Computers Math

Researchers at the National University of Singapore (NUS) have developed a novel aero-elastic pressure sensor, called ‘eAir’. This technology can be applied to minimally-invasive surgeries and implantable sensors by directly addressing the challenges associated with existing pressure sensors.
The eAir sensor promises increased precision and reliability across medical applications. It can potentially transform laparoscopic surgeries by enabling tactile feedback for surgeons, allowing more precise manipulation of patient tissues. In addition, the sensor can improve patient experiences by offering a less invasive means of monitoring intracranial pressure (ICP), a key health metric for individuals with neurological conditions.
Led by Associate Professor Benjamin TEE from the NUS College of Design and Engineering and NUS Institute for Health Innovation & Technology, the research team’s findings were recently published in scientific journal Nature Materials on 17 August 2023.
From lotus leaf to laboratory: Harnessing nature’s design
Conventional pressure sensors frequently struggle with accuracy. They have trouble delivering consistent readings, often returning varying results when the same pressure is applied repeatedly and can overlook subtle changes in pressure — all of which can lead to significant errors. They are also typically made from stiff and mechanically inflexible materials.
To address these challenges in pressure sensing, the NUS team drew inspiration from a phenomenon known as the ‘lotus leaf effect’ — a unique natural phenomenon where water droplets effortlessly roll off the leaf’s surface, made possible by its minuscule, water-repelling structures. Mimicking this effect, the team has engineered a pressure sensor designed to significantly improve the sensing performance.
“The sensor, akin to a miniature ‘capacity meter’, can detect minute pressure changes — mirroring the sensitivity of a lotus leaf to the extremely light touch of a water droplet,” explained Assoc Prof Tee. More

Environmental regulators and other organizations should do more scientific experimentation to inform natural resource policy, according to an international group of economists that includes University of Wyoming researchers.
In a new paper in the  journal Science, the economists say more frequent use of up-front experiments would result in more effective environmental policymaking in areas ranging from pollution control to timber harvesting across the world.
“Although formal experimentation is a cornerstone of science and is increasingly embedded in nonenvironmental social programs, it is virtually absent in environmental programs,” the researchers wrote. “Strengthening the culture of experimentation in the environmental community will require changes in norms and incentives.”
The paper acknowledges that scientists and practitioners can legitimately argue about how much time and effort should be given to experiments in environmental policy, but it contends that the current allocation of roughly zero percent is suboptimal.
The paper was produced by The Teton Group, an initiative led by Professor Todd Cherry, the John S. Bugas Chair in UW’s Department of Economics. The prominent group of economists meets every fall in Wyoming to discuss critical ideas that impact environmental policy and economic development. Members include colleagues from UW and scholars in behavioral environmental policy from Carnegie Mellon University, Johns Hopkins University, Purdue University, the University of Texas-Austin, the University of Wisconsin-Madison and several key European universities. The group of UW economists include Todd Cherry, Jacob Hochard, Stephen Newbold, Jason Shogren, Linda Thunström and Klaas van ‘t veld.
“Guesswork is expensive, so we need to apply tools that reduce uncertainty about what works and what doesn’t,” Cherry says. “Lessons learned can improve current and future policy.”
According to the new paper, environmental scientists and practitioners typically rely on field experience, case studies and retrospective evaluations of programs that were not designed to generate evidence about cause and effect. The result can be ineffective or even counterproductive programs. More

Osaka Metropolitan University scientists have developed an AI model that accurately estimates a patient’s age, using chest radiographs of healthy individuals collected from multiple facilities. Furthermore, they found a positive relationship between differences in the AI-estimated and chronological ages and a variety of chronic diseases, such as hypertension, hyperuricemia, and chronic obstructive pulmonary disease. In the future, it is expected that AI biomarkers will be developed to predict life expectancy, estimate the severity of chronic diseases, and forecast surgery-related risks.
What if “looking your age” refers not to your face, but to your chest? Osaka Metropolitan University scientists have developed an advanced artificial intelligence (AI) model that utilizes chest radiographs to accurately estimate a patient’s chronological age. More importantly, when there is a disparity, it can signal a correlation with chronic disease. These findings mark a leap in medical imaging, paving the way for improved early disease detection and intervention. The results are set to be published in The Lancet Healthy Longevity.
The research team, led by graduate student Yasuhito Mitsuyama and Dr. Daiju Ueda from the Department of Diagnostic and Interventional Radiology at the Graduate School of Medicine, Osaka Metropolitan University, first constructed a deep learning-based AI model to estimate age from chest radiographs of healthy individuals. They then applied the model to radiographs of patients with known diseases to analyze the relationship between AI-estimated age and each disease. Given that AI trained on a single dataset is prone to overfitting, the researchers collected data from multiple institutions.
For the development, training, internal and external testing of the AI model for age estimation, a total of 67,099 chest radiographs were obtained between 2008 and 2021 from 36,051 healthy individuals who underwent health check-ups at three facilities. The developed model showed a correlation coefficient of 0.95 between the AI-estimated age and chronological age. Generally, a correlation coefficient of 0.9 or higher is considered to be very strong.
To validate the usefulness of AI-estimated age using chest radiographs as a biomarker, an additional 34,197 chest radiographs were compiled from 34,197 patients with known diseases from two other institutions. The results revealed that the difference between AI-estimated age and the patient’s chronological age was positively correlated with a variety of chronic diseases, such as hypertension, hyperuricemia, and chronic obstructive pulmonary disease. In other words, the higher the AI-estimated age compared to the chronological age, the more likely individuals were to have these diseases.
“Chronological age is one of the most critical factors in medicine,” stated Mr. Mitsuyama. “Our results suggest that chest radiography-based apparent age may accurately reflect health conditions beyond chronological age. We aim to further develop this research and apply it to estimate the severity of chronic diseases, to predict life expectancy, and to forecast possible surgical complications.” More

Trinity’s quantum physicists in collaboration with IBM Dublin have successfully simulated super diffusion in a system of interacting quantum particles on a quantum computer.
This is the first step in doing highly challenging quantum transport calculations on quantum hardware and, as the hardware improves over time, such work promises to shed new light in condensed matter physics and materials science.
The work is one of the first outputs of the TCD-IBM predoctoral scholarship programme which was recently established where IBM hires PhD students as employees while being co-supervised at Trinity. The paper was published recently in leading Nature journal NPJ Quantum Information.
IBM is a global leader in the exciting field of quantum computation. The early stage quantum computer used in this study consists of 27 superconducting qubits (qubits are the building blocks of quantum logic) and is physically located in IBMs lab in Yorktown Heights in New York and programmed remotely from Dublin.
Quantum computing is currently one of the most exciting technologies and is expected to be edging closer towards commercial applications in the next decade. Commercial applications aside there are fascinating fundamental questions which quantum computers can help with. The team at Trinity and IBM Dublin tackled one such question concerning quantum simulation.
Explaining the significance of the work and the idea of quantum simulation in general, Trinity’s Professor John Goold, Director of the newly established Trinity Quantum Alliance, who led the research, explains:
“Generally speaking the problem of simulating the dynamics of a complex quantum system with many interacting constituents is a formidable challenge for conventional computers. Consider the 27 qubits on this particular device. In quantum mechanics the state of such a system is described mathematically by an object called a wave function. In order to use a standard computer to describe this object you require a huge number of coefficients to be stored in memory and the demands scale exponentially with the number of qubits; roughly 134 million coefficients, in the case of this simulation. More

A new study led by Vinod M. Menon and his group at the City College of New York shows that trapping light inside magnetic materials may dramatically enhance their intrinsic properties. Strong optical responses of magnets are important for the development of magnetic lasers and magneto-optical memory devices, as well as for emerging quantum transduction applications.
In their new article in Nature, Menon and his team report the properties of a layered magnet that hosts strongly bound excitons — quasiparticles with particularly strong optical interactions. Because of that, the material is capable of trapping light — all by itself. As their experiments show, the optical responses of this material to magnetic phenomena are orders of magnitude stronger than those in typical magnets. “Since the light bounces back and forth inside the magnet, interactions are genuinely enhanced,” said Dr. Florian Dirnberger, the lead-author of the study. “To give an example, when we apply an external magnetic field the near-infrared reflection of light is altered so much, the material basically changes its color. That’s a pretty strong magneto-optic response.”
“Ordinarily, light does not respond so strongly to magnetism,” said Menon. “This is why technological applications based on magneto-optic effects often require the implementation of sensitive optical detection schemes.”
On how the advances can benefit ordinary people, study co-author Jiamin Quan said: “Technological applications of magnetic materials today are mostly related to magneto-electric phenomena. Given such strong interactions between magnetism and light, we can now hope to one day create magnetic lasers and may reconsider old concepts of optically controlled magnetic memory.” Rezlind Bushati, a graduate student in the Menon group, also contributed to the experimental work.
The study conducted in close collaboration with Andrea Alù and his group at CUNY Advanced Science Research Center is the result of a major international collaboration. Experiments conducted at CCNY and ASRC were complemented by measurements taken at the University of Washington in the group of Prof. Xiaodong Xu by Dr. Geoffrey Diederich. Theoretical support was provided by Dr. Akashdeep Kamra and Prof. Francisco J. Garcia-Vidal from the Universidad Autónoma de Madrid and Dr. Matthias Florian from the University of Michigan. The materials were grown by Prof. Zdenek Sofer and Kseniia Mosina at the UCT Prague and the project was further supported by Dr. Julian Klein at MIT. The work at CCNY was supported through the US Air Force Office of Scientific Research, the National Science Foundation (NSF) — Division of Materials Research, the NSF CREST IDEALS center, DARPA and the German Research Foundation. More

Research is underway around the world to find alternatives to our current electronic computing technology, as great, electron-based systems have limitations. A new way of transmitting information is emerging from the field of magnonics: instead of electron exchange, the waves generated in magnetic media could be used for transmission, but magnonics-based computing has been (too) slow to date. Scientists at the University of Vienna have now discovered a significant new method: When the intensity is increased, the spin waves become shorter and faster — another step towards magnon computing. The results were published in the journal Science Advances.
Magnonics is a relatively new field of research in magnetism. Spin waves play a central role: A local disturbance in the magnetic order of a magnet can propagate as waves through a material. These waves are called spin waves, and the associated quasiparticles are called magnons. They carry information in the form of angular momentum pulses. Because of this property, they can be used as low-power data carriers in smaller and more energy-efficient computers of the future. The main challenge in magnonics is wavelength. The larger it is, the slower magnon-based data processing units are. Until now, the wavelength could only be shortened with very complex hybrid structures or a synchrotron. The research group “Nanomagnetism and Magnononics” at the University of Vienna, together with colleagues from Germany, the Czech Republic, Ukraine and China, has developed a simpler alternative. First author Qi Wang made the crucial observation after months of work in the Brillouin light scattering spectroscopy laboratory at the University of Vienna’s Faculty of Physics: if you increase the intensity, the spin waves become shorter and faster — a breakthrough method for magnonic computing.
Co-author of the study and leader of the Vienna NanoMag team, Andrii Chumak, explains the discovery with a metaphor: “It is helpful to imagine the method with light. If you change the wavelength of light, its color changes. But if you change the intensity, only the luminosity changes. In this case, we found a way to change the color by changing the intensity of the spin waves. This phenomenon allowed us to excite much shorter and much better spin waves,” Chumak said.
The current wavelength found with this system is about 200 nanometers. According to numerical simulations, it would be possible to excite even smaller wavelengths, but at this stage it is very difficult to excite or measure these orders of magnitude.
The amplitudes of the spin waves are also crucial for future magnetic integrated circuits. The discovered system exhibits a self-locking nonlinear shift, which means that the amplitude of the excited spin waves is constant. This property is very relevant for integrated circuits, as it allows different magnetic elements to work together with the same amplitude. This, in turn, is fundamental to the construction of more complex systems and to the realization of the distant goal of a magnon-based computer. The ultimate goal, a fully functional magnon computer, has not yet been achieved. Nevertheless, this solid milestone brings researchers a good deal closer to their goal. More

Researchers have found a way to control the interaction of light and quantum ‘spin’ in organic semiconductors, that works even at room temperature.
Spin is the term for the intrinsic angular momentum of electrons, which is referred to as up or down. Using the up/down spin states of electrons instead of the 0 and 1 in conventional computer logic could transform the way in which computers process information. And sensors based on quantum principles could vastly improve our abilities to measure and study the world around us.
An international team of researchers, led by the University of Cambridge, has found a way to use particles of light as a ‘switch’ that can connect and control the spin of electrons, making them behave like tiny magnets that could be used for quantum applications.
The researchers designed modular molecular units connected by tiny ‘bridges’. Shining a light on these bridges allowed electrons on opposite ends of the structure to connect to each other by aligning their spin states. Even after the bridge was removed, the electrons stayed connected through their aligned spins.
This level of control over quantum properties can normally only be achieved at ultra-low temperatures. However, the Cambridge-led team has been able to control the quantum behaviour of these materials at room temperature, which opens up a new world of potential quantum applications by reliably coupling spins to photons. The results are reported in the journal Nature.
Almost all types of quantum technology — based on the strange behaviour of particles at the subatomic level — involve spin. As they move, electrons usually form stable pairs, with one electron spin up and one spin down. However, it is possible to make molecules with unpaired electrons, called radicals. Most radicals are very reactive, but with careful design of the molecule, they can be made chemically stable.
“These unpaired spins change the rules for what happens when a photon is absorbed and electrons are moved up to a higher energy level,” said first author Sebastian Gorgon, from Cambridge’s Cavendish Laboratory. “We’ve been working with systems where there is one net spin, which makes them good for light emission and making LEDs.”
Gorgon is a member of Professor Sir Richard Friend’s research group, where they have been studying radicals in organic semiconductors for light generation, and identified a stable and bright family of materials a few years ago. These materials can beat the best conventional OLEDs for red light generation. More

Artificial neural networks, ubiquitous machine-learning models that can be trained to complete many tasks, are so called because their architecture is inspired by the way biological neurons process information in the human brain.
About six years ago, scientists discovered a new type of more powerful neural network model known as a transformer. These models can achieve unprecedented performance, such as by generating text from prompts with near-human-like accuracy. A transformer underlies AI systems such as ChatGPT and Bard, for example. While incredibly effective, transformers are also mysterious: Unlike with other brain-inspired neural network models, it hasn’t been clear how to build them using biological components.
Now, researchers from MIT, the MIT-IBM Watson AI Lab, and Harvard Medical School have produced a hypothesis that may explain how a transformer could be built using biological elements in the brain. They suggest that a biological network composed of neurons and other brain cells called astrocytes could perform the same core computation as a transformer.
Recent research has shown that astrocytes, non-neuronal cells that are abundant in the brain, communicate with neurons and play a role in some physiological processes, like regulating blood flow. But scientists still lack a clear understanding of what these cells do computationally.
With the new study, published this week in open-access format in the Proceedings of the National Academy of Sciences, the researchers explored the role astrocytes play in the brain from a computational perspective, and crafted a mathematical model that shows how they could be used, along with neurons, to build a biologically plausible transformer.
Their hypothesis provides insights that could spark future neuroscience research into how the human brain works. At the same time, it could help machine-learning researchers explain why transformers are so successful across a diverse set of complex tasks.
“The brain is far superior to even the best artificial neural networks that we have developed, but we don’t really know exactly how the brain works. There is scientific value in thinking about connections between biological hardware and large-scale artificial intelligence networks. This is neuroscience for AI and AI for neuroscience,” says Dmitry Krotov, a research staff member at the MIT-IBM Watson AI Lab and senior author of the research paper. More