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Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 7:05am

The team also underscored how dengue, a pernicious tropical malady, can be understood within the context of other common viral diseases that circle the globe.

The ability of viruses, such as SARS-CoV- 2 and influenza, to continuously change their genetic structure in response to the selective pressure of population immunity complicates control efforts.

In the case of dengue virus, an arbovirus that infects more than 100 million people each year, the situation is even more complex. Individuals with high dengue virus antibody titers are protected from infection and developing severe disease.

However, individuals with sub-neutralizing antibody titers have been shown to have the highest risk of severe disease, through multiple hypothesized mechanisms including antibody-dependent enhancement.

A dengue infection can be tricky. Some patients who have weathered an infection but get infected in a subsequent outbreak can have more severe symptoms the second time around. Yet, most research on repeat dengue infections has regarded each of the serotypes as no different from the other. An assessment of each serotype's genetic differences was needed to provide a clearer picture of potential risks.

To develop that clearer picture, researchers studied each serotype in more than 15,000 patients' infections as a way to peel away much of the mystery surrounding why first-time dengue illnesses are traditionally milder than subsequent ones.

Part 2

Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 6:58am

 Why subsequent bouts of dengue are worse than a first-time infection

A massive upsurge in dengue cases marked by multiple outbreaks is occurring worldwide and raising new questions about who is at elevated risk of severe forms of the mosquito-transmitted disease.

Incidence of the infection has increased by orders of magnitude throughout the so-called dengue belt, which encompasses Central and South America, Sub-Saharan Africa, Southeast Asia and swaths of the South Pacific, home to densely populated islands. Dengue, without question, is the most widespread and rapidly increasing vector-borne disease in the world, according to the World Health Organization.

The story is similar in other dengue-affected areas of the world where lapses in vector control have conspired with global climate change to create an explosion of bloodthirsty mosquitoes, swarms of them moving into regions once considered dengue-free. Only female mosquitoes feed on blood, they're in constant need of the nutrients in it to nurture their eggs.

Now, more than two decades of dengue surveillance  is answering a slew of questions at a time when the world needs guidance most.

Findings from the research have revealed how various subgroups—what virologists call subtypes—of the dengue virus influence future risk of severe infection. It has been known for years that those who become infected in subsequent outbreaks, after a usually mild bout with a first-time infection, are at significant risk of severe disease in later dengue exposures. New research finally has analyzed more than 15,000 cases to discern why that is so.

Writing in Science Translational Medicine, a global team of scientists has explained how the four dengue viral subtypes—DENV-1, 2, 3, and 4—influence the risk of repeated severe infections. The findings provide a new framework for disease monitoring and lay the foundation for vaccination strategies as the new dengue immunizations emerge.

Part 1

Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 6:28am

Researchers approached this problem in many different ways.

In the context of this study, the researchers effectively provided two lines of evidence. The first one is theoretical in essence. Specifically, we rely on so-called Markov Decision Processes (MDPs) to demonstrate that confidence-based control policies are quasi-optimal for a broad class of decisions."

After having identified the non-trivial quantitative properties of confidence-based control policies, the researchers set out to determine whether these properties can be found in empirical data gathered in experiments where humans completed decision-making tasks. The properties they specifically sought for included three-way interactions between the values of different options, decision times and the reported confidence in a decision.

In brief, they identified a minimal cognitive architecture for quasi-optimal decision control (in terms of how much effort is invested). Importantly, this architecture may generalize over most, if not all, kinds of decision types. This implies that a single brain system may operate decision control, irrespective of the type of decision.

 Juliette Bénon et al, The online metacognitive control of decisions, Communications Psychology (2024). DOI: 10.1038/s44271-024-00071-y.

Part 2

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

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