Archive for the ‘biological’ category: Page 8

Jun 28, 2023

Researchers observe rubber-like elasticity in liquid glycerol for the first time

Posted by in categories: biological, engineering

Simple molecular liquids such as water or glycerol are of great importance for technical applications, in biology or even for understanding properties in the liquid state. Researchers at the Max Planck Institut für Struktur und Dynamik der Materie (MPSD) have now succeeded in observing liquid glycerol in a completely unexpected rubbery state.

In their article published in Proceedings of the National Academy of Sciences, the researchers report how they created rapidly expanding on the surface of the liquid in vacuum using a pulsed laser. However, the thin, micrometers-thick liquid envelope of the bubble did not behave like a viscous liquid dissipating deformation energy as expected, but like the elastic envelope of a rubber toy balloon, which can store and release elastic energy.

It is the first time an elasticity dominating the flow behavior in a Newtonian liquid like glycerol has been observed. Its existence is difficult to reconcile with common ideas about the interactions in liquid glycerol and motivates the search for more comprehensive descriptions. Surprisingly, the elasticity persists over such long timescales of several microseconds that it could be important for very rapid engineering applications such as micrometer-confined flows under . Yet, the question remains unsettled whether this behavior is a specific property of liquid glycerol, or rather a phenomenon that occurs in many molecular liquids under similar conditions but has not been observed so far.

Jun 27, 2023

How uploading our minds to a computer might become possible

Posted by in categories: biological, computing, neuroscience

The idea that our mind could live on in another form after our physical body dies has been a recurring theme in science fiction since the 1950s. Recent television series such as Black Mirror and Upload, as well as some games, demonstrate our continued fascination with this idea. The concept is known as mind uploading.

Recent developments in science and technology are taking us closer to a time when mind uploading could graduate from science fiction to reality.

In 2016, BBC Horizon screened a programme called The Immortalist, in which a
Russian millionaire unveiled his plans to work with neuroscientists, robot builders and other experts to create technology that would allow us to upload our minds to a computer in order to live forever.

Continue reading “How uploading our minds to a computer might become possible” »

Jun 25, 2023

Technology Roadmap for Flexible Sensors

Posted by in categories: biological, information science

Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks.

Jun 24, 2023

Alan Turing and the Limits of Computation

Posted by in categories: biological, mathematics, robotics/AI

Note: June 23 is Alan Turing’s birth anniversary.

Alan Turing wore many scientific hats in his lifetime: a code-breaker in World War II, a prophetic figure of artificial intelligence (AI), a pioneer of theoretical biology, and a founding figure of theoretical computer science. While the former of his roles continue to catch the fancy of popular culture, his fundamental contribution to the development of computing as a mathematical discipline is possibly where his significant scientific impact persists to date.

Jun 23, 2023

In a first, scientists use AI to create brand new enzymes

Posted by in categories: biological, chemistry, robotics/AI

In a scientific first, researchers have used machine learning-powered AI to design de novo enzymes — never-before-existing proteins that accelerate biochemical reactions in living organisms. Enzymes drive a wide range of critical processes, from digestion to building muscle to breathing.

A team led by the University of Washington’s Institute for Protein Design, along with colleagues at UCLA and China’s Xi’an Jiaotong University, used their AI engine to create new enzymes of a kind called luciferases. Luciferases — as their name implies — catalyze chemical reactions that emit light; they’re what give fireflies their flare.

“Living organisms are remarkable chemists,” David Baker, a professor of biochemistry at UW and the study’s senior author, said.

Jun 21, 2023

“Hydration Solids”: The New Class of Matter Shaking Up Science

Posted by in categories: biological, chemistry, particle physics, science

For many years, the fields of physics and chemistry have held the belief that the properties of solid materials are fundamentally determined by the atoms and molecules they consist of. For instance, the crystalline nature of salt is credited to the ionic bond formed between sodium and chloride ions. Similarly, metals such as iron or copper owe their robustness to the metallic bonds between their respective atoms, and the elasticity of rubbers stems from the flexible bonds in the polymers that form them. This principle also applies to substances like fungi, bacteria, and wood.

Or so the story goes.

A new paper recently published in Nature upends that paradigm, and argues that the character of many biological materials is actually created by the water that permeates these materials. Water gives rise to a solid and goes on to define the properties of that solid, all the while maintaining its liquid characteristics.

Jun 19, 2023

Resurrection — Scientists Discover It Is Not Due to a “Miracle Gene”

Posted by in category: biological

Certain plant species.

A species is a group of living organisms that share a set of common characteristics and are able to breed and produce fertile offspring. The concept of a species is important in biology as it is used to classify and organize the diversity of life. There are different ways to define a species, but the most widely accepted one is the biological species concept, which defines a species as a group of organisms that can interbreed and produce viable offspring in nature. This definition is widely used in evolutionary biology and ecology to identify and classify living organisms.

Jun 16, 2023

We Finally Know How Photosynthesis Starts: It Takes Just a Single Photon

Posted by in categories: biological, chemistry, quantum physics

During photosynthesis, a symphony of chemicals transforms light into the energy required for plant, algal, and some bacterial life. Scientists now know that this remarkable reaction requires the smallest possible amount of light – just one single photon – to begin.

A US team of researchers in quantum optics and biology showed that a lone photon can start photosynthesis in the purple bacterium Rhodobacter sphaeroides, and they are confident it works in plants and algae since all photosynthetic organisms share an evolutionary ancestor and similar processes.

The team says their findings bolster our knowledge of photosynthesis and will lead to a better understanding of the intersection of quantum physics in a wide range of complex biological, chemical, and physical systems, including renewable fuels.

Jun 15, 2023

Aging — what it is and how to measure it

Posted by in categories: biological, life extension

The current understanding of the biology of aging is largely based on research aimed at identifying factors that influence lifespan. However, lifespan as a sole proxy measure of aging has limitations because it can be influenced by specific pathologies (not generalized physiological deterioration in old age). Hence, there is a great need to discuss and design experimental approaches that are well-suited for studies targeting the biology of aging, rather than the biology of specific pathologies that restrict the lifespan of a given species. For this purpose, we here review various perspectives on aging, discuss agreement and disagreement among researchers on the definition of aging, and show that while slightly different aspects are emphasized, a widely accepted feature, shared across many definitions, is that aging is accompanied by phenotypic changes that occur in a population over the course of an average lifespan. We then discuss experimental approaches that are in line with these considerations, including multidimensional analytical frameworks as well as designs that facilitate the proper assessment of intervention effects on aging rate. The proposed framework can guide discovery approaches to aging mechanisms in all key model organisms (e.g., mouse, fish models, D. melanogaster, C. elegans) as well as in humans.

Keywords: Aging; experimental design; lifespan; models; phenotypes.

Copyright © 2023 Elsevier B.V. All rights reserved.

Jun 14, 2023

Mean-shift exploration in shape assembly of robot swarms Communications

Posted by in categories: biological, information science, robotics/AI, transportation

The fascinating collective behaviors of biological systems have inspired extensive studies on shape assembly of robot swarms6,7,8,9. One class of strategies widely studied in the literature are based on goal assignment in either centralized or distributed ways10,11,12. Once a swarm of robots are assigned unique goal locations in a desired shape, the consequent task is simply to plan collision-free trajectories for the robots to reach their goal locations10 or conduct distributed formation control based on locally sensed information6,13,14. It is notable that centralized goal assignment is inefficient to support large-scale swarms since the computational complexity increases rapidly as the number of robots increases15,16. Moreover, when robots fail to function normally, additional algorithms for fault-tolerant detection and goal re-assignment are required to handle such situations17. As a comparison, distributed goal assignment can support large-scale swarms by decomposing the centralized assignment into multiple local ones11,12. It also exhibits better robustness to robot faults. However, since distributed goal assignments are based on locally sensed information, conflicts among local assignments are inevitable and must be resolved by sophisticated algorithms such as local task swapping11,12.

Another class of strategies for shape assembly that have also attracted extensive research attention are free of goal assignment18,19,20,21. For instance, the method proposed in ref. 18 can assemble complex shapes using thousands of homogeneous robots. An interesting feature of this method is that it does not rely on external global positioning systems. Instead, it establishes a local positioning system based on a small number of pre-localized seed robots. As a consequence of the local positioning system, the proposed edge-following control method requires that only the robots on the edge of a swarm can move while those inside must stay stationary. The method in ref. 19 can generate swarm shapes spontaneously from a reaction-diffusion network similar to embryogenesis in nature. However, this method is not able to generate user-specified shapes precisely. The method in ref. 21 can aggregate robots on the frontier of shapes based on saliency detection. The user-defined shape is specified by a digital light projector. An interesting feature of this method is that it does not require centralized edge detectors. Instead, edge detection is realized in a distributed manner by fusing the beliefs of a robot with its neighbors. However, since the robots cannot self-localize themselves relative to the desired shape, they make use of random walks to search for the edges, which would lead to random trajectories. Another class of methods that do not require goal assignment is based on artificial potential fields22,23,24,25. One limitation of this class of methods is that robots may easily get trapped in local minima, making it difficult to assemble nonconvex complex shapes.

Here, we propose a strategy for shape assembly of robot swarms based on the idea of mean-shift exploration: when a robot is surrounded by neighboring robots and unoccupied locations, it would actively give up its current location by exploring the highest density of nearby unoccupied locations in the desired shape. This idea does not rely on goal assignment. It is realized by adapting the mean-shift algorithm26,27,28, which is an optimization technique widely used in machine learning for locating the maxima of a density function. Moreover, a distributed negotiation mechanism is designed to allow robots to negotiate the final desired shape with their neighbors in a distributed manner. This negotiation mechanism enables the swarm to maneuver while maintaining a desired shape based on a small number of informed robots. The proposed strategy empowers robot swarms to assemble nonconvex complex shapes with strong adaptability and high efficiency, as verified by numerical simulation results and real-world experiments with swarms of 50 ground robots. The strategy can be adapted to generate interesting behaviors including shape regeneration, cooperative cargo transportation, and complex environment exploration.

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