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Comment by Dr. Krishna Kumari Challa on February 16, 2023 at 11:46am

Study: The faster El Niño decays, the fewer typhoons occur the following summer

As the largest climate signal on the interannual time scale, El Niño has pronounced impacts on typhoon activity. Recently, a growing number of studies have been focusing on the climatic effects of the pace of El Niño decay and the remarkable role this plays in the genesis position and intensity variations of typhoons. However, the response of the frequency of typhoon occurrence to the pace of El Niño decay remains unclear.

In a paper recently published in Atmospheric and Oceanic Science Letters, scientists attempted to address this issue. They present new evidence for variation in the pace of El Niño decay having a significant influence on the typhoon frequency in the summer following the mature winter of El Niño.

Firstly they classified El Niño cases into two categories: fast decaying [FD] and slow decaying [SD]. Interestingly, the typhoon occurrence frequency decreased sharply in the following summer only for FD El Niño cases. In order to explore the possible reason for this observed typhoon response, tehy further compared the environmental factors for typhoon development and the related atmospheric circulation processes between the FD and SD El Niño years.

Compared with those for SD El Niño years, fewer typhoons occurred in the following summer for FD El Niño years, and the causal mechanism was a stronger anticyclonic anomaly over the western North Pacific forced by tropical Indo-Pacific sea surface temperature (SST) anomalies. Therefore, the pace of El Niño decay might serve as an important factor in the prediction of typhoon activity.

However, the question of how these distinct patterns of tropical SST anomalies establish under FD and SD El Niño conditions needs to be studied in future work from the perspective of ocean dynamics.

Qun Zhou et al, Influence of the pace of El Niño decay on tropical cyclone frequency over the western north pacific during decaying El Niño summers, Atmospheric and Oceanic Science Letters (2023). DOI: 10.1016/j.aosl.2023.100328

Comment by Dr. Krishna Kumari Challa on February 16, 2023 at 11:32am

Discovering the magic in superconductivity's 'magic angle'

Researchers have produced new evidence of how graphene, when twisted to a precise angle, can become a superconductor, moving electricity with no loss of energy.

They reported on their finding of the key role that quantum geometry plays in allowing this twisted graphene to become a superconductor. 

Graphene is a single layer of carbon atoms, the lead that is found in a pencil.

In 2018, scientists at the Massachusetts Institute of Technology discovered that, under the right conditions, graphene could become a superconductor if one piece of graphene were laid on top of another piece and the layers were twisted to a specific angle—1.08 degrees—creating twisted bilayer graphene.

Ever since, scientists have been studying this twisted bilayer graphene and trying to figure out how this 'magic angle' works. The conventional theory of superconductivity doesn't work in this situation. so scientists  did a series of experiments to understand the origins of why this material is a superconductor. 

In a conventional metal, high-speed electrons are responsible for conductivity.

But twisted bilayer graphene has a type of electronic structure known as a "flat band" in which the electrons move very slowly—in fact at a speed that approaches zero if the angle is exactly at the magic one.

Under the conventional theory of superconductivity, electrons moving this slowly should not be able to conduct electricity.

With great precision the research group was able to obtain a device so close to the magic angle that the electrons were nearly stopped by usual condensed matter physics standards. The sample nevertheless showed superconductivity.

It is a paradox: How can electrons which move so slowly conduct electricity at all, let alone superconduct? It is very remarkable.

In their experiments, the research team demonstrated the slow speeds of the electrons and gave more precise measurements of electron movement than had been previously available.

And they also found the first clues as to what makes this graphene material so special.

They couldn't use the speed of electrons to explain how the twisted bilayer graphene is working. Instead, they had to use quantum geometry.

As with everything quantum, quantum geometry is complex and not intuitive. But the results of this study have to do with the fact that an electron is not only a particle, but also a wave—and thus has wavefunctions.

The geometry of the quantum wavefunctions in flat bands, together with the interaction between electrons, leads to the flow of electrical current without dissipation in bilayer graphene.

Their  experimental measurements suggest quantum geometry is 90% of what makes this a superconductor.

 Chun Lau, Evidence for Dirac flat band superconductivity enabled by quantum geometry, Nature (2023). DOI: 10.1038/s41586-022-05576-2. www.nature.com/articles/s41586-022-05576-2

Comment by Dr. Krishna Kumari Challa on February 16, 2023 at 10:44am

Food coloring and anti-caking nanoparticles may affect the human gut

Metal oxide nanoparticles—ubiquitous in nature, and commonly used as food coloring and anti-caking agents in the commercial ingredients industry—may damage and disturb parts of the human intestine, according to new research conducted by  scientists.

They  found that specific nanoparticles—titanium dioxide and silicon dioxide—ordinarily used in food may negatively affect intestinal functionality. They have a negative effect on key digestive and absorptive proteins. 

In their research, the group used human-relevant doses of titanium dioxide and silicon dioxide in the Tako laboratory's in vivo system, which offers a health response similar to the human body's.

The scientists injected the nanoparticles into chicken eggs. After the chickens hatched, the scientists detected changes in the functional, morphological and microbial biomarkers in the blood, the duodenum (upper intestine) and the cecum (a pouch connected to the intestine).

The scientists found shifts in the composition of intestinal bacterial populations. The animals' mineral transport was affected and the brush border membrane (the intestine's digestive and absorptive surface) was disturbed.

Additionally, the group examined zinc oxide, a micronutrient, and iron oxide, an iron fortification supplement. Zinc oxide nanoparticles support intestinal development, as well as a compensatory mechanism following intestinal damage. Iron oxide nanoparticles are a potential option for iron fortification, though with potential alterations in intestinal functionality and health.

The scientists are not advocating for ending the use of these nano particles.

Based on the information, they are suggesting to simply being aware. Science needs to conduct further investigations based on their findings. They are opening the door for discussion.

Jacquelyn Cheng et al, Food-Grade Metal Oxide Nanoparticles Exposure Alters Intestinal Microbial Populations, Brush Border Membrane Functionality and Morphology, In Vivo (Gallus gallus), Antioxidants (2023). DOI: 10.3390/antiox12020431

Comment by Dr. Krishna Kumari Challa on February 15, 2023 at 10:58am

Snakes can hear more than you think

A new  study has found that as well as ground vibrations, snakes can hear and react to airborne sound.

Because snakes don't have external ears, people typically think they're deaf and can only feel vibrations through the ground and into their bodies.

But this new research—the first of its kind using non-anesthetized, freely moving snakes—found they do react to soundwaves traveling through the air, and possibly human voices.

Researchers  played three different sound frequencies to captive-bred snakes one at a time in a soundproof room and observed their reactions. The study involved 19 snakes, representing five genetic families of reptile.

 They played one sound which produced ground vibrations, while the other two were airborne only. It meant researchers  were able to test both types of 'hearing'—tactile hearing through the snakes' belly scales and airborne through their internal ear.

The reactions strongly depended on the genus of the snakes.

Only the woma python tended to move toward sound, while taipans, brown snakes and especially death adders were all more likely to move away from it. The types of behavioral reactions also differed, with taipans in particular more likely to exhibit defensive and cautious responses to sound.

The different reactions are likely because of evolutionary pressures over millions of years, designed to aid survival and reproduction.

For example, woma pythons are large nocturnal snakes with fewer predators than smaller species and probably don't need to be as cautious, so they tended to approach sound. But taipans may have to worry about raptor predators and they also actively pursue their prey, so their senses seem to be much more sensitive.

These new  the findings challenge the assumption that snakes can't hear sound, such as humans talking or yelling, and could reshape the view on how they react to sound.

 PLoS ONE (2023). DOI: 10.1371/journal.pone.pone.0281285

Comment by Dr. Krishna Kumari Challa on February 15, 2023 at 10:29am

We really need this : New AI tool guides users away from vitriol

To help identify when tense online debates are inching toward irredeemable meltdown,  researchers have developed an artificial intelligence tool that can track these conversations in real-time, detect when tensions are escalating and nudge users away from using incendiary language.

Detailed in two recently published papers that examine AI's effectiveness in moderating online discussions, the research shows promising signs that conversational forecasting methods within the field of natural language processing could prove useful in helping both moderators and users proactively lessen vitriol and maintain healthy, productive debate forums.

The tool, named ConvoWizard, is a browser extension powered by a deep neural network. That network was trained on mountains of language-based data pulled from the subreddit Change My View, a forum that prioritizes good faith debates on potentially heated subjects related to politics, economics and culture.

When participating Change My View users enable ConvoWizard, the tool can inform them when their conversation is starting to get tense. It can also inform users, in real-time as they are writing their replies, whether their comment is likely to escalate tension. The study suggests that AI-powered feedback can be effective in guiding the user toward language that elevates constructive debate, researchers say.

Jonathan P. Chang et al, Thread With Caution: Proactively Helping Users Assess and Deescalate Tension in Their Online Discussions, Proceedings of the ACM on Human-Computer Interaction (2022). DOI: 10.1145/3555603

Charlotte Schluger et al, Proactive Moderation of Online Discussions: Existing Practices and the Potential for Algorithmic Support, Proceedings of the ACM on Human-Computer Interaction (2022). DOI: 10.1145/3555095

Comment by Dr. Krishna Kumari Challa on February 15, 2023 at 9:48am

In the experiments now published, a special detection was used. "The energy released during the decay of the state is sufficient to release other electrons from the nanostructure.

The triggered electrons could then be captured in an image using a photoemission electron microscope and a resolution of a few nanometers. Because of the fast decay times, sequences of ultrashort laser pulses were used to obtain the "fingerprint" of the superposition states of the light.

This is a first step toward the goal of analyzing the full quantum physical state of coupled photon and electrons directly at the nanoscale. 

Sebastian Pres et al, Detection of a plasmon-polariton quantum wave packet, Nature Physics (2023). DOI: 10.1038/s41567-022-01912-5

Part 2

Comment by Dr. Krishna Kumari Challa on February 15, 2023 at 9:47am

The weird world of Quantum Mechanics: When the light is neither 'on' nor 'off' in the nanoworld!

Whether the light in our living spaces is on or off can be regulated in everyday life simply by reaching for the light switch. However, when the space for the light is shrunk to a few nanometers, quantum mechanical effects dominate, and it is unclear whether there is light in it or not. Both can even be the case at the same time, as scientists show in the journal Nature Physics.

The technology of our digital world is based on the principle that either a current flows or it does not: one or zero, on or off. Two clear states exist. In quantum physics, on the other hand, it is possible to disregard this principle and create an arbitrary superposition of the supposed opposites. This increases the possibilities of transmitting and processing information many times over. Such superposition states have been known for some time, especially for the particles of light, so-called photons, and are used in the detection of gravitational waves.

A team of physicists and physical chemists from Bielefeld and Würzburg has now succeeded in detecting such superposition states of light directly in a nanostructure. Light is captured in a nanostructure in a very small space and couples to electronic oscillations: so-called plasmons. This allows the energy of the light to be held in place on the nanoscale.

In the experiment, the researchers investigated how many photons from a light pulse couple to the nanostructure. The result: simultaneously no photon and three photons.

Detecting this signature was an enormous challenge. Photons can be detected very well with sensitive detectors; however, in the case of single photons, which are also in a quantum mechanical superposition state, suitable methods did not exist in the nanoworld." In addition, the coupled states of photons and electrons survive for less than a millionth of a millionth of a second and then decay again, leaving hardly any time for their detection.

Part 1

Comment by Dr. Krishna Kumari Challa on February 15, 2023 at 8:51am

Kangaroo fecal microbes could reduce methane from cows

Baby kangaroo feces might help provide an unlikely solution to the environmental problem of cow-produced methane. A microbial culture developed from the kangaroo feces inhibited methane production in a cow stomach simulator in a recent study.

After researchers added the baby kangaroo culture and a known methane inhibitor to the simulated stomach, it produced acetic acid instead of methane. Unlike methane, which cattle discard as flatulence, acetic acid has benefits for cows as it aids muscle growth.

While the researchers have tested their system in the simulated rumen, they hope to try it on real cows  in the future.

 Supriya C. Karekar et al, Reducing methane production from rumen cultures by bioaugmentation with homoacetogenic bacteria, Biocatalysis and Agricultural Biotechnology (2022). DOI: 10.1016/j.bcab.2022.102526

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Reducing the burps and farts of methane emissions from cattle is no laughing matter. Methane is the second largest greenhouse gas contributor and is about 30 times more potent at heating up the atmosphere than carbon dioxide. More than half of the methane released to the atmosphere is thought to come from the agricultural sector, and ruminant animals, such as cattle and goats, are the most significant contributors. Furthermore, the process of producing methane requires as much as 10% of the animal's energy.

Researchers have tried changing cows' diets as well as giving them chemical inhibitors to stop methane production, but the methane-producing bacteria soon become resistant to the chemicals. They also have tried to develop vaccines, but a cow's microbiome depends on where it's eating, and there are far too many varieties of the methane-producing bacteria worldwide. The interventions can also negatively affect the animals' biological processes. 

Comment by Dr. Krishna Kumari Challa on February 15, 2023 at 8:40am

How eyeless centipedes are able to detect sunlight

Researchers have  uncovered the means by which the Chinese red-headed centipede is able to detect sunlight despite having no eyes or even photoreceptors.

Venomous Chinese red-headed centipedes have long, black segmented bodies, yellow legs and a large, eyeless head with long antennae and a mouth capable of biting and injecting venom into prey, predators and humans that happen to step on them. Prior research has shown that the centipede actively avoids sunlight, though it is not known if this is to avoid predators or prevent overheating. Prior research has also shown that in addition to having no eyes, the pencil-size bugs also have no photoreceptors, raising the question of how they know when the sun is shining on them. To find out, the researchers conducted experiments that involved placing specimens in clear containers, some of which were covered with black tape. They then studied how the centipedes moved when exposed to differing amounts of light. They also used thermal cameras to record changes in body temperature during sunlight exposure. They found that the temperature of the antennae rose almost immediately when exposed to sunlight, and did so rapidly. Readings showed temperature increases of up to 9°C within seconds.

To confirm that the antennae were alerting the centipedes to sunlight, the researchers covered the curly red, segmented structures of several specimens and then retested the bugs to see how they responded to sudden bursts of light. The covering made the creatures far less averse to sunlight. The researchers then took a closer look at the antennae to find out how they were working as sunlight heat sensors and found thermal receptors called BRTNaC1 that served as ion channels. They were triggered by temperature increases.

 Zhihao Yao et al, A thermal receptor for nonvisual sunlight detection in myriapods, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2218948120

Comment by Dr. Krishna Kumari Challa on February 14, 2023 at 10:18am

Time of day may determine the amount of fat burned by exercise

Physical activity at the right time of the day seems able to increase fat metabolism, at least in mice. A new study shows that mice that did exercise in an early active phase, which corresponds to morning exercise in humans, increased their metabolism more than mice that did exercise at a time when they usually rest. The results are published in the journal PNAS.

Physical activity at different times of the day can affect the body in different ways since the biological processes depend on the circadian rhythms of the cells. To ascertain how the time of day at which exercise is done affects the burning of fat, researchers studied the adipose tissue of mice after a session of high-intensity exercise performed at two points of the daily cycle, an early active phase and early rest phase (corresponding to a late morning and late evening session, respectively, in humans). The researchers studied various markers for fat metabolism and analyzed which genes were active in adipose tissue after exercise.

Independent of food intake

The researchers found that physical activity at an early active phase increased the expression of genes involved in the breakdown of adipose tissue, thermogenesis (heat production) and mitochondria in the adipose tissue, indicating a higher metabolic rate. These effects were observed only in mice that exercised in the early active phase and were independent of food intake.

These results suggest that late morning exercise could be more effective than late evening exercise in terms of boosting the metabolism and the burning of fat, and if this is the case, they could prove of value to people who are overweight.

The right timing seems to be important to the body's energy balance and to improving the health benefits of exercise. This has to to be ascertained in human beings now.

Pendergrast, Logan A. et al, Time of day determines postexercise metabolism in mouse adipose tissue, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2218510120. doi.org/10.1073/pnas.2218510120

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