Researchers designed a wearable bracelet using sound augmentation to leverage play benefits by employing digital technology. The research team also investigated how sound influences children’s play experiences according to their physical, social, and imaginative aspects. More
Engineers have created a first-of-its-kind, flexible electronic sensing patch that can be sewn into clothing to analyze sweat for multiple markers. The patch could be used to to diagnose and monitor acute and chronic health conditions or to monitor athletic performance. More
Researchers have shown that an approach called federated learning is successful in the context of brain imaging, by being able to analyze magnetic resonance imaging (MRI) scans of brain tumor patients and distinguish healthy brain tissue from cancerous regions. More
New research has outlined three new approaches that digital innovators can take to reduce the risk of failure and seize competitive advantage in the industry. More
Even after 100 million years buried in the seafloor, some microbes can wake up. And they’re hungry.
An analysis of seafloor sediments dating from 13 million to nearly 102 million years ago found that nearly all of the microbes in the sediments were only dormant, not dead. When given food, even the most ancient microbes revived themselves and multiplied, researchers report July 28 in Nature Communications.
Scientists have pondered how long energy-starved microbes might survive within the seafloor. That such ancient microbes can still be metabolically active, the researchers say, just goes to show that scientists are still fathoming the most extreme limits to life on Earth.
The microbes’ patch of seafloor lies beneath a kind of ocean desert, part of a vast abyssal plain about 3,700 to 5,700 meters below sea level. Researchers, led by microbiologist Yuki Morono of the Japan Agency for Marine-Earth Science and Technology in Kochi, examined sediments collected in 2010 from part of the abyssal plain beneath the South Pacific Gyre. That region of the Pacific Ocean contains few nutrients that might fuel phytoplankton blooms and thereby support a cascade of ocean life. As a result, very little organic matter makes its way down through the water to settle on the seafloor.
The extremely slow accumulation of organic material and other sediments in this region does allow oxygen in the water to seep deep into the sediments. So Morono and colleagues wondered whether any aerobic, or oxygen-liking, microbes found there might be revivable. After “feeding” microbes from the collected sediments with nutrients including carbon and nitrogen, the team tracked the organisms’ activity based on what was consumed.
The aerobic microbes in the sediments turned out to be a highly diverse group, consisting mostly of different types of bacteria belonging to large groups such as Alphaproteobacteria and Gammaproteobacteria (SN: 9/14/17). Nearly all the microbes responded quickly to the food. By 68 days after the experiment’s start, the total number of microbial cells had increased by four orders of magnitude, from as little as about 100 cells per cubic centimeter to 1 million cells per cubic centimeter.
Those increases weren’t just among the youngest microbes. Even in the sediment sample containing the most elderly — about 101.5 million years old — up to 99.1 percent of the microbes were revived. More
The question has been central to cryptography for thousands of years, and lies at the heart of efforts to secure private information on the internet. In a new paper, Cornell Tech researchers identified a problem that holds the key to whether all encryption can be broken — as well as a surprising connection to a mathematical concept that aims to define and measure randomness.
“Our result not only shows that cryptography has a natural ‘mother’ problem, it also shows a deep connection between two quite separate areas of mathematics and computer science — cryptography and algorithmic information theory,” said Rafael Pass, professor of computer science at Cornell Tech.
Pass is co-author of “On One-Way Functions and Kolmogorov Complexity,” which will be presented at the IEEE Symposium on Foundations of Computer Science, to be held Nov. 16-19 in Durham, North Carolina.
“The result,” he said, “is that a natural computational problem introduced in the 1960s in the Soviet Union characterizes the feasibility of basic cryptography — private-key encryption, digital signatures and authentication, for example.”
For millennia, cryptography was considered a cycle: Someone invented a code, the code was effective until someone eventually broke it, and the code became ineffective. In the 1970s, researchers seeking a better theory of cryptography introduced the concept of the one-way function — an easy task or problem in one direction that is impossible in the other.
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For example, it’s easy to light a match, but impossible to return a burning match to its unlit state without rearranging its atoms — an immensely difficult task.
“The idea was, if we have such a one-way function, maybe that’s a very good starting point for understanding cryptography,” Pass said. “Encrypting the message is very easy. And if you have the key, you can also decrypt it. But someone who doesn’t know the key should have to do the same thing as restoring a lit match.”
But researchers have not been able to prove the existence of a one-way function. The most well-known candidate — which is also the basis of the most commonly used encryption schemes on the internet — relies on integer factorization. It’s easy to multiply two random prime numbers — for instance, 23 and 47 — but significantly harder to find those two factors if only given their product, 1,081.
It is believed that no efficient factoring algorithm exists for large numbers, Pass said, though researchers may not have found the right algorithms yet.
“The central question we’re addressing is: Does it exist? Is there some natural problem that characterizes the existence of one-way functions?” he said. “If it does, that’s the mother of all problems, and if you have a way to solve that problem, you can break all purported one-way functions. And if you don’t know how to solve that problem, you can actually get secure cryptography.”
Meanwhile, mathematicians in the 1960s identified what’s known as Kolmogorov Complexity, which refers to quantifying the amount of randomness or pattern of a string of numbers. The Kolmogorov Complexity of a string of numbers is defined as the length of the shortest computer program that can generate the string; for some strings, such as 121212121212121212121212121212, there is a short program that generates it — alternate 1s and 2s. But for more complicated and apparently random strings of numbers, such as 37539017332840393452954329, there may not exist a program that is shorter than the length of the string itself.
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The problem has long interested mathematicians and computer scientists, including Juris Hartmanis, professor emeritus of computer science and engineering. Because the computer program attempting to generate the number could take millions or even billions of years, researchers in the Soviet Union in the 1960s, as well as Hartmanis and others in the 1980s, developed the time-bounded Kolmogorov Complexity — the length of the shortest program that can output a string of numbers in a certain amount of time.
In the paper, Pass and doctoral student Yanyi Liu showed that if computing time-bounded Kolmogorov Complexity is hard, then one-way functions exist.
Although their finding is theoretical, it has potential implications across cryptography, including internet security.
“If you can come up with an algorithm to solve the time-bounded Kolmogorov complexity problem, then you can break all crypto, all encryption schemes, all digital signatures,” Pass said. “However, if no efficient algorithm exists to solve this problem, you can get a one-way function, and therefore you can get secure encryption and digital signatures and so forth.”
The research was funded in part by the National Science Foundation and the Air Force Office of Scientific Research, and was based on research funded by the Intelligence Advanced Research Projects Activity in the Office of the Director of National Intelligence. More
The simplicity and elegance of origami, an ancient Japanese art form, has motivated researchers to explore its application in the world of materials.
New research from an interdisciplinary team, including Northwestern Engineering’s Horacio Espinosa and Sridhar Krishnaswamy and the Georgia Institute of Technology’s Glaucio Paulino, aims to advance the creation and understanding of such folded structures for applications ranging from soft robotics to medical devices to energy harvesters.
Inspired by origami, mechanical metamaterials — artificial structures with mechanical properties defined by their structure rather than their composition — have gained considerable attention because of their potential to yield deployable and highly tunable structures and materials.
What wasn’t known was which structures integrate shape recoverability, pronounced directional mechanical properties, and reversible auxeticity — meaning their lateral dimensions can increase and then decrease when progressively squeezed. Though some 3D origami structures have been produced through additive manufacturing, achieving the folding properties displayed in ideal paper origami remained a challenge.
Using nanoscale effects for an origami design, the team of researchers from the McCormick School of Engineering and Georgia Tech sought to answer that question. They produced small, 3D, origami-built metamaterials, successfully retaining the best properties without resorting to artifacts to enable folding.
“The created structures constitute the smallest fabricated origami architected metamaterials exhibiting an unprecedented combination of mechanical properties,” said Espinosa, the James and Nancy J. Farley Professor of Manufacturing and Entrepreneurship and professor of mechanical engineering and (by courtesy) biomedical engineering and civil and environmental engineering.
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“Our work demonstrated that rational design of metamaterials, with a large degree of shape recoverability and direction-dependent stiffness and deformation, is possible using origami designs, and that origami foldability enables a state where the material initially expands and subsequently contracts laterally (reversible auxeticity),” added Espinosa, who serves as director of Northwestern’s Theoretical and Applied Mechanics graduate program. “Such properties promise to influence a number of applications across a wide range of fields encompassing the nano-, micro-, and macro-scales, leveraging the intrinsic scalability of origami assemblies.”
“Guided by geometry, the scaling and miniaturization of the origami metamaterial are exciting in itself and by the unprecedented multifunctionality that it naturally enables,” said Paulino, the Raymond Allen Jones Chair at Georgia Tech’s School of Civil and Environmental Engineering.
“Only an interdisciplinary effort combining origami design, 3D laser printing with nanoscale resolution, and in situ electron microscopy mechanical testing could reveal the unprecedented combination of properties our work demonstrated and their potential impact on future applications,” added Paulino, who contributed to establishing the National Science Foundation Emerging Frontiers in Research and Innovation program named ODISSEI (Origami Design for Integration of Self-assembling Systems for Engineering Innovation).
“Just like nature has architected a wide range of structures using just a few material systems, origami allows us to engineer resilient structural components with distinct physical properties along different directions,” said Krishnaswamy, professor of mechanical engineering.
“We can envision origami-based soft microrobots that are stiff along some directions to carry payloads while maintaining other degrees of flexibility for motion. Origami-metamaterials that exploit reversible auxeticity and large deformation can lead to multifunctional applications ranging from deployable microsurgical instruments and medical devices, to energy steering and harvesting,” added Krishnaswamy, the director of Northwestern’s Center for Smart Structures and Materials.
The study presents new avenues to be explored long term, Espinosa said.
“There are a number of possibilities,” he said. “One is the fabrication of origami structures with ceramic and metallic materials, while preserving nanoscale dimensions, to exploit size effects in the mechanical response of the structures leading to superior energy dissipation per unit volume and mass. Another is the use of piezoelectric polymers, which can result in energy harvesters that can drive sensing modalities or power microsurgical tools.” More
Humans have a hard time identifying individual birds just by looking at the patterns on their plumage. An international study involving scientists form the CNRS, Université de Montpellier and the University of Porto in Portugal, among others, has shown how computers can learn to differentiate individual birds of a same species. The results are published on 27 July 2020 in Methods in Ecology and Evolution.
Differentiating between individuals of a same species is essential in the study of wild animals, their processes of adaptation and behaviour. Scientists from the CEFE research centre in Ecology and Evolutionary Ecology (CNRS/ Université de Montpellier/ Université Paul-Valéry-Montpellier/ IRD/ EPHE) and the Research Centre in Biodiversity and Genetic Resources (CIBIO) at Porto University have for the very first time identified individual birds with the help of artificial intelligence technology.
They have developed a technique that enables them to gather a large number of photographs, taken from various angles, of individual birds wearing electronic tags. These images were fed into computers which used deep learning technology to recognise the birds by analysing the photographs. The computers were able to distinguish individual birds according to the patterns on their plumage, something humans can’t do. The technology was able to identify specimens from populations of three different species: sociable weavers, great tits and zebra finches.
This new technique could not only result in a less invasive method of identification but also lead to new insights in ecology, for example, by opening ways of using AI to study animal behaviour in the wild.
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Materials provided by CNRS. Note: Content may be edited for style and length. More
