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Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 10:58am

Using softened wood to create electricity in homes

A multi-institutional team of researchers has found that it is possible to use a type of fungus to soften wood to the point that it could be used to generate electricity. In their paper published in the journal Science Advances, the group describes their process and how they tested it.

As the world works its way toward cleaner energy-producing systems, scientists seek novel approaches to producing electricity. One possibility is the use of piezoelectric devices that generate electricity by harnessing movement such as footsteps. In this new effort, the researchers have noted that much energy is wasted when people walk around. And while some have attempted to harness some of that energy with devices designed for shoes or legs, the researchers with this new effort wondered if it might be possible to add piezoelectrics to the floor to make use of that energy.

In studying the kinds of wood that are used to make floors, particularly in homes, the researchers noted that they do not have much give—a necessary component of an energy-harvesting system. To solve that problem, they found that applying a type of white rot fungus to pieces of balsa wood for a few weeks sped up the decaying process in a useful way. It made the wood spongier, which translated to give. When stepping on the wood, the researchers could feel it depress. They also found that after the wood returned to its former shape when pressure was removed.

To test their idea, the researchers treated a wooden veneer with the fungus and then added a piezoelectric device, which sent the power it produced through a wire attached to an LED light. The wood was then placed on a floor where people could walk on it. Each time they did so, the light came on. The researchers note that the amount of electricity generated was just 0.85 volts but the system could very easily be scaled up to include all the flooring in a home, generating enough electricity, perhaps, to power certain devices.

Jianguo Sun et al. Enhanced mechanical energy conversion with selectively decayed wood, Science Advances (2021). DOI: 10.1126/sciadv.abd9138

https://techxplore.com/news/2021-03-softened-wood-electricity-homes...

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Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 10:27am

How to spot deepfakes? Look at light reflection in the eyes

Computer scientists have developed a tool that automatically identifies deepfake photos by analyzing light reflections in the eyes.

The tool proved 94% effective with portrait-like photos in experiments described in a paper accepted at the IEEE International Conference on Acoustics, Speech and Signal Processing to be held in June in Toronto, Canada.

The cornea is almost like a perfect semisphere and is very reflective. So, anything that is coming to the eye with a light emitting from those sources will have an image on the cornea. The two eyes should have very similar reflective patterns because they're seeing the same thing. It's something that we typically don't typically notice when we look at a face.

When we look at something, the image of what we see is reflected in our eyes. In a real photo or video, the reflections on the eyes would generally appear to be the same shape and color.

However, most images generated by artificial intelligence—including generative adversary network (GAN) images—fail to accurately or consistently do this, possibly due to many photos combined to generate the fake image.

Now the researchers tool exploits this shortcoming by spotting tiny deviations in reflected light in the eyes of deepfake images.

While promising, this new technique has limitations.

For one, you need a reflected source of light. Also, mismatched light reflections of the eyes can be fixed during editing of the image. Additionally, the technique looks only at the individual pixels reflected in the eyes—not the shape of the eye, the shapes within the eyes, or the nature of what's reflected in the eyes.

Finally, the technique compares the reflections within both eyes. If the subject is missing an eye, or the eye is not visible, the technique fails.

Exposing GAN-generated Faces Using Inconsistent Corneal Specular Highlights. arXiv:2009.11924v2 [cs.CV] arxiv.org/abs/2009.11924

https://techxplore.com/news/2021-03-deepfakes-eyes.html?utm_source=...

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 10:14am

Classic math problem solved: Computer scientists have developed a s...

One of the most classic algorithmic problems deals with calculating the shortest path between two points. A more complicated variant of the problem is when the route traverses a changing network—whether this be a road network or the internet. For 40 years, researchers have sought an algorithm that provides an optimal solution to this problem. Now, computer scientist Christian Wulff-Nilsen of the University of Copenhagen and two research colleagues have come up with a recipe.

When heading somewhere new, most of us leave it to computer algorithms to help us find the best route, whether by using a car's GPS, or public transport and map apps on their phone. Still, there are times when a proposed route doesn't quite align with reality. This is because road networks, public transportation networks and other networks aren't static. The best route can suddenly be the slowest, e.g. because a queue has formed due to roadworks or an accident.

People probably don't think about the complicated math behind routing suggestions in these types of situations. The software being used is trying to solve a variant for the classic algorithmic "shortest path" problem, the shortest path in a dynamic network. For 40 years, researchers have been working to find an algorithm that can optimally solve this mathematical conundrum. Now, Christian Wulff-Nilsen of the University of Copenhagen's Department of Computer Science has succeeded in cracking the nut along with two colleagues.

The researchers represent a network as a so-called dynamic graph. In this context, a graph is an abstract representation of a network consisting of edges, roads for example, and nodes, representing intersections, for example. When a graph is dynamic, it means that it can change over time. The new algorithm handles changes consisting of deleted edges—for example, if the equivalent of a stretch of a road suddenly becomes inaccessible due to road work.

Traditional algorithms assume that a graph is static, which is rarely true in the real world. When these kinds of algorithms are used in a dynamic network, they need to be rerun every time a small change occurs in the graph—which wastes time.

Aaron Bernstein, et al. Near-Optimal Decremental SSSP in Dense Weighted Digraphs. arXiv:2004.04496v2 [cs.DS] arxiv.org/abs/2004.04496

https://techxplore.com/news/2021-03-classic-math-problem-scientists...

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 10:10am

The secrets of the best rainbows on Earth

Why Hawai'i the rainbow capital of the world

Rainbows are some of the most spectacular optical phenomena in the natural world

Hawai'i's location in the subtropical Pacific means the overall weather pattern is dominated by trade winds, with frequent rain showers and clear skies between the showers.

Businger outlines four additional factors affecting the prevalence of rainbows throughout the islands.

"At night a warm sea surface heats the atmosphere from below, while radiation to space cools cloud tops, resulting in deeper rain showers in the morning that produce rainbows in time for breakfast," said Businger.

Another critical factor in producing frequent rainbows is Hawai'i's mountains, which cause trade wind flow to be pushed up, forming clouds and producing rainfall. Without mountains, Hawai'i would be a desert with a scant 17 inches annual rainfall.

A third factor conducive to rainbow sightings is daytime heating, which drives island-scale circulations. During periods of lighter winds, showers form over the ridge crests over Oahu and Kauai in the afternoon, resulting in prolific rainbows as the sun sets.

Due to the remoteness of the Hawaiian Islands, the air is exceptionally clean and free of pollution, continental dust, and pollen. This is the fourth factor that contributes to the numerous bright rainbows with the full spectrum of colors.

Steven Businger, The Secrets of the Best Rainbows on Earth, Bulletin of the American Meteorological Society (2020). DOI: 10.1175/BAMS-D-20-0101.1

https://phys.org/news/2021-03-secrets-rainbows-earth.html?utm_sourc...

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Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 10:00am

Foodborne fungus impairs intestinal wound healing in Crohn's disease

Eating is a dangerous business. Naturally occurring toxins in food and potentially harmful foodborne microbes can do a number on our (injure) intestines, leading to repeated minor injuries. In healthy people, such damage typically heals in a day or two. But in people with Crohn's disease, the wounds fester, causing abdominal pain, bleeding, diarrhea and other unpleasant symptoms.

Crohn's is a subtype of inflammatory bowel disease. As the name suggests, it is driven by chronic inflammation in the digestive tract and primarily treated with immunosuppressive medications. Crohn's patients endure repeated cycles of gastrointestinal symptom flare-up and remission. During a flare, their digestive tracts are dotted with inflamed, open sores that can persist for weeks or even months.

Researchers discovered that a fungus found in foods such as cheese and processed meats can infect sites of intestinal damage in mice and people with Crohn's and prevent healing. Moreover, treating infected mice with antifungal medication eliminates the fungus and allows the wounds to heal.

The findings, published March 12 in the journal Science, suggest that antifungal drugs and dietary changes are potential new approaches to improving intestinal wound healing and reducing symptoms of Crohn's disease.

 U. Jain el al., "Debaryomyces is enriched in Crohn's disease intestinal tissue and impairs healing in mice," Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abd0919

https://medicalxpress.com/news/2021-03-foodborne-fungus-impairs-int...

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 9:43am

Observing the birth of a quasiparticle

Over the past decades, physicists worldwide have been trying to gain a better understanding of non-equilibrium dynamics in quantum many-body systems. Some studies investigated what are known as quasiparticles, disturbances or entities in physical systems that exhibit behavior similar to that of particles.

Researchers at Aarhus University recently carried out a study investigating the non-equilibrium dynamics of a quantum impurity immersed in a bosonic environment. Their paper, published in Nature Physics, sheds light on the dynamical behavior of interacting many-body systems, while also improving the current understanding of how Bose polarons are formed.

Quasiparticles are extremely interesting, since they may consist of countless particles and their excitations.

The idea of quasiparticles was first introduced in the 1930s by physicist Lev Landau, who was trying to gain a better understanding of complex quantum systems. The experiments carried out now build on models created by Landau.

In their studies, the researchers prepared coherent superposition states of atoms in a Bose-Einstein condensate with a small impurity-state component using an interferometric technique. Subsequently, they monitored the evolution of these quantum superpositions and their transition into polaronic quasiparticles.

Remarkably, the researchers were able to observe the birth of a unique class of quasiparticles, called Bose polarons, for the very first time. While in the past several research groups detected signs of these quasiparticles in laboratory settings, so far observing their gradual formation over time proved highly challenging, mainly because the processes through which they are formed are exceedingly fast.

Non-equilibrium quantum dynamics and formation of the Bose polaron. Nature Physics(2021). DOI: 10.1038/s41567-021-01184-5.

Bipolarons in a Bose-Einstein condensate. Physical Review Letters(2018).
DOI: 10.1103/PhysRevLett.121.013401.

Observation of attractive and repulsive polarons in a Bose-Einstein condensate. Physical Review Letters(2016). DOI: 10.1103/PhysRevLett.117.055302.

Bose polarons in the strongly interacting regime. Physical Review Letters(2016). DOI: 10.1103/PhysRevLett.117.055301.

Bose polarons near quantum criticality. Science(2020). DOI: 10.1126/science.aax5850.

https://phys.org/news/2021-03-birth-quasiparticle.html?utm_source=n...

Comment by Dr. Krishna Kumari Challa on March 11, 2021 at 12:45pm

The Chemical Origins of Life

How did life get started on Earth? And how are we using what we know to look for it throughout the galaxy?

Comment by Dr. Krishna Kumari Challa on March 11, 2021 at 11:20am

A scarf that speaks? Scientists develop message display fabric

At first glance, the fabric looks like a pretty if not especially original scarf, with turquoise, blue and orange stripes in an open weave. But this fabric can communicate.

It's wearable, foldable and washable, but it's also a fully functioning display—capable of flashing messages or images, or even being used with a keyboard.

it could revolutionize communication and "help individuals with voice, speech or language difficulties to express themselves to others".

Large-area display textiles integrated with functional systems, Nature (2021). DOI: 10.1038/s41586-021-03295-8 , dx.doi.org/10.1038/s41586-021-03295-8

https://techxplore.com/news/2021-03-scarf-scientists-message-fabric...

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Comment by Dr. Krishna Kumari Challa on March 11, 2021 at 11:14am

Face masks are a ticking plastic timebomb

Recent studies estimate that we use an astounding 129 billion face masks globally every month—that is 3 million a minute. Most of them are disposable face masks made from plastic microfibers.

With increasing reports on inappropriate disposal of masks, it is urgent to recognize this potential environmental threat and prevent it from becoming the next plastic problem.

Disposable masks are plastic products, that cannot be readily biodegraded but may fragment into smaller plastic particles, namely micro- and nanoplastics that widespread in ecosystems.

The enormous production of disposable masks is on a similar scale as plastic bottles, which is estimated to be 43 billion per month. However, different from plastic bottles, (of which app. 25 pct. is recycled), there is no official guidance on mask recycle, making it more likely to be disposed of as solid waste

If not disposed of for recycling, like other plastic wastes, disposable masks can end up in the environment, freshwater systems, and oceans, where weathering can generate a large number of micro-sized particles (smaller than 5 mm) during a relatively short period (weeks) and further fragment into nanoplastics (smaller than 1 micrometer).

"A newer and bigger concern is that the masks are directly made from microsized plastic fibers (thickness of ~1 to 10 micrometers). When breaking down in the environment, the mask may release more micro-sized plastics, easier and faster than bulk plastics like plastic bags.

How can you solve it?

Researchers recommend these solutions:

1. Set up mask-only trash cans for collection and disposal
2. consider standardization, guidelines, and strict implementation of waste management for mask wastes
3. replace disposable masks with reusable face masks like cotton masks
4. consider development of biodegradable disposal masks.

Elvis Genbo Xu et al, Preventing masks from becoming the next plastic problem, Frontiers of Environmental Science & Engineering (2021). DOI: 10.1007/s11783-021-1413-7

https://phys.org/news/2021-03-masks-plastic-timebomb.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on March 11, 2021 at 11:02am

Bacteria know how to exploit quantum mechanics, study finds

Photosynthetic organisms harvest light from the sun to produce the energy they need to survive. A new paper published by University of Chicago researchers reveals their secret: exploiting quantum mechanics.

Before this study, the scientific community saw quantum signatures generated in biological systems and asked the question, were these results just a consequence of biology being built from molecules, or did they have a purpose?" said Greg Engel, Professor of Chemistry and senior author on the study. "This is the first time we are seeing biology actively exploiting quantum effects.

The scientists studied a type of microorganism called green sulfur bacteria. These bacteria need light to survive, but even small amounts of oxygen can damage their delicate photosynthetic equipment. So they must develop ways to minimize the damage when the bacterium does encounter oxygen.

To study this process, researchers tracked the movement of energy through a photosynthetic protein under different conditions—with oxygen around, and without.

They found that the bacterium uses a quantum mechanical effect called vibronic mixing to move energy between two different pathways, depending on whether or not there's oxygen around. Vibronic mixing involves vibrational and electronic characteristics in molecules coupling to one another. In essence, the vibrations mix so completely with the electronic states that their identities become inseparable. This bacterium uses this phenomenon to guide energy where it needs it to go.

If there's no oxygen around and the bacterium is safe, the bacterium uses vibronic mixing by matching the energy difference between two electronic states in an assembly of molecules and proteins called the FMO complex, with the energy of the vibration of a bacteriochlorophyll molecule. This encourages the energy to flow through the 'normal' pathway toward the photosynthetic reaction center, which is packed full of chlorophyll.

But if there is oxygen around, the organism has evolved to steer the energy through a less direct path where it can be quenched. (Quenching energy is similar to putting a palm on a vibrating guitar string to dissipate energy.) This way, the bacterium loses some energy but saves the entire system.

Jacob S. Higgins et al, Photosynthesis tunes quantum-mechanical mixing of electronic and vibrational states to steer exciton energy transfer, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2018240118

https://phys.org/news/2021-03-bacteria-exploit-quantum-mechanics.ht...

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