Computers Math

An artificial intelligence (AI)-based computer algorithm accurately predicted a person’s likelihood of suffering heart problems related to clogged arteries based on voice recordings alone, in a study presented at the American College of Cardiology’s 71st Annual Scientific Session.
Researchers found that people with a high voice biomarker score were 2.6 times more likely to suffer major problems associated with coronary artery disease (CAD), a buildup of plaque in the heart’s arteries, and three times more likely to show evidence of plaque buildup in medical tests compared with those who had a low score. While the technology is not yet ready for use in the clinic, the demonstration suggests voice analysis could be a powerful screening tool in identifying patients who may benefit from closer monitoring for CAD-related events. Researchers said this approach could be particularly useful in remote health care delivery and telehealth.
“Telemedicine is non-invasive, cost-effective and efficient and has become increasingly important during the pandemic,” said Jaskanwal Deep Singh Sara, MD, a cardiology fellow at Mayo Clinic and the study’s lead author. “We’re not suggesting that voice analysis technology would replace doctors or replace existing methods of health care delivery, but we think there’s a huge opportunity for voice technology to act as an adjunct to existing strategies. Providing a voice sample is very intuitive and even enjoyable for patients, and it could become a scalable means for us to enhance patient management.
The study represents the first time voice analysis has been used to predict CAD outcomes in patients who were tracked prospectively after an initial screening. Previous studies retrospectively examined voice markers associated with CAD and heart failure. Other research groups have explored the use of similar technology for a range of disorders, including Parkinson’s disease, Alzheimer’s disease and COVID-19.
For the new study, researchers recruited 108 patients who were referred for a coronary angiogram, an X-ray imaging procedure used to assess the condition of the heart’s arteries. Participants were asked to record three 30-second voice samples using the Vocalis Health smartphone application. For the first sample, participants read from a prepared text. For the second sample, they were asked to speak freely about a positive experience, and for the third, they spoke freely about a negative experience.
The Vocalis Health algorithm then analyzed participants’ voice samples. The AI-based system had been trained to analyze more than 80 features of voice recordings, such as frequency, amplitude, pitch and cadence, based on a training set of over 10,000 voice samples collected in Israel. In previous studies, researchers identified six features that were highly correlated with CAD. For the new study, researchers combined these features into a single score, expressed as a number between -1 and 1 for each individual. One-third of patients were categorized as having a high score and two-thirds had a low score.
“We can’t hear these particular features ourselves,” Sara said. “This technology is using machine learning to quantify something that isn’t easily quantifiable for us using our human brains and our human ears.”
Study participants were tracked for two years. Of those with a high voice biomarker score, 58.3% visited the hospital for chest pain or suffered acute coronary syndrome (a type of major heart problem that includes heart attacks), the study’s composite primary endpoint, compared with 30.6% of those with a low voice biomarker score. Participants with a high voice biomarker score were also more likely to have a positive stress test or be diagnosed with CAD during a subsequent angiogram (the composite secondary endpoint).
Scientists have not concluded why certain voice features seem to be indicative of CAD, but Sara said the autonomic nervous system may play a role. This part of the nervous system regulates bodily functions that are not under conscious control, which includes both the voice box and many aspects of the cardiovascular system, such as heart rate and blood pressure. Therefore, it is possible that the voice could provide clues about how the autonomic nervous system is functioning, and by extension, provide insights into cardiovascular health, Sara said.
The study was conducted with English speakers in the Midwestern U.S. using software trained on voice samples collected in Israel. Sara said more tests are needed to determine whether the approach is generalizable and scalable across languages, countries, cultures and health care settings. He added that it will also be important to address security and privacy issues before incorporating such technology into telemedicine or on-site health assessments.
“It’s definitely an exciting field, but there’s still a lot of work to be done,” Sara said. “We have to know the limitations of the data we have, and we need to conduct more studies in more diverse populations, larger trials and more prospective studies like this one.” More

Tiny biological computers made of DNA could revolutionize the way we diagnose and treat a slew of diseases, once the technology is fully fleshed out. However, a major stumbling block for these DNA-based devices, which can operate in both cells and liquid solutions, has been how short-lived they are. Just one use and the computers are spent.
Now, researchers at the National Institute of Standards and Technology (NIST) may have developed long-lived biological computers that could potentially persist inside cells. In a paper published in the journal Science Advances, the authors forgo the traditional DNA-based approach, opting instead to use the nucleic acid RNA to build computers. The results demonstrate that the RNA circuits are as dependable and versatile as their DNA-based counterparts. What’s more, living cells may be able to create these RNA circuits continuously, something that is not readily possible with DNA circuits, further positioning RNA as a promising candidate for powerful, long-lasting biological computers.
Much like the computer or smart device you are likely reading this on, biological computers can be programmed to carry out different kinds of tasks.
“The difference is, instead of coding with ones and zeroes, you write strings of A, T, C and G, which are the four chemical bases that make up DNA,” said Samuel Schaffter, NIST postdoctoral researcher and lead author of the study.
By assembling a specific sequence of bases into a strand of nucleic acid, researchers can dictate what it binds to. A strand could be engineered to attach to specific bits of DNA, RNA or some proteins associated with a disease, then trigger chemical reactions with other strands in the same circuit to process chemical information and eventually produce some sort of useful output.
That output might be a detectable signal that could aid medical diagnostics, or it could be a therapeutic drug to treat a disease. More

Reseachers have analysed samples of NdBi crystals which display interesting magnetic properties. In their experiments including measurements at BESSY II they could find evidence for so called Fermi arcs in the antiferromagnetic state of the sample at low temperatures. This observation is not yet explained by existing theoretical ideas and opens up exciting possibilities to make use of these kind of materials for innovative information technologies based on the electron spin rather than the charge.
Neodymium-Bismuth crystals belong to the wide range of materials with interesting magnetic properties. The Fermi surface which is measured in the experiments contains information on the transport properties of charge carriers in the crystal. While usually the Fermi surface consists of closed contours, disconnected sections known as Fermi arcs are very rare and can be signatures of unusual electronic states.
Unusual magnetic splittings
In a study, published now in Nature, the team presents experimental evidence for such Fermi arcs. They observed an unusual magnetic splitting in the antiferromagnetic state of the samples below a temperature of 24 Kelvin (the Néel-temperature). This splitting creates bands of opposing curvature, which changes with temperature together with the antiferromagnetic order.
These findings are very important because they are fundamentally different from previously theoretically considered and experimentally reported cases of magnetic splittings. In the case of well-known Zeeman and Rashba splittings, the curvature of the bands is always preserved. Since both splittings are important for spintronics, these new findings could lead to novel applications, especially as the focus of spintronics research is currently moving from traditional ferromagnetic to antiferromagnetic materials.
Story Source:
Materials provided by Helmholtz-Zentrum Berlin für Materialien und Energie. Note: Content may be edited for style and length. More

Researchers have developed a new high-purity single-photon source that can operate at room temperature. The source is an important step toward practical applications of quantum technology, such as highly secure communication based on quantum key distribution (QKD).
“We developed an on-demand way to generate photons with high purity in a scalable and portable system that operates at room temperature,” said Helen Zeng, a member of the research team from the University of Technology Sydney in Australia. “Our single-photon source could advance the development of practical QKD systems and can be integrated into a variety of real-world quantum photonic applications.”
In the Optica Publishing Group journal Optics Letters, Zeng and colleagues from Australia’s University of New South Wales and Macquarie University describe their new single-photon source and show that it can produce over ten million single photons per second at room temperature. They also incorporated the single-photon source into a fully portable device that can perform QKD.
The new single-photon source uniquely combines a 2D material called hexagonal boron nitride with an optical component known as a hemispherical solid immersion lens, which increases the source’s efficiency by a factor of six.
Single photons at room temperature
QKD offers impenetrable encryption for data communication by using the quantum properties of light to generate secure random keys for encrypting and decrypting data. QKD systems require robust and bright sources that emit light as a string of single photons. However, most of today’s single-photon sources don’t perform well unless operated at cryogenic temperatures hundreds of degrees below zero, which limits their practicality. More

Atomic clocks are the best sensors humankind has ever built. Today, they can be found in national standards institutes or satellites of navigation systems. Scientists all over the world are working to further optimize the precision of these clocks. Now, a research group led by Peter Zoller, a theorist from Innsbruck, Austria, has developed a new concept that can be used to operate sensors with even greater precision irrespective of which technical platform is used to make the sensor. “We answer the question of how precise a sensor can be with existing control capabilities, and give a recipe for how this can be achieved,” explain Denis Vasilyev and Raphael Kaubrügger from Peter Zoller’s group at the Institute of Quantum Optics and Quantum Information at the Austrian Academy of Sciences in Innsbruck.
For this purpose, the physicists use a method from quantum information processing: variational quantum algorithms describe a circuit of quantum gates that depends on free parameters. Through optimization routines, the sensor autonomously finds the best settings for an optimal result. “We applied this technique to a problem from metrology — the science of measurement,” Vasilyev and Kaubrügger explain. “This is exciting because historically advances in atomic physics were motivated by metrology, and in turn quantum information processing emerged from that. So, we’ve come full circle here,” Peter Zoller enthuses. With the new approach, scientists can optimize quantum sensors to the point where they achieve the best possible precision technically permissible.
Better measurements with little extra effort
For some time, it has been understood that atomic clocks could run even more accurately by exploiting quantum mechanical entanglement. However, there has been a lack of methods to realize robust entanglement for such applications. The Innsbruck physicists are now using tailor-made entanglement that is precisely tuned to real-world requirements. With their method, they generate exactly the combination consisting of quantum state and measurements that is optimal for each individual quantum sensor. This allows the precision of the sensor to be brought close to the optimum possible according to the laws of nature, with only a slight increase in overhead. “In the development of quantum computers, we have learned to create tailored entangled states,” says Christian Marciniak from the Department of Experimental Physics at the University of Innsbruck. “We are now using this knowledge to build better sensors.”
Demonstrating quantum advantage with sensors
This theoretical concept was now implemented in practice for the first time at the University of Innsbruck, as the research group led by Thomas Monz and Rainer Blatt now reported in Nature. The physicists performed frequency measurements based on variational quantum calculations on their ion trap quantum computer. Because the interactions used in linear ion traps are still relatively easy to simulate on classical computers, the theory colleagues were able to check the necessary parameters on a supercomputer at the University of Innsbruck. Although the experimental setup is by no means perfect, the results agree surprisingly well with the theoretically predicted values. Since such simulations are not feasible for all sensors, the scientists demonstrated a second approach: They used methods to automatically optimize the parameters without prior knowledge. “Similar to machine learning, the programmable quantum computer finds its optimal mode autonomously as a high-precision sensor,” says experimental physicist Thomas Feldker, describing the underlying mechanism.
“Our concept makes it possible to demonstrate the advantage of quantum technologies over classical computers on a problem of practical relevance,” emphasizes Peter Zoller. “We have demonstrated a crucial component of quantum-enhanced atomic clocks with our variational Ramsey interferometry. Running this in a dedicated atomic clock is the next step. What has so far only been shown for calculations of questionable practical relevance could now be demonstrated with a programmable quantum sensor in the near future — quantum advantage.”
The research was financially supported by the Austrian Science Fund FWF, the Research Promotion Agency FFG, the European Union within the framework of the Quantum Flagship and the Federation of Austrian Industries Tyrol, among others.
Story Source:
Materials provided by University of Innsbruck. Note: Content may be edited for style and length. More

Lay some graphene down on a wavy surface, and you’ll get a guide to one possible future of two-dimensional electronics.
Rice University scientists put forth the idea that growing atom-thick graphene on a gently textured surface creates peaks and valleys in the sheets that turn them into “pseudo-electromagnetic” devices.
The channels create their own minute but detectable magnetic fields. According to a study by materials theorist Boris Yakobson, alumnus Henry Yu and research scientist Alex Kutana at Rice’s George R. Brown School of Engineering, these could facilitate nanoscale optical devices like converging lenses or collimators.
Their study appears in the American Chemical Society’s Nano Letters.
They also promise a way to achieve a Hall effect — a voltage difference across the strongly conducting graphene — that could facilitate valleytronics applications that manipulate how electrons are trapped in “valleys” in an electronic band structure.
Valleytronics are related to spintronics, in which a device’s memory bits are defined by an electron’s quantum spin state. But in valleytronics, electrons have degrees of freedom in the multiple momentum states (or valleys) they occupy. These can also be read as bits.
This is all possible because graphene, while it may be one of the strongest known structures, is pliable enough as it adheres to a surface during chemical vapor deposition.
“Substrate sculpting imparts deformation, which in turn alters the material electronic structure and changes its optical response or electric conductivity,” said Yu, now a postdoctoral researcher at Lawrence Livermore National Laboratory. “For sharper substrate features beyond the pliability of the material, one can engineer defect placements in the materials, which creates even more drastic changes in material properties.”
Yakobson compared the process to depositing a sheet of graphene on an egg crate. The bumps in the crate deform the graphene, stressing it in a way that creates an electromagnetic field even without electrical or magnetic input.
“The endless designs of substrate shapes allow for countless optical devices that can be created, making possible 2D electron optics,” Yakobson said. “This technology is a precise and efficient way of transmitting material carriers in 2D electronic devices, compared to traditional methods.”
Yakobson is the Karl F. Hasselmann Professor of Materials Science and NanoEngineering and a professor of chemistry.
The Office of Naval Research (N00014-18-1-2182) and the Army Research Office (W911NF-16-1-0255) supported the research.
Story Source:
Materials provided by Rice University. Original written by Mike Williams. Note: Content may be edited for style and length. More

Investigators from Cedars-Sinai have created an artificial intelligence-enabled tool that may make it easier to predict if a person will have a heart attack.
The tool, described in The Lancet Digital Health, accurately predicted which patients would experience a heart attack in five years based on the amount and composition of plaque in arteries that supply blood to the heart.
Plaque buildup can cause arteries to narrow, which makes it difficult for blood to get to the heart, increasing the likelihood of a heart attack. A medical test called a coronary computed tomography angiography (CTA) takes 3D images of the heart and arteries and can give doctors an estimate of how much a patient’s arteries have narrowed. Until now, however, there has not been a simple, automated and rapid way to measure the plaque visible in the CTA images.
“Coronary plaque is often not measured because there is not a fully automated way to do it,” said Damini Dey, PhD, director of the quantitative image analysis lab in the Biomedical Imaging Research Institute at Cedars-Sinai and senior author of the study. “When it is measured, it takes an expert at least 25 to 30 minutes, but now we can use this program to quantify plaque from CTA images in five to six seconds.”
Dey and colleagues analyzed CTA images from 1,196 people who underwent a coronary CTA at 11 sites in Australia, Germany, Japan, Scotland and the United States. The investigators trained the AI algorithm to measure plaque by having it learn from coronary CTA images, from 921 people, that already had been analyzed by trained doctors.
The algorithm works by first outlining the coronary arteries in 3D images, then identifying the blood and plaque deposits within the coronary arteries. Investigators found the tool’s measurements corresponded with plaque amounts seen in coronary CTAs. They also matched results with images taken by two invasive tests considered to be highly accurate in assessing coronary artery plaque and narrowing: intravascular ultrasound and catheter-based coronary angiography.
Finally, the investigators discovered that measurements made by the AI algorithm from CTA images accurately predicted heart attack risk within five years for 1,611 people who were part of a multicenter trial called the SCOT-HEART trial.
“More studies are needed, but it’s possible we may be able to predict if and how soon a person is likely to have a heart attack based on the amount and composition of the plaque imaged with this standard test,” said Dey, who is also professor of Biomedical Sciences at Cedars-Sinai.
Dey and colleagues are continuing to study how well their AI algorithm quantifies plaque deposits in patients who undergo coronary CTA.
Funding: The study was funded by the National Heart, Lung, and Blood Institute under award number 1R01HL148787-01A1.
Story Source:
Materials provided by Cedars-Sinai Medical Center. Note: Content may be edited for style and length. More

In a new study, North Carolina State University researchers found a way to prevent electrical malfunctions in yarns designed to store electrical energy. Ultimately, the findings could help advance the development of “smart textiles” that would capture energy from the wearer’s movements and power sensors and wearable electronics.
The researchers reported in npj Flexible Electronics that they were able to prevent short-circuiting in yarns that act as supercapacitors — which are electrical devices that store energy — by wrapping the yarns with an insulating thread. They also tested the strength and durability of the yarns to make sure they could still work after going through knitting and weaving processes.
“A supercapacitor functions like a battery, but in this case, we’re working on a flexible battery shaped as a textile yarn that you could weave or knit into your T-shirt or sweater,” said Wei Gao, associate professor of textile engineering, chemistry and science and a University Faculty Scholar at NC State. “In this study, we have woven this yarn into a piece of fabric so that it can store electrical energy, and eventually we want to use it to power whatever electronic devices you need, whether it be a sensor, a light or even a cell phone.”
While research into these so-called “yarn-shaped supercapacitors” is promising, researchers say developers face a consistent problem with their design: the yarn-shaped supercapacitors are more likely to short circuit as their length increases. Short-circuiting is when the electric current flows through an unintended path. It is a safety concern because a short circuit can result in a burst of heat energy or even a fire.
“Everybody is trying to make smart electronics that can be incorporated into cloth or fabric,” Gao said. “What we found is if you try to make a supercapacitor yarn longer than 8 inches, it’s pretty easy for this device to short-circuit. It’s pretty dangerous, and it’s something nobody wants to encounter when wearing a smart suit.”
To solve that problem, the researchers tested what would happen when they wrapped the super-capacitor yarn electrodes with insulating threads. The idea was that the threads would act as a physical barrier, keeping the opposite electrodes from contacting each other and preventing short-circuiting. They tested their device’s performance by connecting the electrodes to a power source and recording the device’s current response. They also tested how well the yarns were able to hold a charge. They found that the yarns kept 90% of the initial energy after charging and discharging them 10,000 times. More