduce the activity of other neurons and are associated with weakening memories.
“Unlike all other areas of the brain, neurons in the ventral tegmental area are capable of releasing both excitatory and inhibitory neurotransmitters at the same time,” Yu said. “By designing the synaptic transistor to operate with both synaptic behaviors simultaneously, fewer transistors are needed compared to conventional integrated electronics technology, which simplifies the system architecture and allows the device to conserve energy.”
To model soft, stretchy biological tissues, the researchers used stretchable bilayer semiconductor materials to fabricate the device, allowing it to stretch and twist while in use, according to Yu. Conventional transistors, on the other hand, are rigid and will break when deformed.
“The transistor is mechanically deformable and functionally reconfigurable, yet still retains its functions when stretched extensively,” Yu said. “It can attach to a robot or wearable device to serve as their outermost skin.”
In addition to Yu, other contributors include Hyunseok Shim and Shubham Patel, Penn State Department of Engineering Science and Mechanics; Yongcao Zhang, the University of Houston Materials Science and Engineering Program; Faheem Ershad, Penn State Department of Biomedical Engineering and University of Houston Department of Biomedical Engineering; Binghao Wang, School of Electronic Science and Engineering, Southeast University and Department of Chemistry and the Materials Research Center, Northwestern University; Zhihua Chen, Flexterra Inc.; Tobin J. Marks, Department of Chemistry and the Materials Research Center, Northwestern University; Antonio Facchetti, Flexterra Inc. and Northwestern University’s Department of Chemistry and Materials Research Center.
The Office of Naval Research, the Air Force Office of Scientific Research and the National Science Foundation supported this work.
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Materials provided by Penn State. Original written by Mariah Chuprinski. Note: Content may be edited for style and length. More

Researchers in public policy and education recently found that young adults who use more social media are significantly more likely to develop depression within six months, regardless of personality type.
Published in the Journal of Affective Disorders Reports, the study, “Associations between social media use, personality structure, and development of depression,” was co-authored by Renae Merrill, a doctoral student in the Public Policy Program at the University of Arkansas.
Merrill wrote the paper with dean of the College of Public Health and Human Sciences at Oregon State University, Brian Primack, and Chunhua Cao, an assistant professor in the College of Education at the University of Alabama.
“Previous research has linked the development of depression with numerous factors,” the authors noted. “However, the literature has been lacking in studies that focus on how various personality characteristics may interact with social media use and depression. This new study addressed these important research questions, finding strong and linear associations of depression across all personality traits.”
Among the study’s findings was that people with high agreeableness were 49 percent less likely to become depressed than people with low agreeableness. Additionally, those with high neuroticism were twice as likely to develop depression than those with low neuroticism when using more than 300 minutes of social media per day. More importantly, for each personality trait, social media use was strongly associated with the development of depression.
The sample of more than 1,000 U.S. adults between the ages of 18 to 30 was from 2018 data collected by Primack and his colleagues at the University of Pittsburgh.
Depression was measured using the Patient Health Questionnaire. Social media was measured by asking participants how much daily time was spent using popular social media platforms, and personality was measured using the Big Five Inventory, which assessed openness, conscientiousness, extraversion, agreeableness and neuroticism.
The authors suggest that problematic social comparison can enhance negative feelings of oneself and others, which could explain how risk of depression increases with increased social media use. Engaging primarily in negative content can also enhance these feelings. And lastly, engaging in more social media reduces opportunities for in-person interactions and activities outside of the home.
Depression has been noted as the leading cause of disability and mortality worldwide. This makes these findings even more pronounced for creating health interventions and prevention efforts.
“Findings from this study are important during a time of technology expansion and integration,” Merrill said. “Connecting to people virtually may increase the risk of miscommunication or misperception that leads to relationship difficulties and potential risk for developing mental health problems.”
“People have innate emotional needs for social connection and understanding,” Merrill added. “For example, social media experiences can be improved by becoming more aware of our emotions and our connection with others in various life circumstances. This awareness helps improve relationship quality by simply reaching shared meaning and understanding through more effective communication and concern for others and ourselves. Despite our differences, we have the ability to create a culture of empathy and kindness.”
Research support was received by the Fine Foundation.
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If you ask someone if they are a math or science person, they may quickly tell you yes or no. It turns out that how people answer that question in ninth grade and even earlier not only can tell you what subjects they prefer in school, but how likely they are to go on to study STEM subjects in college and work in those fields as adults. The results of a new study from the University of Kansas suggest the importance of fostering positive attitudes toward math and science early in students’ life to address gender and socioeconomic gaps in STEM.
KU researchers analyzed a nationwide data set that asked students if they consider themselves a math and/or science person in ninth grade in 2009. The survey then followed up with those students in 11th grade to ask the same question, then three years after graduation to see who had enrolled in science, technology, engineering and math (STEM) majors, and whether they intended to have a related career when they turned 30. The results not only support the importance of student attitudes on academic outcomes, they also suggest efforts should be focused more on cultivating positive attitudes earlier in student careers, before they get to college, where most of such efforts happen currently.
Rafael Quintana, assistant professor of educational psychology, and Argun Saatcioglu, professor of educational policy and sociology, both at KU, conducted a study in which they analyzed data from the High School Longitudinal Study of 2009. The data set includes responses from more than 21,000 students from about 940 schools across the United States. The study was published in the journal Socius: Sociological Research for a Dynamic World.
Results showed that the odds of enrolling in a STEM major were 1.78 times larger for students with a science identity in ninth grade and 1.66 times larger for those with a math identity than those who did not identify with the subjects. The odds of expecting a career in STEM was 1.69 times larger and 1.6 times larger for those with high science and math identities, respectively.
Those numbers are illustrative of how having positive experiences with math and science early can be influential both in higher education and later in life, the researchers said.
“What do we mean when we say education has long-lasting effects? That’s something we want to think about longitudinally,” Quintana said. “Those early experiences get ‘under the skin,’ as they are related to later outcomes independently of how these attitudes developed later. What this suggests is one, the importance of identity beliefs for career-related decisions, and two, that early experiences can have long-lasting, potentially irreversible effects.”
The data also showed that, when controlling for all other variables, the odds of expecting a career in a STEM field was about 50% lower for women than men and that there was a significant interaction between science identity in school and gender when predicting STEM occupation. In other words, it was more consequential for men to identify with science in ninth grade, as they were more likely to go on to a career in the sciences. Research has long noted a gender gap and socioeconomic inequalities in STEM, but most efforts have focused on how to address them among college students. While those efforts are just, Quintana said, the study results suggest it is important to take measures to address math and science inequities earlier in life as well.
Schools can play a long-term role in helping students believe they can have a career in STEM and visualize such a possibility. By providing equitable access to math and science programs, they can also provide chances to those who may not otherwise get them, the researchers said.
“We want schools to matter and have a consequential effect,” Saatcioglu said. “If you can get kids thinking they are a math or science person through positive experiences, that can have long-term effects. If you can get students to feel that way, it can be beneficial. The key in this study was Rafael was able to isolate the long-term effects of attitudes from ninth grade.”
The attitudes students hold in early high school are key, as they have a cascading effect.
“For example, individuals’ self- perceptions can affect the courses they take, the effort and time they spend on specific subjects and the interests and aspirations they develop,” the authors wrote. “These attitudes and behaviors can shape individuals career trajectories independently of their future identity beliefs. This ramification of causal effects is what generates the cascading and potentially irreversible consequences of early-life experiences.”
Quintana, who uses longitudinal data analysis to study problems in education and human development, said he also hopes to revisit the data in the future to see where those in the data set are now, and how many are still working in STEM fields. Such analysis could also be applied to understand other early educational experiences such as bullying and how they influence later choices, attitudes and career pathways. More

Transition metals and non-ferrous metals such as copper, nickel and cobalt are not only suitable as materials in engineering and technology, but also for a wide range of applications in electrochemistry and catalysis. Their chemical and physical properties are related to the occupation of the outer d-orbital shells around the atomic nuclei. The energetic levels of the electrons as well as their localisation or delocalisation can be studied at the X-ray source BESSY II, which offers powerful synchrotron radiation.
Copper, Nickel, Cobalt
The team of the Uppsala-Berlin Joint Lab (UBjL) around Prof. Alexander Föhlisch and Prof. Nils Mårtensson has now published new results on copper, nickel and cobalt samples. They confirmed known findings for copper, whose d-electrons are atomically localised, and for nickel, in which localised electrons coexist with delocalised electrons. In the case of the element cobalt, which is used for batteries and as an alloy in fuel cells, however, previous findings were contradictory because the measurement accuracy was not sufficient to make clear statements.
Spectroscopy combined with highly sensitive detectors
At BESSY II the Uppsala-Berlin joint Lab has set up an instrument which enables measurements with the necessary precision. To determine electronic localisation or delocalisation, Auger photo-electron coincidence spectroscopy (APECS) is used. APECS requires the newly developed “Angle resolved Time of Flight” (ArTOF) electron spectrometers, whose detection efficiency exceeds that of standard hemispherical analysers by orders of magnitude. Equipped with two ArTOF electron spectrometers, the CoESCA@UE52-PGM end station supervised by UBjL scientist Dr. Danilo Kühn is unique worldwide.
Analysing (catalytical) materials
In the case of the element cobalt, the measurements now revealed that the d-electrons of cobalt can be regarded as highly delocalised. “This is an important step for a quantitative determination of electronic localisation on a variety of materials, catalysts and (electro)chemical processes,” Föhlisch points out.
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The place of artificial intelligence, AI, in our everyday life is increasing and many researchers believe that what we have seen so far is only the beginning. However, AI must be trustworthy in all situations. Linköping University is coordinating TAILOR, a EU project that has drawn up a research-based roadmap intended to guide research funding bodies and decision-makers towards the trustworthy AI of the future.
“The development of artificial intelligence is in its infancy. When we look back at what we are doing today in 50 years, we will find it pretty primitive. In other words, most of the field remains to be discovered. That’s why it’s important to lay the foundation of trustworthy AI now,” says Fredrik Heintz, professor of artificial intelligence at LiU, and coordinator of the TAILOR project.
TAILOR is one of six research networks set up by the EU to strengthen research capacity and develop the AI of the future. The foundation of trustworthy AI is being laid by TAILOR, by drawing up a framework, guidelines and a specification of the needs of the AI research community. “TAILOR” is an abbreviation of Foundations of Trustworthy AI — integrating, learning, optimisation and reasoning.
The roadmap now presented by TAILOR is the first step on the way to standardisation, where the idea is that decision-makers and research funding bodies can gain insight into what is required to develop trustworthy AI. Fredrik Heintz believes that it is a good idea to show that many research problems must be solved before this can be achieved.
The researchers have defined three criteria for trustworthy AI: it must conform to laws and regulations, it must satisfy several ethical principles, and its implementation it must be robust and safe. Fredrik Heintz points out that these criteria pose major challenges, in particular the implementation of the ethical principles.
“Take justice, for example. Does this mean an equal distribution of resources or that all actors receive the resources needed to bring them all to the same level? We are facing major long-term questions, and it will take time before they are answered. Remember — the definition of justice has been debated by philosophers and scholars for hundreds of years,” says Fredrik Heintz.
The project will focus on large comprehensive research questions, and will attempt to find standards that all who work with AI can adopt. But Fredrik Heintz is convinced that we can only achieve this if basic research into AI is given priority.
“People often regard AI as a technology issue, but what’s really important is whether we gain societal benefit from it. If we are to obtain AI that can be trusted and that functions well in society, we must make sure that it is centred on people,” says Fredrik Heintz.
Many of the legal proposals written within the EU and its member states are written by legal specialists. But Fredrik Heintz believes that they lack expert knowledge within AI, which is a problem.
“Legislation and standards must be based on knowledge. This is where we researchers can contribute, providing information about the current forefront of research, and making well-grounded decisions possible. It’s important that experts have the opportunity to influence questions of this type,” says Fredrik Heintz.
The complete roadmap is available at: Strategic Research and Innovation Roadmap of trustworthy AI
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Across the world, many people infected with Covid-19 have been made to completely isolate from others in order to avoid passing on the infection. Some countries still recommend minimum isolation periods for as long as 10 days from when patients start to develop Covid-19 symptoms.
Professor Shingo Iwami, affiliated with Kyoto University’s Mathematical Biology Laboratory at the Institute Advanced Study of Human Biology (WPI-ASHBi) says, “Although a long time for isolation reduces the overall risk of patients passing on the infection, there will always be patients who recover early and have to accept several days of redundant isolation while no longer posing an infection risk. We would like to calculate a way to reduce this unnecessary disruption in people’s lives as well as the broader losses for the economy.”
Writing in the journal Nature Communications, an international team of scientists, led by Iwami, has reported a simulation of the potential risks and benefits of ending an individual’s isolation early using antigen tests instead of isolating patients for a fixed time. They call for more sensitive and regular antigen testing to help reduce isolation periods for patients recovering from Covid-19.
The team decided to base their model on antigen rather than PCR testing, trading sensitivity for short turn-around time, low cost, and practicality. Iwami explains that although antigen tests do have a risk of generating “false-negatives” and fail to detect individuals who could still be infectious, there are clear benefits to getting results within an hour rather than waiting a day.
Their model accounts for the sensitivity of antigen tests as well as factors like the amount of virus in a patient that makes them infectious. These are then balanced against the acceptable risk of missing unrecovered and potentially infectious patients, by letting them out of isolation early.
Using their model, the team compared different scenarios to identify the best strategy. For example, the model projects that letting a recovering patient leave isolation after 2 consecutive negative results on 2 days in a row would spend 3.9 days of redundant isolation after their recovery. But under these conditions 1 in 40 patients would continue to pose an infection risk.
More conservative approaches might increase the burden on patients by requiring more than 2 consecutive negative test results of antigen tests.
Iwami says, “The epidemic has still not completely subsided, and we are living with a lot of uncertainty with regard to new variants of the virus. Antigen tests could help, but there is also a real need for worldwide systematic guidelines that simultaneously reduce risks and burdens. We hope this simulator will help doctors and policy makers meet those demands.”
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Helping children become more ‘digitally resilient’ needs to be a collective effort if they are to learn how to “thrive online,” according to new research led by the University of East Anglia.
Digital resilience is the capability to learn how to recognise, manage and recover from online risks — such as bullying and inappropriate content — and has the potential to buffer how these experiences may impact young people’s wellbeing. Until now, research has not examined how digital resilience can be built and shown by children beyond focusing on the individual child.
This new study argues that activating digital resilience needs to be undertaken as a “collective endeavour,” involving the child, their parents/carers within home environments, youth workers, teachers, and schools at a community level, along with governments, policymakers, and internet corporations at a societal level.
It finds that digital resilience operates across these different levels, which are critical to help children learn how to recognise, manage, recover and, depending on the support available, grow following experiences of online risks.
Importantly, digital resilience across these levels and areas are not mutually exclusive but reinforce and operate on each other. As a result, say the researchers, collective responsibility must be at the heart of work in this area.
The study focused on digital resilience among pre-teens — those aged 8 to 12 years old, who are transitioning into early adolescence and seeking more independence at home, school, within society and, increasingly, through online experiences. More

We all grow old and die, but we still don’t know why. Diet, exercise and stress all effect our lifespan, but the underlying processes that drive ageing remain a mystery. Often, we measure age by counting our years since birth and yet our cells know nothing of chronological time — our organs and tissues may age more rapidly or slowly regardless of what we’d expect from counting the number of orbits we tale around the sun.
For this reason, many scientists search to develop methods to measure the “biological age” of our cells — which can be different from our chronological age. In theory, such biomarkers of ageing could provide a measure of health that could revolutionize how we practice medicine. Individuals could use a biomarker of ageing to track their biological age over time and measure the effect of diet, exercise, and drugs and predict their effects to extend lifespan or improve quality of life. Medicines could be designed and identified based on their effect on biological age. In other words, we could start to treat ageing itself.
However, no accurate and highly predictive test for biological age has been validated to date. In part, this is because we still don’t know what causes ageing and so can’t measure it. Definitive progress in the field will require validating biomarkers throughout a patient’s lifetime, an impractical feat given human life expectancy.
To understand the irreducible components of ageing, and how these can be measured and tested, researchers turn to laboratory animals. Unlike humans, the nematode C. elegans lives for an average of two weeks, making it easier to collect behavioural and lifespan data that would otherwise require centuries.
The nematode C. elegans begin adulthood vigorously exploring their environment. Over time, they slow and stop crawling, a behavioural stage known as vigorous movement cessation (VMC). VMC is a biomarker of ageing and a proxy for nematode health. Studies of genetically identical nematodes have shown it is a powerful predictor of a worm’s lifespan, but at the same time, interventions designed to alter ageing can disproportionately affect VMC in comparison to lifespan and vice versa. Researchers at the Centre for Genomic Regulation (CRG) in Barcelona seek to understand why this happens and what this means for the ageing process in humans.
A team lead by Dr. Nicholas Stroustrup, Group Leader at the CRG’s Systems Biology research programme, has developed the ‘Lifespan Machine’, a device that can follow the life and death of tens of thousands of nematodes at once. The worms live in a petri dish under the watchful eye of a scanner that monitors their entire lives. By imaging the nematodes once per hour for months, the device gathers data at unprecedented statistical resolution and scale. More