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Comment by Dr. Krishna Kumari Challa 9 hours ago

What are nanoplastics? Concern is growing about particles too small to see

It's become common to read/hear that microplastics—little bits of plastic, smaller than a pencil eraser—are turning up everywhere and in everything, including the ocean, farmland, food and human bodies. Now a new term is gaining attention: nanoplastics. These particles are even tinier than microplastics—so small that they're invisible to the naked eye.

Nanoplastics are a type of microplastic, distinguished by their extremely small size. Microplastics are usually less than 5 millimeters across; nanoplastics are between 1 and 1,000 nanometers across. For comparison, an average human hair is roughly 80,000–100,000 nanometers wide.

Nanoplastics are attracting growing concern thanks to recent technological advances that have made researchers more able to detect and analyze them. Their smaller size means that they are more easily transported over long distances and into more diverse environments than microplastics. They can more easily penetrate cells and tissues in living organisms, which could lead to different and more acute toxicological effects.

Studies in the past two years have found nanoplastics in human blood, in liver and lung cells, and in reproductive tissues such as the placenta and the testes. Around the world, nanoplastics have been found in the air, in seawater, in snow and in soil.
We already know that microplastics are present from the heights of Mount Everest to deep ocean trenches. Now there is growing evidence that nanoplastics are more prevalent than larger microplastics in the environment.

Comment by Dr. Krishna Kumari Challa 11 hours ago

Researchers show that slow-moving earthquakes are controlled by rock permeability

Earthquakes are the most dramatic and noteworthy results of tectonic plate movement. They are often destructive and deadly, or at the very least physically felt—they're literally groundbreaking geological events. However not all tectonic movement results in effects that humans can perceive.

Slow slip events occur when pent up tectonic forces are released over the course of a few days or months, like an earthquake unfolding in slow motion. The more gradual movement means people won't feel the earth shaking beneath their feet and buildings won't collapse. But the lack of destruction does not make slow slip events less scientifically important. In fact, their role in the earthquake cycle may help lead to a better model to predict when earthquakes happen.

In a paper published recently in Geophysical Research Letters, a Jackson School of Geosciences research group explores how the makeup of rocks, specifically their permeability—or how easily fluids can flow through them—affects the frequency and intensity of slow slip events.

Their tests showed how pores in the rocks could control the regular slow slip events at this subduction zone. Previous studies have suggested that a layer of impermeable rock at the top of the descending tectonic plate serves as a sealed lid, trapping fluid in the pores of underlying rock layers.

As fluid accumulates beneath the seal, the pressure builds, eventually becoming high enough to trigger a slow slip event or earthquake. This event then breaks the impermeable seal, temporarily fracturing the rocks, allowing them to soak up fluids. Within a few months, the rocks heal and return to their initial permeability, and the cycle starts all over again.

In this work,  for the first time, the researchers showed that using rocks that are representative of those at depth, that permeability is controlling slow slip events.

Nicola Tisato et al, Permeability and Elastic Properties of Rocks From the Northern Hikurangi Margin: Implications for Slow‐Slip Events, Geophysical Research Letters (2024). DOI: 10.1029/2023GL103696

Comment by Dr. Krishna Kumari Challa 11 hours ago

Research team discovers new property of light

A research team headed by chemists  has discovered a previously unknown way in which light interacts with matter, a finding that could lead to improved solar power systems, light-emitting diodes, semiconductor lasers and other technological advancements.

 In a paper published recently in the journal ACS Nano, the scientists explain how they learned that photons can obtain substantial momentum, similar to that of electrons in solid materials, when confined to nanometer-scale spaces in silicon.

Silicon is Earth's second-most abundant element, and it forms the backbone of modern electronics. However, being an indirect semiconductor, its utilization in optoelectronics has been hindered by poor optical properties.

While silicon does not naturally emit light in its bulk form, porous and nanostructured silicon can produce detectable light after being exposed to visible radiation. Scientists have been aware of this phenomenon for decades, but the precise origins of the illumination have been the subject of debate.

In 1923, Arthur Compton discovered that gamma photons possessed sufficient momentum to strongly interact with free or bound electrons. This helped prove that light had both wave and particle properties, a finding that led to Compton receiving the Nobel Prize in physics in 1927.

In the present  experiments, researchers showed that the momentum of visible light confined to nanoscale silicon crystals produces a similar optical interaction in semiconductors.

This discovery of photon momentum in disordered silicon is due to a form of electronic Raman scattering. But unlike conventional vibrational Raman, electronic Raman involves different initial and final states for the electron, a phenomenon previously only observed in metals.

Sergey S. Kharintsev et al, Photon-Momentum-Enabled Electronic Raman Scattering in Silicon Glass, ACS Nano (2024). DOI: 10.1021/acsnano.3c12666

Comment by Dr. Krishna Kumari Challa 11 hours ago

Adoption may be a lot easier to accept than infanticide, but it's actually more difficult to understand because it challenges Darwin's ideas about natural selection. It 's very interesting to see that the reproductive fitness outcomes 're about even between adoption and infanticide and suggests that they have an alternative strategy—adoption may be a non-violent means of getting genes into the next generation.

Steven R. Beissinger et al, Eviction-driven infanticide and sexually selected adoption and infanticide in a neotropical parrot, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2317305121

Part 2

Comment by Dr. Krishna Kumari Challa 11 hours ago

Why parrots sometimes adopt—or kill—each other's babies

Infanticide and adoption in the animal kingdom have long puzzled scientists. While both males and females of many species are known to kill the babies of their rivals to secure sexual or social advantage, other animals have been observed caring for the young of dead or missing comrades.

A team of  biologists has discovered that both these extreme behaviours are surprisingly common among green-rumped parrotlets, a small South American parrot. In a new study in the journal Proceedings of the National Academy of Sciences, the researchers present nearly 30 years of observations revealing what drives the parrotlets to either care for—or kill—one another's babies.

In parrotlets, infanticide and adoption revolve around real estate and love, according to this research. Most of the infanticide attacks happened when a breeding pair was attacked by another pair that was trying to take over a coveted nest site. It also occurred when males wanted to breed with a widow who already had offspring—but we were surprised to find that these new males were just as likely to adopt the offspring as attack them."

Among parrotlets, competition over nesting sites appears to be the primary motivation for attacks. Parrotlets killed or wounded nestlings and eggs at 256 of the nests that the biologists monitored. In most cases, the attacks were carried out by a single parrotlet or a breeding pair that later claimed the nesting site for themselves.

These attacks occurred more often when the parrotlet population was high and competition for good nesting sites was fierce.

It's not that everybody's born a killer, but the urge to breed is very strong. When the resources provided by the environment aren't enough for all individuals to breed, they seek out alternative strategies. Unfortunately, that involves killing innocent little offspring.

Infanticide also occurred in nests where one parent had died and the surviving parent had found a new mate. However, these new mates were just as likely to adopt the unrelated offspring as kill them—and choosing to become a stepparent ultimately did not hurt the parrotlet's reproductive success.

part 1

Comment by Dr. Krishna Kumari Challa 12 hours ago

New telomere findings may offer new insights for cancer treatments

A new study by  researchers shows that an enzyme called PARP1 is involved in repair of telomeres, the lengths of DNA that protect the tips of chromosomes, and that impairing this process can lead to telomere shortening and genomic instability that can cause cancer.

PARP1's job is genome surveillance: When it senses breaks or lesions in DNA, it adds a molecule called ADP-ribose to specific proteins, which act as a beacon to recruit other proteins that repair the break. The new findings, published in Nature Structural & Molecular Biology, are the first evidence that PARP1 also acts on telomeric DNA, opening up new avenues for understanding and improving PARP1-inhibiting cancer therapies.

In normal cells, genomic lesions occur naturally during DNA replication when a cell divides, and PARP1 plays an important role in fixing these errors. But while healthy cells have other DNA repair pathways to fall back on, BRCA-deficient cancers—which include many breast and ovarian tumors—rely heavily on PARP1 because they lack BRCA proteins, which control the most effective form of DNA repair called homologous replication.

When cancer cells can't make BRCA proteins, they become dependent on repair pathways that PARP1 is involved in. So, when you inhibit PARP1—which is the mechanism of several approved cancer drugs—cancer cells have no repair pathway available, and they die.

Deregulated DNA ADP-ribosylation impairs telomere replication, Nature Structural & Molecular Biology (2024). DOI: 10.1038/s41594-024-01279-6

Comment by Dr. Krishna Kumari Challa 12 hours ago

Freshly manufactured automobiles were making people feel ill!
Chemical-rich, and completely unavoidable, these distinct car aromas are but one of many allergens humans are exposed to while riding in automobiles.

From the steering wheel and dashboard, to armrests, headrests seats, and safety restraints, if it was man-made, chances are it was out-gassing noxious chemicals. All told, researchers found more than 275 different chemicals floating within these new car cabins, some of which bordered on being labeled as lethal.
Zero-in on Autocar’s findings surrounding the subject of new car interiors, and how they have the potential to make humans sick, and some disturbing trends begin to surface. The research reports point out eight common substances that are particularly prone to “diffusing” or “off-gassing,” with evidence showing that these toxic fumes continue to expel from surfaces, sometimes even months after assembly.
CAR PLASTICS, VOCS, ALLERGIES, AND YOUR HEALTH
The culprits are hazardous chemicals, like VOCs. Volatile organic compounds (VOCs) are probably the most recognizable evildoer in the world of hazardous inhalants. Some of the more commonplace poisonous compounds beneath this category include: acetaldehyde, acrolein, benzene, ethylbenzene, formaldehyde, styrene, toluene, and xylene.
While many of these dangerous substances have been identified as having an “adverse effect on occupants,” researchers report that, “VOCs can cause symptoms in humans like nausea, headaches, itchy eyes-basically, an allergic reaction.”

https://avalonking.com/blogs/news/toxic-cabin-interiors-why-that-ne....

Comment by Dr. Krishna Kumari Challa 12 hours ago

Your car may be slowly killing you

You're breathing potential carcinogens inside your car, says study

The air inside all personal vehicles is polluted with harmful flame retardants—including those known or suspected to cause cancer—according to a new study published in Environmental Science & Technology. Car manufacturers add these chemicals to seat foam and other materials to meet an outdated federal flammability standard with no proven fire-safety benefit.

Recent research found that interior materials release harmful chemicals into the cabin air of  cars. 

Considering the average driver spends about an hour in the car every day, this is a significant public health issue. It's particularly concerning for drivers with longer commutes as well as child passengers, who breathe more air pound for pound than adults.

The researchers detected flame retardants inside the cabins of 101 cars (model year 2015 or newer). In total, 99% of cars contained tris (1-chloro-isopropyl) phosphate (TCIPP), a flame retardant under investigation as a potential carcinogen. Most cars had additional organophosphate ester flame retardants present, including tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris (2-chloroethyl) phosphate (TCEP), two California Proposition 65 carcinogens. These and other flame retardants are also linked to neurological and reproductive harms.

About half of the cars were tested in both summer and winter. Warmer weather was linked to higher flame retardant concentrations because off-gassing from interior components like seat foam is increased by higher temperatures. Vehicle interiors can reach up to 150 degrees Fahrenheit.

The researchers also analyzed samples of seat foam from 51 of the cars in the study. Vehicles that contained the suspected carcinogen TCIPP in their foam tended to have higher concentrations of TCIPP in their air, confirming foam as a source of this flame retardant in cabin air.

Incidentally, firefighters are concerned that flame retardants contribute to their very high cancer rates.

You may be able to reduce your exposure to flame retardants in your car by opening your windows and parking in the shade.

But what's really needed is reducing the amount of flame retardants being added to cars in the first place. Commuting to work shouldn't come with a cancer risk. 

 Flame Retardant Exposure in Vehicles is Influenced by Use in Seat Foam and Temperature, Environmental Science & Technology (2024). DOI: 10.1021/acs.est.3c10440

Comment by Dr. Krishna Kumari Challa yesterday

Progression of Liver Disease Overview - Animated

Comment by Dr. Krishna Kumari Challa yesterday

Q: Why do women wear jasmine flowers in their hair?

Krishna: 

Jasmines usually come in summer. In summer you sweat a lot, especially near the sea, where the RH doesn’t allow your sweat to evaporate.

With sweat comes bacteria and body odour. So to camouflage that smell, women usually use sweet-smelling jasmine flowers.

That ‘s the reason given to me.

And I am not surprised. Even in Andhra and Telangana, people use this trick.

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