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Comment by Dr. Krishna Kumari Challa on August 7, 2024 at 9:01am

 How our brain decides what to do

 What exactly happens in our brain when we make a decision has been a mystery till now. But researchers  have found the solution. They have deciphered which brain chemical and which nerve cells mediate this decision: the messenger substance orexin and the neurons that produce it.

These neuroscientific fundamentals are relevant because many people don't take good decisions like getting enough exercise because they don't find it easy to decide. Most of us have probably already decided once or even several times to skip exercising in favor of one of the numerous alternative temptations of daily life. According to the World Health Organization, 80% of adolescents and 27% of adults don't get enough exercise. And obesity is increasing at an alarming rate not only among adults but also among children and adolescents.

Despite these statistics, many people manage to resist the constantly present temptations and get enough exercise.

In their experiments with mice, the researchers were able to show that orexin plays a key role in taking decisions. It's one of over a hundred messenger substances that are active in the brain. Other chemical messengers, such as serotonin and dopamine, were discovered a long time ago and their role has largely been decoded. The situation for orexin is different: Researchers discovered it relatively late, around 25 years ago, and they are now clarifying its functions step by step.

In neuroscience, dopamine is a popular explanation till now  for why we choose to do some things but avoid others. This brain messenger is critical for our general motivation. However, our current knowledge about dopamine does not easily explain why we decide to exercise instead of eating. Our brain releases dopamine both when we eat and when we exercise, which does not explain why we choose one over the other.

To find out what does explain this, the researchers devised a sophisticated behavioral experiment for mice, which were able to choose freely from among eight different options in ten-minute trials. These included a wheel they could run on and a "milkshake bar" where they could enjoy a standard strawberry-flavored milkshake.

"Mice like a milkshake for the same reason people do: It contains lots of sugar and fat and tastes good.

In their experiment, the scientists compared different groups of mice: one made up of normal mice and one in which the mice's orexin systems were blocked, either with a drug or through genetic modification of their cells.

The mice with an intact orexin system spent twice as much time on the running wheel and half as much time at the milkshake bar as the mice whose orexin system had been blocked. Interestingly, however, the behavior of the two groups didn't differ in experiments in which the scientists only offered the mice either the running wheel or the milkshake.

This means that the primary role of the orexin system is not to control how much the mice move or how much they eat. Rather, it seems central to making the decision between one and the other, when both options are available. Without orexin, the decision was strongly in favor of the milkshake, and the mice gave up exercising in favour of eating.

researchers expect that orexin may also be responsible for this decision in humans; the brain functions involved here are known to be practically the same in both species.

The researchers are now trying to verify this  in humans too.

Part 1

Comment by Dr. Krishna Kumari Challa on August 7, 2024 at 8:50am

'Cool paint' for cars to keep drivers cooler

Car companies are trying  "cool paint" to keep people inside vehicles cooler, although the coating is six times thicker, making commercialization still a challenge.

The vehicles with the special paint looked like ordinary cars, but felt much cooler to the touch.

The cool paint lowered the cars' roof-panel temperature by 12 degrees Celsius (22 degrees Fahrenheit) and the interiors by 5 C (9 F).

Cooling materials are already widely used in buildings and other items. Cooler cars can reduce use of air-conditioning and relieve the toll from heat on engines and electric vehicle batteries.

They have  also been experimenting with paint that delivers lower cabin temperatures, mostly focusing on colours that refract the sun's rays.

The cool paint reflects sunlight better and also creates electromagnetic waves that block the rays, redirecting energy away from vehicles.

Source: Various news agencies

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 12:01pm

This Super-Black Material Made of Wood Can Absorb 99.3% of Light

A new super-black wood-based material has been created that absorbs more than 99 percent of the light that hits it. 

Researchers were working on water-repelling technologies for wood, using high-energy plasma gas – and noticed that the application of the gas turned the ends of wood cells completely black. Further examination revealed the incredible light absorption properties of the new super-black material.

The researchers  named their new material Nxylon.

Nxylon's composition combines the benefits of natural materials with unique structural features, making it lightweight, stiff and easy to cut into intricate shapes.

The material has a velvety appearance, its inventors report. The plasma treatment actually changes the tiny structures on the surface of the wood, introducing indentations that help to capture light and minimize any reflections.

Indeed, when a gold alloy was applied to the material, it remained black. This shows that the structure of the wood has changed – this isn't just an extra coating, but a reconfiguration of the fundamentals of the material.

Super-black materials are valuable in industries like astronomy, solar energy, and optics, where they help devices function more accurately or efficiently by reducing unwanted light reflection. For example, super-black materials can reduce glare and improve clarity on telescopes.

https://onlinelibrary.wiley.com/doi/10.1002/adsu.202400184

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 9:50am

According to a US national database, cases of liver toxicity linked to botanical use, some severe or even fatal, nearly tripled between 2004 and 2014—from 7% of cases to 20%. Use of turmeric, green tea extract, Garcinia cambodgia were often implicated. Another study found such cases rising from 12.5% of liver toxicity cases in 2007 to 21.1% by 2015.
Who's using these botanicals? According to the new study, the most common consumer is an older (average age about 52) white (75% of users) female (57%), who was typically well-off.

People taking botanicals were more likely to be battling some kind of chronic illness, such as arthritis, thyroid disorders or cancer, compared to folks not using the supplements.
In two-thirds of cases, people took a botanical while also taking a prescription medicine, the study found. Because of the danger of drug interactions and the threat to liver health, it's crucial that botanical users inform their doctors, the research group said.
When botanicals are overused, the damage to the liver "can not only be severe, leading to hepatocellular [liver] injury with jaundice, but also fatal, leading to death or liver transplantation," the research team warned.

A prior study found that the number of liver transplants required due to botanical overuse jumped by 70% between 2009 and 2020.

 Alisa Likhitsup et al, Estimated Exposure to 6 Potentially Hepatotoxic Botanicals in US Adults, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.25822

Part 2

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 9:47am

Excessive use of botanicals like turmeric, green tea are harming  livers

Botanicals like turmeric, green tea and black cohosh may seem benign, but their overuse is being increasingly linked to liver injury.

New research suggests that thousands are using at least one of the several leading botanicals. Many are ending up in hospitals for liver toxicity, researchers report.

Because there's almost no  regulatory oversight over botanicals, chemical tests of products linked to liver crises show frequent discrepancies between product labels and detected ingredients.

The researchers focused on the use of six of the most popular botanicals: Turmeric, green tea extract, the Garcinia cambodgia plant, black cohosh, red yeast rice and ashwagandha.

Millions of adults regularly take turmeric supplements, often with the notion that it can ease pain or arthritis. Unfortunately, "multiple randomized clinical trials have failed to demonstrate any efficacy of turmeric-containing products in osteoarthritis," and overdoing it on turmeric has been linked to serious liver toxicity, the researchers said.

Likewise, millions of  adults are estimated to be taking another potential liver toxin, green tea extract, usually to help boost energy and aid in weight loss.

But again, "multiple studies have failed to demonstrate any objective evidence of weight loss and sustained improvement in mood or energy levels" with products containing the active ingredients in green tea extract, the research  team noted.

Other claims, many unfounded, are made for other botanicals: Garcinia cambodgia is touted for weight loss, black cohosh for easing hot flashes and ashwagandha to help build muscle. But scientists noted that consumers may be overdosing on botanicals, or getting misled by labels that don't reflect the actual ingredients in their supplements. That may be leading to more users ending up in the ER.

Part 1

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 8:51am

Physicists develop new method to combine conventional internet with the quantum internet

Researchers  have developed a new transmitter-receiver concept for transmitting entangled photons over an optical fiber. This breakthrough could enable the next generation of telecommunications technology, the quantum internet, to be routed via optical fibers. The quantum internet promises eavesdropping-proof encryption methods that even future quantum computers cannot decrypt, ensuring the security of critical infrastructure.

In their experiment, the researchers demonstrated that the entanglement of photons is maintained even when they are sent together with a laser pulse. The research results were published in Science Advances.

The physicists could change the colour of a laser pulse with a high-speed electrical signal so that it matches the colour of the entangled photons. This effect enables them to combine laser pulses and entangled photons of the same colour in an optical fiber and separate them again.

This effect could integrate the conventional internet with the quantum internet.

Their experiment shows how the practical implementation of hybrid networks can succeed.

 Philip Rübeling et al, Quantum and coherent signal transmission on a single-frequency channel via the electro-optic serrodyne technique, Science Advances (2024). DOI: 10.1126/sciadv.adn8907

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 8:38am

Sometimes mental effort is associated with unpleasant feelings, study says

If somebody complains that it hurts to think, they may be onto something, as mental exertion appears to be associated with unpleasant feelings in many situations, according to research published in the journal Psychological Bulletin.

Managers often encourage employees, and teachers often encourage students to exert mental effort. On the surface, this seems to work well: Employees and students do often opt for mentally challenging activities. From this, you may be tempted to conclude that employees and students tend to enjoy thinking hard. But the study results suggest that this conclusion would be false: In general, people really dislike mental effort.

Researchers conducted a meta-analysis of 170 studies, published between 2019 and 2020 and comprising 4,670 participants, to examine how people generally experience mental effort. They did so by testing whether mental effort is associated with unpleasant feelings and whether that association depends on the task or the population involved.

The studies used a variety of participants (e.g., health care employees, military employees, amateur athletes, college students) from 29 countries and involved 358 different cognitive tasks (e.g., learning a new technology, finding one's way around an unfamiliar environment, practicing golf swings, playing a virtual reality game).

In all studies analyzed, participants reported the level of effort they exerted as well as the extent to which they experienced unpleasant feelings such as frustration, irritation, stress or annoyance.

Across all populations and tasks, the greater the mental effort, the greater the unpleasantness experienced by participants.

These findings show that mental effort feels unpleasant across a wide range of populations and tasks.

This is important for professionals, such as engineers and educators, to keep in mind when designing tasks, tools, interfaces, apps, materials or instructions. When people are required to exert substantial mental effort, you need to make sure to support or reward them for their effort, say the researchers.

One interesting finding, according to them, was that while the association between mental effort and adverse feelings was still significant, it was less pronounced in studies conducted in Asian countries compared with those in Europe or North America!

This fits with the general idea that the aversiveness of mental effort may depend on people's learning history. High school students in Asian countries tend to spend more time on schoolwork than their European or North American counterparts and may therefore learn to withstand higher levels of mental exertion early on in their lives.

More important is the real-world observation that, despite the aversive nature of mentally challenging tasks, people still voluntarily engage in them.

The Unpleasantness of Thinking: A Meta-Analytic Review of the Association Between Mental Effort and Negative Affect, Psychological Bulletin (2024). DOI: 10.1037/bul0000443

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 8:31am

New biomaterial regrows damaged cartilage in joints

scientists have developed a new bioactive material that successfully regenerated high-quality cartilage in the knee joints of a large-animal model.

Although it looks like a rubbery goo, the material is actually a complex network of molecular components, which work together to mimic cartilage's natural environment in the body.

In the new study, the researchers applied the material to damaged cartilage in the animals' knee joints. Within just six months, the researchers observed evidence of enhanced repair, including the growth of new cartilage containing the natural biopolymers (collagen II and proteoglycans), which enable pain-free mechanical resilience in joints.

Stupp, Samuel I., A bioactive supramolecular and covalent polymer scaffold for cartilage repair in a sheep model, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2405454121

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 8:25am

Streetlights running all night makes leaves so tough that insects can't eat them, threatening the food chain

Light pollution disrupts circadian rhythms and ecosystems worldwide—but for plants, dependent on light for photosynthesis, its effects could be profound. Now scientists writing in Frontiers in Plant Science have found that exposure to high levels of artificial light at night makes tree leaves grow tougher and harder for insects to eat, threatening urban food chains.

Compared to natural ecosystems, tree leaves in most urban ecosystems generally show little sign of insect damage. Scientists were curious as to why. Their observations show that   in two of the most common tree species in Beijing, artificial light at night led to increased leaf toughness and decreased levels of leaf herbivory.

Artificial light has increased levels of night-time brightness by almost 10%: most of the world's population experiences light pollution every night. Because plant properties affect their interactions with other plants and animals, any changes to plants caused by artificial light could have a significant impact on the ecosystem.

Leaves that are free of insect damage may bring comfort to people, but not insects. Herbivory is a natural ecological process that maintains the biodiversity of insects.

The scientists suspected that plants experiencing high levels of artificial light would focus on defense rather than growth, producing tougher leaves with more chemical defense compounds. 

In their experiments,  they  found that the more intense the light, the more frequently they encountered leaves that showed no signs at all of herbivory.

It is possible that trees exposed to artificial light at night may extend their photosynthesis duration. Additionally, these leaves might allocate a greater proportion of resources to structural compounds, such as fibers, which could lead to an increase in leaf toughness.

Lower levels of herbivory imply lower abundances of herbivorous insects, which could in turn result in lower abundances of predatory insects, insect-eating birds, and so on. 

If there 're less pollinating insects, that would also affect the fruit yield.

 Artificial light at night decreases leaf herbivory in typical urban areas, Frontiers in Plant Science (2024). DOI: 10.3389/fpls.2024.1392262

Comment by Dr. Krishna Kumari Challa on August 6, 2024 at 8:10am

Researchers use vibrations from traffic to measure underground soil moisture

Researchers have developed a new method to measure soil moisture in the shallow subterranean region between the surface and underground aquifers. This region, called the vadose zone, is crucial for plants and crops to obtain water through their roots.

However, measuring how this underground moisture fluctuates over time and between geographical regions has traditionally relied on satellite imaging, which only gives low-resolution averages and cannot penetrate below the surface. Additionally, moisture within the vadose zone changes rapidly—a thunderstorm can saturate a region that dries out a few days later.

The new method relies upon seismic technology that normally measures how the ground shakes during earthquakes. However, it can also detect the vibrations of human activity, like traffic. As these vibrations pass through the ground, they are slowed down by the presence of water—the more moisture, the slower the vibration moves. The new study measures the water content in the vadose zone through seismic rumblings from everyday traffic.

The new method is based on a technique pioneered in the  lab, called distributed acoustic sensing (DAS). With this technique, lasers are pointed into unused underground fiber-optic cables (like the kind that provides the internet).

As a seismic wave, or any kind of vibration, passes through the cable, the laser light bends and refracts. Measuring the wiggles in this laser light gives researchers information about the passing wave, making the 10-kilometer cable equivalent to a line of thousands of conventional seismic sensors.

The ability to measure vadose zone moisture in real time is crucial for managing water use and conservation efforts. 

Fiber-optic seismic sensing of vadose zone soil moisture dynamics, Nature Communications (2024).

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