Computers Math

Researchers have developed a new mechanical model that simulates how whiskers bend within a follicle in response to an external force, paving the way toward better understanding of how whiskers contribute to mammals’ sense of touch. Yifu Luo and Mitra Hartmann of Northwestern University and colleagues present these findings in the open-access journal PLOS Computational Biology.
With the exception of some primates, most mammals use whiskers to explore their environment through the sense of touch. Whiskers have no sensors along their length, but when an external force bends a whisker, that deformation extends into the follicle at the base of the whisker, where the whisker pushes or pulls on sensor cells, triggering touch signals in the nervous system.
Few previous studies have examined how whiskers deform within follicles in order to impinge on the sensor cells — mechanoreceptors — inside. To better understand this process, Luo and colleagues drew on data from experimental studies of whisker follicles to create the first mechanical model capable of simulating whisker deformation within follicles.
The simulations suggest that whisker deformation within follicles most likely occurs in an “S” shape, although future experimental data may show that the deformation is “C” shaped. The researchers demonstrate that these shape estimates can be used to predict how whiskers push and pull on different kinds of mechanoreceptors located in different parts of the follicle, influencing touch signals sent to the brain.
The new model applies to both passive touch and active “whisking,” when an animal uses muscles to move its whiskers. The simulations suggest that, during active whisking, the tactile sensitivity of the whisker system is enhanced by increased blood pressure in the follicle and by increased stiffness of follicular muscle and tissue structures.
“It is exciting to use simulations, constrained by anatomical observations, to gain insights into biological processes that cannot be directly measured experimentally,” Hartmann says. “The work also underscores just how important mechanics are to understanding the sensory signals that the brain has evolved to process.”
Future research will be needed to refine the model, both computationally and by incorporating new experimental data.
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Brain-computer interfaces (BCIs) are an emerging assistive technology, enabling people with paralysis to type on computer screens or manipulate robotic prostheses just by thinking about moving their own bodies. For years, investigational BCIs used in clinical trials have required cables to connect the sensing array in the brain to computers that decode the signals and use them to drive external devices.
Now, for the first time, BrainGate clinical trial participants with tetraplegia have demonstrated use of an intracortical wireless BCI with an external wireless transmitter. The system is capable of transmitting brain signals at single-neuron resolution and in full broadband fidelity without physically tethering the user to a decoding system. The traditional cables are replaced by a small transmitter about 2 inches in its largest dimension and weighing a little over 1.5 ounces. The unit sits on top of a user’s head and connects to an electrode array within the brain’s motor cortex using the same port used by wired systems.
For a study published in IEEE Transactions on Biomedical Engineering, two clinical trial participants with paralysis used the BrainGate system with a wireless transmitter to point, click and type on a standard tablet computer. The study showed that the wireless system transmitted signals with virtually the same fidelity as wired systems, and participants achieved similar point-and-click accuracy and typing speeds.
“We’ve demonstrated that this wireless system is functionally equivalent to the wired systems that have been the gold standard in BCI performance for years,” said John Simeral, an assistant professor of engineering (research) at Brown University, a member of the BrainGate research consortium and the study’s lead author. “The signals are recorded and transmitted with appropriately similar fidelity, which means we can use the same decoding algorithms we used with wired equipment. The only difference is that people no longer need to be physically tethered to our equipment, which opens up new possibilities in terms of how the system can be used.”
The researchers say the study represents an early but important step toward a major objective in BCI research: a fully implantable intracortical system that aids in restoring independence for people who have lost the ability to move. While wireless devices with lower bandwidth have been reported previously, this is the first device to transmit the full spectrum of signals recorded by an intracortical sensor. That high-broadband wireless signal enables clinical research and basic human neuroscience that is much more difficult to perform with wired BCIs.
The new study demonstrated some of those new possibilities. The trial participants — a 35-year-old man and a 63-year-old man, both paralyzed by spinal cord injuries — were able to use the system in their homes, as opposed to the lab setting where most BCI research takes place. Unencumbered by cables, the participants were able to use the BCI continuously for up to 24 hours, giving the researchers long-duration data including while participants slept. More

When it comes to powering mobile robots, batteries present a problematic paradox: the more energy they contain, the more they weigh, and thus the more energy the robot needs to move. Energy harvesters, like solar panels, might work for some applications, but they don’t deliver power quickly or consistently enough for sustained travel.
James Pikul, assistant professor in Penn Engineering’s Department of Mechanical Engineering and Applied Mechanics, is developing robot-powering technology that has the best of both worlds. His environmentally controlled voltage source, or ECVS, works like a battery, in that the energy is produced by repeatedly breaking and forming chemical bonds, but it escapes the weight paradox by finding those chemical bonds in the robot’s environment, like a harvester. While in contact with a metal surface, an ECVS unit catalyzes an oxidation reaction with the surrounding air, powering the robot with the freed electrons.
Pikul’s approach was inspired by how animals power themselves through foraging for chemical bonds in the form of food. And like a simple organism, these ECVS-powered robots are now capable of searching for their own food sources despite lacking a “brain.”
In a new study published as an Editor’s Choice article in Advanced Intelligent Systems, Pikul, along with lab members Min Wang and Yue Gao, demonstrate a wheeled robot that can navigate its environment without a computer. By having the left and right wheels of the robot powered by different ECVS units, they show a rudimentary form of navigation and foraging, where the robot will automatically steer toward metallic surfaces it can “eat.”
Their study also outlines more complicated behavior that can be achieved without a central processor. With different spatial and sequential arrangements of ECVS units, a robot can perform a variety of logical operations based on the presence or absence of its food source.
“Bacteria are able to autonomously navigate toward nutrients through a process called chemotaxis, where they sense and respond to changes in chemical concentrations,” Pikul says. “Small robots have similar constraints to microorganisms, since they can’t carry big batteries or complicated computers, so we wanted to explore how our ECVS technology could replicate that kind of behavior.”
In the researchers’ experiments, they placed their robot on aluminum surfaces capable of powering its ECVS units. By adding “hazards” that would prevent the robot from making contact with the metal, they showed how ECVS units could both get the robot moving and navigate it toward more energy-rich sources. More

A thermos bottle has the task of preserving the temperature — but sometimes you want to achieve the opposite: Computer chips generate heat that must be dissipated as quickly as possible so that the chip is not destroyed. This requires special materials with particularly good heat conduction properties.
In collaboration with groups from China and the United States, a research team from TU Wien therefore set out to find the optimal heat conductor. They finally found what they were looking for in a very specific form of tantalum nitride — no other known metallic material has a higher thermal conductivity. In order to be able to identify this record-breaking material, they first had to analyse which processes play a role in heat conduction in such materials at the atomic level. The results have now been published in the scientific journal Physical Review Letters.
Electrons and lattice vibrations
“Basically, there are two mechanisms by which heat propagates in a material,” explains Prof. Georg Madsen from the Institute of Materials Chemistry at TU Wien. “Firstly, through the electrons that travel through the material, taking energy with them. This is the main mechanism in good electrical conductors. And secondly through the phonons, which are collective lattice vibrations in the material.” The atoms move, causing other atoms to wobble. At higher temperatures, heat conduction through propagation of these vibrations is usually the decisive effect.
But neither the electrons nor the lattice vibrations can propagate completely unhindered through the material. There are various processes that slow down this propagation of thermal energy. Electrons and lattice vibrations can interact with each other, they can scatter, they can be stopped by irregularities in the material.
In some cases, heat conduction can even be dramatically limited by the fact that different isotopes of an element are built into the material — i.e. similar atoms with different numbers of neutrons. In that case, the atoms do not have exactly the same mass, and this affects the collective vibrational behaviour of the atoms in the material. More

Last year, a team of biologists and computer scientists from Tufts University and the University of Vermont (UVM) created novel, tiny self-healing biological machines from frog cells called “Xenobots” that could move around, push a payload, and even exhibit collective behavior in the presence of a swarm of other Xenobots.
Get ready for Xenobots 2.0.
The same team has now created life forms that self-assemble a body from single cells, do not require muscle cells to move, and even demonstrate the capability of recordable memory. The new generation Xenobots also move faster, navigate different environments, and have longer lifespans than the first edition, and they still have the ability to work together in groups and heal themselves if damaged. The results of the new research were published today in Science Robotics.
Compared to Xenobots 1.0, in which the millimeter-sized automatons were constructed in a “top down” approach by manual placement of tissue and surgical shaping of frog skin and cardiac cells to produce motion, the next version of Xenobots takes a “bottom up” approach. The biologists at Tufts took stem cells from embryos of the African frog Xenopus laevis (hence the name “Xenobots”) and allowed them to self-assemble and grow into spheroids, where some of the cells after a few days differentiated to produce cilia — tiny hair-like projections that move back and forth or rotate in a specific way. Instead of using manually sculpted cardiac cells whose natural rhythmic contractions allowed the original Xenobots to scuttle around, cilia give the new spheroidal bots “legs” to move them rapidly across a surface. In a frog, or human for that matter, cilia would normally be found on mucous surfaces, like in the lungs, to help push out pathogens and other foreign material. On the Xenobots, they are repurposed to provide rapid locomotion.
“We are witnessing the remarkable plasticity of cellular collectives, which build a rudimentary new ‘body’ that is quite distinct from their default — in this case, a frog — despite having a completely normal genome,” said Michael Levin, Distinguished Professor of Biology and director of the Allen Discovery Center at Tufts University, and corresponding author of the study. “In a frog embryo, cells cooperate to create a tadpole. Here, removed from that context, we see that cells can re-purpose their genetically encoded hardware, like cilia, for new functions such as locomotion. It is amazing that cells can spontaneously take on new roles and create new body plans and behaviors without long periods of evolutionary selection for those features.”
“In a way, the Xenobots are constructed much like a traditional robot. Only we use cells and tissues rather than artificial components to build the shape and create predictable behavior.” said senior scientist Doug Blackiston, who co-first authored the study with research technician Emma Lederer. “On the biology end, this approach is helping us understand how cells communicate as they interact with one another during development, and how we might better control those interactions.”
While the Tufts scientists created the physical organisms, scientists at UVM were busy running computer simulations that modeled different shapes of the Xenobots to see if they might exhibit different behaviors, both individually and in groups. Using the Deep Green supercomputer cluster at UVM’s Vermont Advanced Computing Core, the team, led by computer scientists and robotics experts Josh Bongard and under hundreds of thousands of random environmental conditions using an evolutionary algorithm. These simulations were used to identify Xenobots most able to work together in swarms to gather large piles of debris in a field of particles. More

The qubit is the building block of quantum computing, analogous to the bit in classical computers. To perform error-free calculations, quantum computers of the future are likely to need at least millions of qubits. The latest study, published in the journal PRX Quantum, suggests that these computers could be made with industrial-grade silicon chips using existing manufacturing processes, instead of adopting new manufacturing processes or even newly discovered particles.
For the study, researchers were able to isolate and measure the quantum state of a single electron (the qubit) in a silicon transistor manufactured using a ‘CMOS’ technology similar to that used to make chips in computer processors.
Furthermore, the spin of the electron was found to remain stable for a period of up to nine seconds. The next step is to use a similar manufacturing technology to show how an array of qubits can interact to perform quantum logic operations.
Professor John Morton (London Centre for Nanotechnology at UCL), co-founder of Quantum Motion, said: “We’re hacking the process of creating qubits, so the same kind of technology that makes the chip in a smartphone can be used to build quantum computers.
“It has taken 70 years for transistor development to reach where we are today in computing and we can’t spend another 70 years trying to invent new manufacturing processes to build quantum computers. We need millions of qubits and an ultra-scalable architecture for building them, our discovery gives us a blueprint to shortcut our way to industrial scale quantum chip production.”
The experiments were performed by PhD student Virginia Ciriano Tejel (London Centre for Nanotechnology at UCL) and colleagues working in a low-temperature laboratory. During operation, the chips are kept in a refrigerated state, cooled to a fraction of a degree above absolute zero (?273 degrees Celsius).
Ms Ciriano Tejel said: “Every physics student learns in textbooks that electrons behave like tiny magnets with weird quantum properties, but nothing prepares you for the feeling of wonder in the lab, being able to watch this ‘spin’ of a single electron with your own eyes, sometimes pointing up, sometimes down. It’s thrilling to be a scientist trying to understand the world and at the same time be part of the development of quantum computers.”
A quantum computer harnesses laws of physics that are normally seen only at the atomic and subatomic level (for instance, that particles can be in two places simultaneously). Quantum computers could be more powerful than today’s super computers and capable of performing complex calculations that are otherwise practically impossible.
While the applications of quantum computing differ from traditional computers, they will enable us to be more accurate and faster in hugely challenging areas such as drug development and tackling climate change, as well as more everyday problems that have huge numbers of variables — just as in nature — such as transport and logistics.
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Whether parents prefer a conformance-oriented or independence-oriented supplemental education program for their children depends on political ideology, according to a study of more than 8,500 American parents by a research team from Rice University and the University of Texas at San Antonio.
“Conservative parents have a higher need for structure, which drives their preference for conformance-oriented programs,” said study co-author Vikas Mittal, a professor of marketing at Rice’s Jones Graduate School of Business. “Many parents are surprised to learn that their political identity can affect the educational choices they make for their children.”
Supplemental education programs include private tutoring, test preparation support and educational books and materials as well as online educational support services. The global market for private tutoring services is forecasted to reach $260.7 billion by 2024, and the U.S. market for tutoring is reported to be more than $8.9 billion a year. According to the Bureau of Labor Statistics, there are more than 100,000 businesses in the private education services industry. Supplemental education program brands are among the top 500 franchises in Entrepreneur magazine’s 2020 rankings, and they include popular providers such as Kumon (ranked No. 12), Mathnasium (No. 29) and Huntington Learning Center (No. 39).
For over five decades, education psychologists have utilized two pedagogical orientations — conformance orientation and independence orientation. A conformance orientation is more standardized and guided, emphasizing lecture-based content delivery, knowledge and memorization, frequent use of homework assignments, standardized examinations with relative evaluation and classroom attendance discipline and rules. In contrast, an independence orientation features discussion-based seminars and student-led presentations, an emphasis on ideas rather than facts, use of multimodal interaction instead of books, and highly variable and unstructured class routines. The two approaches do not differ in terms of topics covered in the curriculum or the specific qualities to be imparted to students.
The research team asked parents about their preferences for different programs framed as conformance- or independence-oriented. In five studies of more than 8,500 parents, conservative parents preferred education programs that were framed as conformance-oriented, while liberal parents preferred independence-oriented education programs. This differential preference emerged for different measures of parents’ political identity: their party affiliation, self-reported political leaning and whether they watch Fox or CNN/MSNBC for news.
“By understanding the underlying motivations behind parents’ preferences, educational programs’ appeal to parents can be substantially enhanced,” Mittal said. “Supplemental tutoring will be a major expenditure and investment for parents grappling with their child’s academic performance in the post-pandemic era. Informal conversations show parents gearing up to supplement school-based education with tutoring. Despite this, very little research exists about the factors that affect parents’ preference for and utilization of supplemental education.”
Mittal cautioned that these results do not speak to ultimate student performance. “This study only speaks to parents’ preferences but does not study ultimate student achievement,” he said.
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As social media platforms like Instagram, Snapchat, TikTok and others continue to grow in popularity, adolescents are spending more of their time online navigating a complex virtual world.
New research suggests that these increased hours spent online may be associated with cyberbullying behaviors. According to a study by the University of Georgia, higher social media addiction scores, more hours spent online, and identifying as male significantly predicted cyberbullying perpetration in adolescents.
“There are some people who engage in cyberbullying online because of the anonymity and the fact that there’s no retaliation,” said Amanda Giordano, principal investigator of the study and associate professor in the UGA Mary Frances Early College of Education. “You have these adolescents who are still in the midst of cognitive development, but we’re giving them technology that has a worldwide audience and then expecting them to make good choices.”
Cyberbullying can take on many forms, including personal attacks, harassment or discriminatory behavior, spreading defamatory information, misrepresenting oneself online, spreading private information, social exclusion and cyberstalking.
The study surveyed adolescents ranging in age from 13-19 years old. Of the 428 people surveyed, 214 (50%) identified as female, 210 (49.1%) as male, and four (0.9%) as other.
Exploring social media addiction
When adolescents are online, they adapt to a different set of social norms than when they’re interacting with their peers in person. Oftentimes, they are more aggressive or critical on social media because of the anonymity they have online and their ability to avoid retaliation. Additionally, cyberbullies may feel less remorse or empathy when engaging in these behaviors because they can’t see the direct impact of their actions. More