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Comment by Dr. Krishna Kumari Challa on June 5, 2024 at 10:29am

Researchers identify first step in allergic reactions, paving the way for preventative strategies

Scientists  have identified how the first domino falls after a person encounters an allergen, such as peanuts, shellfish, pollen or dust mites. Their discovery, published in the journal Nature Immunology, could herald the development of drugs to prevent these severe reactions.

It is well established that when mast cells, a type of immune cell, mistake a harmless substance, such as peanuts or dust mites, as a threat, they release an immediate first wave of bioactive chemicals against the perceived threat. When mast cells, which reside under the skin, around blood vessels and in the linings of the airways and the gastrointestinal tract, simultaneously release their pre-stored load of bioactive chemicals into the blood, instant and systemic shock can result, which can be lethal without quick intervention.

More than 10% of the global population suffers from food allergies, according to the World Health Organization (WHO). As allergy rates continue to climb, so does the incidence of food-triggered anaphylaxis and asthma worldwide.

What the researchers have now discovered is that the release of particulate mast cell granules, which contain these bioactive chemicals, is controlled by two members of an intracellular multiprotein complex called inflammasome. Until now, these inflammasome proteins were only known to spontaneously assemble within immune cells to secrete soluble chemicals to alert other parts of the immune system upon detection of an infection.

They discovered that the inflammasome components played a surprisingly crucial role in transporting particulate mast cell granules which are typically packed in the cell center to the cell surface where they are released. This surprising discovery gives us a precise target where we can intervene to prevent the cascade of events initiated in mast cells that leads to anaphylactic shock.

Andrea Mencarelli et al, Anaphylactic degranulation by mast cells requires the mobilization of inflammasome components, Nature Immunology (2024). DOI: 10.1038/s41590-024-01788-y

Comment by Dr. Krishna Kumari Challa on June 5, 2024 at 10:22am

Doctors develop minimally invasive procedure to avoid drilling a 'burr hole' in the skull to treat clot on the brain

In 2018, a New York surgeon-scientist and his team demonstrated in a proof-of-concept study that a minimally invasive procedure could effectively treat one of the world's most common conditions requiring neurosurgical intervention.

The condition is called chronic subdural hematoma, an accumulation of blood and blood breakdown products on the brain's surface just beneath the dura, the brain's protective covering. The mass is caused by damaged vessels that chronically leak blood between the brain and the dura. Risk factors for the abnormality, which can reach significant size, include older age; untreated head trauma; long-term use of blood thinning agents, such as warfarin, or extensive time on anti-inflammatory drugs, like ibuprofen.

Now doctors at Stony Brook Medicine report that not only is the new method of alleviating chronic subdural hematoma effective, it's destined to replace the invasive old-school surgery to remove the accumulation of blood.

The new method of treatment is called middle meningeal artery embolization—MMAE—which relies on an injectable fluid to plug the leakage. Studies conducted around the world show that it's safe, effective and eliminates the risks of surgery. Research at Stony Brook led to a global study of the procedure, and doctors have now demonstrated that the new method not only stops the leakage, it forces the hematoma into permanent retreat.

The standard of care for decades has been surgery, which was designed to provide drainage by drilling a burr hole into the skull or performing a craniotomy, the surgical removal of a portion of the skull to release accumulated blood. While these procedures can alleviate the mass, a chronic subdural hematoma can recur despite the highly invasive attempt to eliminate it. The recurrence rate runs as high as 20%, studies have shown.

Worse, surgery is often poorly tolerated by a broad population of patients.

Chronic subdural hematoma as an insidious condition, developing slowly, often over weeks to months. The mass can put pressure on the brain causing a range of symptoms: slurred speech, forgetfulness, impaired motor function, even coma.

The new approach uses a specialized fluid that is injected into the middle meningeal arteries through a micro-catheter. The liquid embolic agent blocks—embolizes—the abnormal blood vessels that are responsible for the chronic leakage of blood onto the brain's surface. The liquid embolic agent solidifies once it enters the vasculature. Doctors view each step of the procedure via imaging technology.

The enormous potential of a minimally invasive procedure that is safe and effective has captured the attention of neurosurgeons around the world.

David Fiorella et al, Middle meningeal artery embolization for the management of chronic subdural hematoma: what a difference a few years make, Journal of NeuroInterventional Surgery (2023). DOI: 10.1136/jnis-2023-020498

Arindam Rano Chatterjee, Invited Commentary: A New Era in the Treatment of Chronic Subdural Hematomas, RadioGraphics (2024). DOI: 10.1148/rg.240038

Comment by Dr. Krishna Kumari Challa on June 4, 2024 at 10:41am

Greener, more effective termite control: Natural compound attracts wood eaters

Scientists have discovered a highly effective, nontoxic, and less expensive way to lure hungry termites to their doom.

The method, detailed in the Journal of Economic Entomology, uses a pleasant-smelling chemical released by forest trees called pinene that reminds western drywood termites of their food. They follow the scent to a spot of insecticide injected into wood.

Researchers saw significant differences in the death rates using insecticide alone versus the insecticide plus pinene. Without pinene, they got about 70% mortality. When they added it in, it was over 95%.

Fumigation is one of the most common drywood termite control techniques. Homes are covered with tents and then bombed with gas that kills the insects.

The pest control industry is under pressure to find new methods because the chemical, sulfuryl fluoride, is both a greenhouse gas and is also toxic to humans. Additionally, fumigation is an expensive process that does not provide lasting protection against termites.

Even though it is very thorough, a home can be infested again soon after fumigation is completed. Some people fumigate every three to five years because it doesn't protect structures from future infestations.

Localized injection is an alternative strategy to control drywood termites that does not involve gas. Technicians drill holes into the infested wood to reach the termite "gallery" or lair, then inject poison into the hole to inundate the bugs.

This is a more localized treatment, and in theory, it is a better strategy when you want to control drywood termites with fewer chemicals. It's less expensive, and the treated wood may also stay protected from future infestations.

The challenge with localized injection is figuring out exactly where the bugs are hiding. Typically, this method uses a contact-based insecticide, meaning the insects must touch the poison for it to work.

Using an attractant like pinene eliminates the need to hunt for the termites. Even at low concentrations, pinene is good at attracting termites from a distance.

 Nicholas A Poulos et al, Potential use of pinenes to improve localized insecticide injections targeting the western drywood termite (Blattodea: Kalotermitidae), Journal of Economic Entomology (2024). DOI: 10.1093/jee/toae101

Comment by Dr. Krishna Kumari Challa on June 4, 2024 at 9:23am

Study sheds new light on the contribution of dopamine to reinforcement learning

The neurotransmitter dopamine has often been linked to pleasure-seeking behaviors and making stimuli paired with rewards  valuable. Nonetheless, the processes through which this key chemical messenger contributes to learning have not yet been fully elucidated.

Researchers carried out a study now aimed at better understanding how dopaminergic neurons (i.e., brain cells supporting the production of dopamine) support reward-based learning. Their findings, published in Nature Neuroscience, suggest that rather than representing the value attributed to different stimuli, these neurons contribute to the formation of new mental associations between stimuli and reward (or other neutral stimuli), which help us form cognitive maps of our environment.

This recent research has shown that firing of dopamine neurons act as the brain's teaching signal. This occurs whenever something new or salient happens, which helps us learn to associate events together to make a new memory. Critically, this work has shown that dopamine neurons do this without making things 'valuable' or 'good' in and of themselves.

This work is at odds with past studies that have defined dopamine as the neurotransmitter producing "happiness" or "pleasure." However, if dopaminergic neurons do not carry value signals, they should be unable to attribute positive or pleasurable qualities to specific experiences or actions.

The results of their experiment suggest that when dopamine neurons fire in everyday life, they're not making things valuable. Instead, they function to help us form new memories or how things in our environment are related. In a case where dopamine neurons fire more than they are supposed to (e.g., when taking drugs of abuse), this may be encoded in the brain as a rewarding event that makes us more likely to seek out drugs in future.

Overall, this recent study by researchers could greatly contribute to the understanding of dopamine and its role in reward-based (i.e., reinforcement) learning. In particular, their findings suggest that dopamine neurons do not carry value signals that attach pleasure or happiness to stimuli in the environment.

The researchers are now interested in finding how different dopamine circuits contribute to different types of learning and how this helps us to create a complex but unified representation of our environment.

Samuel J. Millard et al, Cognitive representations of intracranial self-stimulation of midbrain dopamine neurons depend on stimulation frequency, Nature Neuroscience (2024). DOI: 10.1038/s41593-024-01643-1

Comment by Dr. Krishna Kumari Challa on June 4, 2024 at 7:05am

Comment by Dr. Krishna Kumari Challa on June 3, 2024 at 6:53am

Study Suggests Young Children Trust Robots Over Humans!

Many of us will be familiar with tales of kids befriending robots, which suggest generations of young children are more trusting of advice from machines than their own flesh and blood. An international research team has now found it's not just in fiction. In a study involving 111 kids aged between 3 and 6 years old, the youngsters showed a preference for believing robots more and being more accepting when robots made mistakes.
Where both humans and robots were shown to be equally reliable in the experiments, the youngsters were more likely to want to ask robots the names of new objects and accept their labels as accurate. What's more, the children were more likely to favor robots when asked about who they would share secrets with, who they would want to be friends with, and who they would want to have as teachers.
Children's conceptualizations of the agents making a mistake also differed, such that an unreliable human was selected as doing things on purpose, but not an unreliable robot.
These findings suggest that children's perceptions of a robot's reliability are separate from their evaluation of its desirability as a social interaction partner and its perceived agency."

There were individual differences in the responses: older kids were more trusting of humans than younger kids, but only when the robot was shown to be unreliable compared to the human. Taken as a whole though, the results showed these children thought reliable robots were more trustworthy than reliable humans.

One area where this research might be useful is in education, especially in a world where kids are increasingly surrounded by technology.

The researchers didn't ask anything about why these children felt that the robots they met could be trusted more than people.

https://www.sciencedirect.com/science/article/pii/S0747563224000979

Comment by Dr. Krishna Kumari Challa on June 2, 2024 at 1:05pm

From a purely technical point of view, sound in the air cannot be more intense than 194 dB. At this intensity, the individual sound waves interfere with each other and create a vacuum. Of course, it is possible to go beyond this limit, but we should talk more about a shock wave instead of a sound wave then.

Earthquakes are hardly ever associated with a loud noise, but the opposite is true. The most intense is submarine earthquakes. Even those registered 5.0 on the Richter scale reach a noise intensity of 235 dB in water.

Tunguska Meteorite Explosion

What happened on this otherwise peaceful 1908 morning in Russia? In addition to the explosion of a space asteroid high above Earth, we could probably also experience the second-noisiest one-off show on Earth. The power of the noise was estimated at 300 dB. If we wanted to create a similar sound wave with an atomic bomb, we would need a bomb about 50 times stronger than the largest we have ever made and detonated.

 Krakatoa Volcano Eruption

The intensity of a shock wave at the top of our list can only be estimated by calculation. Although the Tunguska meteorite explosion later came as a strong opponent, the winner was the eruption of the Krakatoa volcano in 1883. It was clearly heard even at a distance of 5,000 km, and the sound waves the blast had caused circled the Earth four times in all directions. At a distance of 160 km, noise intensities as loud as 172 dB were recorded, so it could be calculated that the noise in the epicentre must have been as high as hard-to-be-imagined 310 dB.

How loud can something be?

Once you get to a certain level (194 decibels, to be precise), there comes a point where the low-pressure regions are completely empty – there are no molecules in there at all. The sound can’t get ‘louder’ than that, technically. If there is more energy in the noise source, the air molecules are just pushed along wholesale, rather than moving back and forth, and the soundwave has turned into a shockwave.

The shockwave from Krakatoa was so strong it circled the Earth four times.

Comment by Dr. Krishna Kumari Challa on June 1, 2024 at 12:21pm

But the question was: Can you add yet another proton to the hydronium ion to fill in the missing piece? Such a configuration at normal conditions is energetically very unfavorable, but scientists' calculations show there are two things that can make it happen.
First, very high pressure compels matter to reduce its volume, and sharing a previously unused electron pair of oxygen with a hydrogen ion (proton) is a neat way of doing that: like a covalent bond with hydrogen, except both electrons in the pair come from oxygen. Second, you need lots of available protons, and that means an acidic environment, because that's what acids do—they donate protons.
The team used advanced computational tools to predict what happens to hydrofluoric acid and water under extreme conditions. The result: Given a pressure of about 1.5 million atmospheres and a temperature around 3,000 degrees Celsius, well-separated aquodiium H4O2+ ions turn up in the simulation.

The scientists think that their newly discovered ion should play an important role in the behavior and properties of water-based media, specifically those under pressure and containing acid.

This roughly corresponds to conditions on Uranus and Neptune, where an immensely deep liquid water ocean produces extremely high pressures and some amount of acid might be expected, too. If so, aquodiium ions will form and by participating in the ocean's circulation, will contribute to these planets' magnetic fields and other properties in ways distinct from other ions.
Perhaps, aquodiium might even form as yet unknown minerals under those extreme conditions.

ingyu Hou et al, H₄O²⁺ ion stabilized by pressure, Physical Review B (2024). DOI: 10.1103/PhysRevB.109.174102

Part 3

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Comment by Dr. Krishna Kumari Challa on June 1, 2024 at 12:18pm

In chemistry, there's the notion of sp3 hybridization, which refers to the way electron orbitals combine with each other and amounts to something like a natural template for making plausible molecules and ions. Under sp3 hybridization, the nucleus of an atom—e.g., carbon, nitrogen, or oxygen—occupies the center point of an imaginary tetrahedron.

Each of the four vertices hosts either a valence electron or two paired electrons that are not available for making bonds with other atoms. The simplest example would be a carbon atom with four unpaired electrons at the four vertices—add four hydrogen atoms and you get a methane molecule: CH4.

For an oxygen atom, which has two electron pairs of its own in the outermost shell, along with two valence electrons, sp3 hybridization would mean only two of the vertices could host a covalent bond with hydrogen, with the remaining two occupied by electron pairs, which yields H2O, water.

If you attach a hydrogen ion (a proton) to one of the electron pairs, you get a hydronium ion H3O+, and this is actually what you get in an acid solution, because acids donate protons H+ into the solution and lone protons are immediately drawn to electron pairs.
Part 2

Comment by Dr. Krishna Kumari Challa on June 1, 2024 at 12:18pm

An outlandish molecule may be lurking inside Uranus and Neptune, affecting their magnetic fields

Scientists  have determined the conditions that enable the existence of a very peculiar ion. Dubbed aquodiium, it can be conceptualized as an ordinary neutral molecule of water with two additional protons stuck to it, resulting in a net double positive charge.

They  suggest that the ion could be stable in the interior of the ice giants Uranus and Neptune, and if so, it must play a part in the mechanism that gives rise to these planets' unusual magnetic fields. The study is published in Physical Review B

The magnetic fields of Uranus and Neptune are not understood quite as well as those of Jupiter and Saturn—or our own planet, for that matter.

In the Earth's interior, circulation of the electronically conductive liquid iron-nickel alloy produces magnetism. Deep inside Jupiter and Saturn, hydrogen is thought to be pressed into a metallic state and give rise to magnetic fields in much the same way.

By contrast, the magnetic fields of Uranus and Neptune are hypothesized to stem from the circulation of ionically conductive media, where the constituent ions are themselves charge carriers, rather than merely a support structure enabling the flow of electrons.

If planetary scientists knew exactly what ions and in which proportions are involved, perhaps they could figure out why the ice giants' magnetospheres are so quirky: misaligned with the direction of the planets' rotation and offset from their physical centers.

They explain how ionic and electronic conductivity are different and where the newly predicted ion fits into this: The hydrogen surrounding Jupiter's rocky core at those conditions is a liquid metal: It can flow, the way molten iron in the Earth's interior flows, and its electrical conductivity is due to the free electrons shared by all the hydrogen atoms pressed together.

In Uranus, they think that hydrogen ions themselves—i.e., protons—are the free charge carriers. Not necessarily as standalone H⁺ ions, but perhaps in the form of hydronium H₃O⁺, ammonium NH₄⁺, and a series of other ions. This new study adds one more possibility, the H₄O²⁺ ion, which is extremely interesting from the chemical viewpoint."

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