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Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 6:22am

A minimal cognitive architecture reproduces control of human decision-making processes

Neuroscientists and psychologists have been trying to pinpoint the processes behind human decision-making for decades. While their efforts led to numerous interesting insights, the intricacies of complex decision-making remain poorly understood.

Researchers at the Paris Brain Institute carried out a study aimed at better understanding how the human brain allocates its resources when making decisions. Their paper, published in Communications Psychology, introduces an architecture that operates the online metacognitive control of decisions (oMCD), a theoretical construct describing why and how the brain choses to stop of continue deliberating.

Past studies have found that humans do not always invest their maximum mental efforts when making decisions. This can lead to various widely documented errors and cognitive biases (i.e., recurring deviations from rational thinking).

So when making a decision, what determines the amount of mental effort we invest in decisions?

Previous behavioral research suggested that, for certain kinds of decisions (so-called 'evidence-based' decisions), this may be done by balancing decision confidence (which tends to increase with mental effort) with the cost of mental effort. This then triggered the question: can this work for all kinds of decisions?

To address this question, researchers should first demonstrate that a confidence-based control policy eventually yields mental effort investments resembling those of optimal control policies that are specific to different kinds of decisions. This was one of the primary objectives of this work.

Part 1

Comment by Dr. Krishna Kumari Challa on May 14, 2024 at 12:34pm

This New Plastic Disappears When You Don't Need It Anymore

The plastic that eats itself

Our reliance on plastic has become a huge problem, which is why researchers are excited about a new type of material – one that comes with built-in biodegrading capabilities, due to the bacterial spores living inside it. The new self-digesting plastic combines thermoplastic polyurethane (TPU) and Bacillus subtilis bacteria, which had to be engineered to survive the high temperatures involved in plastic production. By repeatedly exposing the spores to increasing levels of heat, the team of researchers behind this new work found that the bacteria could eventually cope with the temperatures of 135 degrees Celsius (275 degrees Fahrenheit) required to mix the bacterial spores and TPU together. Past efforts to find ways to degrade plastics, fast, have often sourced bacterial enzymes and fungi from soils and compost heaps where those microbes are naturally abundant. But this new material needs only the bacterial spores inside it, reawakened with some nutrients and moisture, to start breaking down.

https://www.nature.com/articles/s41467-024-47132-8

Comment by Dr. Krishna Kumari Challa on May 14, 2024 at 10:34am

Greenhouse gas emissions from using basic stoves and deforestation from collecting wood also contribute hugely to global warming.

Switching to clean cooking methods, such as LPG or electric cooking, would save 1.5 billion tonnes of CO₂ a year by 2030—roughly the amount emitted by ships and planes last year, according to the IEA.

IEA also recommends strong national leadership as well as grassroots efforts to change social norms.

Source: AFP and other news agencies

Comment by Dr. Krishna Kumari Challa on May 14, 2024 at 10:33am

Bid to end deadly cooking methods which stoke global warming

Fifty countries are meeting in France  today to discuss the lack of access to clean cooking methods worldwide which causes millions of deaths every year and fuels global warming.

Some 2.3 billion people across 128 countries breathe in harmful smoke when they cook on basic stoves or over open fires, according to an International Energy Agency (IEA)-African Development Bank (ADB) report that sounded the alarm last year.

It said 3.7 million people a year die prematurely from harmful cooking practices, with children and women most at risk.

The IEA said the "unprecedented" Paris gathering aims to be "a moment of changing the direction". The problem "touches on gender, it touches on forestry, it touches on climate change, it touches on energy, it touches on health.

A third of the world cooks with fuels which produce harmful fumes when burned, including wood, charcoal, coal, animal dung and agricultural waste.

They pollute indoor and outdoor air with fine particles that penetrate the lungs and cause multiple respiratory and cardiovascular problems, including cancer and strokes.

These cooking practices are the third highest cause of premature deaths in the world and the second highest in Africa. In young children , they are a major cause of pneumonia, experts say.

They also prevent women and children from accessing education or earning a wage, as they spend hours looking for fuel.

Part 1

Comment by Dr. Krishna Kumari Challa on May 14, 2024 at 9:53am

 Augmented Reality Contact Lens!

Mojo Lens, an in-development contact lens with an embedded augmented reality display and the electronics needed to run it wirelessly. With a tethered prototype held up to our eye, we could clearly see how the .5mm wide microLED shows images and text as well as a user interface that can be controlled with literal eye tracking. Here's how the Mojo system works and exactly what hardware is packed inside this smart contact lens!

Comment by Dr. Krishna Kumari Challa on May 14, 2024 at 9:31am

Evidence of a travel direction signal that is independent from head direction in humans

We generally assume that when humans are walking or otherwise moving in space, their head faces towards the direction they are traveling in. Nonetheless, travel direction and head direction are distinct factors associated with the processing of different types of spatial information.

Researchers recently unveiled a travel direction-related signal represented in the human mind that appears to be independent from head direction. Their paper, published in the Journal of Experimental Psychology: General, could soon open new avenues for neuroscience and psychology research focusing on spatial navigation.

Finding your way can be complicated, but in some ways keeping track of your position requires a few basic pieces of information—your speed, how long you have been going, what direction you are going in. 

Head direction and travel direction have been found to provide very different information. Overall, travel direction plays a greater role than head direction in shaping the trajectory that humans or animals will follow while moving in their surrounding environment.

Moreover, studies found that people's heads are not always facing the direction they are going in.

Researchers carried out a behavioral experiment aimed at searching for a travel direction signal that is entirely separate from head direction.

This recent study ( and its results) was the first to hint at the existence of a signal of travel direction in humans that is independent from head direction. The findings it gathered prompt interesting new questions about the unique contributions of travel direction to spatial navigation.

 You Cheng et al, (Don't) look where you are going: Evidence for a travel direction signal in humans that is independent of head direction., Journal of Experimental Psychology: General (2024). DOI: 10.1037/xge0001538.

Comment by Dr. Krishna Kumari Challa on May 13, 2024 at 11:22am

Some Snakes Fake Their Own Deaths, And They Even Use Special Effects!

Playing dead is a common defense strategy in the animal kingdom, but some especially melodramatic snakes have now been seen dialing it up to 11. In addition to flopping inert, mouths agape, dice snakes (Natrix tessellata) add some amazingly gross special effects. They'll defecate and smear themselves in feces, excrete stinky musk, and even start bleeding from the mouth, for what might be the most realistic deaths ever feigned in nature.

Scientists studying these top-tier acting skills found that adding a little something more allows the snake to escape more quickly, evading predation more adroitly than snakes that don't go the extra mile.

A behaviour known as apparent death – or tonic immobility – is actually quite common in nature, across a wide range of taxa. Its ubiquity suggests that it's an effective defense against predators, although exactly why is unclear. Some research suggests that it's often a last-ditch effort to escape after predator-prey contact has already occurred.

it works, some snakes seem to have found a way to tip the odds even further in their favor. Eastern hog-nosed snakes (Heterodon platirhinos), for example, flip onto their backs, convulse, puke, and excrete musk. This is a foul-smelling substance produced in glands near the snake's cloaca, like the anal glands of skunks.

Dice snakes – a non-venomous species that mainly eats fish – are known to have feces and musk among in their defensive toolkit; when alarmed, they struggle, hiss, and coat themselves in stench. They also play dead, and have been seen bleeding from the mouth using an ability known as autohemorrhaging.

These snakes are considered as tasty  to quite a number of predators, including reptiles, birds, and mammals.

https://royalsocietypublishing.org/doi/10.1098/rsbl.2024.0058

Comment by Dr. Krishna Kumari Challa on May 13, 2024 at 9:26am

Their findings support previous studies that led scientists to suspect that the smaller the plastic fragment, the more likely it is to penetrate deeper into the lung, possibly infiltrating the alveolar sacs where crucial gas exchange occurs.

It's not just degraded plastic products, like drink bottles, that are causing this threat, either. Common cosmetic products, like gritty toothpaste, are made purposefully with these tiny fragments. Some reports estimate that in India, toothpaste is responsible for emitting 1.4 billion grams of microplastic particles each year.

When breathed in, experimental evidence strongly suggests that such tiny plastics have the capacity to trigger inflammation, oxidative stress, lung tissue damage, or systemic dysfunction in the respiratory tract. So far, however, research on the potential health outcomes of microplastics is mostly confined to animal models and human cells.
One recent exception was a study among surgery patients, which found that those who had more plastic in a main artery of their body had a higher chance of heart attack, stroke, or death in the following years. Given the ramifications, associations between cardiac health and plastic pollutants needs to be further explored.

"Plastic particle air pollution is now pervasive and inhalation ranks as the second most likely pathway for human exposure.
For the health of humans everywhere, it is crucial that toxicologists fully understand where these ubiquitous particles are going when we breathe them in and what they are doing to our bodies.
Part 2

Comment by Dr. Krishna Kumari Challa on May 13, 2024 at 9:25am

How Far Can Plastic  Reach Into Your Lungs?

Miniscule fragments of plastic pollution invade the human body every day without our knowing it, not just from eating and drinking but from simply breathing.
By some estimates, the average person inhales a credit card's worth of plastic every week with unknown health effects. In 2022, scientists found microplastics hiding in the deepest parts of the human lung for the first time.
The worldwide spread of plastic has not only crept up on us, it has crept up in us, and scientists are now rushing to figure out where these pollutants go when we breathe them in, how long they stick around for, and if they have toxic effects.

Researchers at the University of Technology Sydney (UTS) have now tracked the passage of plastic as it flows through the respiratory system. Their model builds on a pioneering attempt in 2023 to identify hotspots where microplastics and nanoplastics might gather in our airways.

That prior study focused mostly on modeling the upper airway tract, but the new study considers how air and particles flow through the entire tract, "from the nasal cavity down to the 13th generation of the bronchial tree".

It also models three different breathing rates – slow, medium, and fast – and three different sizes of plastic fragments; large microplastics, microplastics, and nanoplastics.

The result is a delicate balance, the researchers say, between the way that gravity drags plastics onto a surface and the way that wind blows them along a passageway.
At a normal breathing rate, the model suggests microplastics in the air can come to cover half the surface area of a nasal cavity. At slower breathing rates, medium-sized pollutants were largely deposited in the upper airway, including the nasal cavity, the voice box, and the junction where the windpipe connects to the throat. Meanwhile, smaller, dust-like particles were distributed more evenly throughout the upper and lower respiratory tract.
Larger microplastics displayed a tendency for rapid deposition in the upper airways, whereas smaller nanoplastics exhibited a higher likelihood of escape or reaching deeper airway generations," the researchers conclude.

https://www.sciencedirect.com/science/article/pii/S2666765724000437...

Part 1

Comment by Dr. Krishna Kumari Challa on May 11, 2024 at 12:52pm

GoT-ChA: New tool reveals how gene mutations affect cells

A team co-led by researchers at Weill Cornell Medicine and the New York Genome Center has developed an advanced method for revealing how gene mutations disrupt the normal packaging of DNA. These structural changes, which alter patterns of gene activity in a cell, are known as epigenetic changes and can lead to malignancy.

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Why evolution often favors small animals and other organisms

Small really does seem to be beautiful in evolutionary terms. The largest dinosaurs, pterosaurs and mammals may look impressive but these giants are vastly outnumbered by microscopic bacteria and single-celled algae and fungi. Small organisms are also ancient and incredibly resilient.

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