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                       JAI VIGNAN

All about Science - to remove misconceptions and encourage scientific temper

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  • Dr. Krishna Kumari Challa

    Relieving stress in insulin-producing cells protects against type 1 diabetes

    Removing a gene that manages stress within insulin-producing beta cells draws helpful attention from the immune system, protecting mice predisposed to type 1 diabetes from developing the disease, a new  study shows.

    The study also found that changes discovered in the modified mouse beta cells are also present in human beta cells that manage to survive the widespread beta-cell death that characterizes type 1 diabetes.

    This gives the researchers hope that their findings, published in the journal Cell Metabolism, may point to a potential new treatment that could be administered very early in the development of diabetes. 

    When we eat, our beta cells produce about 1 million molecules of insulin every minute to help maintain normal blood glucose levels. That is a big and stressful job, especially for a part of these beta cells called the endoplasmic reticulum.

    The endoplasmic reticulum is like the cell's warehouse staff. It folds the insulin protein molecules that a beta cell produces, packing them for shipping to other parts of the body. If something goes wrong with the protein folding process, the shipping process backs up or even stops, stressing the endoplasmic reticulum. A stress-response gene called Atf6 perks up when a cell is struggling with unfolded proteins. But if Atf6 can't resolve the protein-folding problem, prolonged stress will eventually kill the cell.

    Scientists bred a line of diabetes-predisposed mice without the Atf6 gene in their beta cells. Instead of meeting their typical fate, those mice were protected from diabetes. Analysis of the genes expressed by their beta cells suggested the cells entered a state called senescence far ahead of schedule.

    Senescence is a period of the cell's life cycle in which it stops dividing and halts other normal cellular business. Senescing cells can cause problems for neighboring cells by releasing inflammatory messaging molecules that trigger an immune system response.

    When researchers removed—knocked-out—the Atf6 gene in the beta cells in the pancreas of their mouse model of type 1 diabetes, and they did not become diabetic. Instead of dying off, these cells unexpectedly appear to go into an early senescence state that initiated a beneficial immune response and helped the cells survive an autoimmune attack.

    DNA damage, stress and aging can kick off senescence, which can draw an immune system response that cleans up the senescent cells. If the immune system fails to clear these cells, they accumulate and cause chronic inflammation and disease.

    The beta cells without Atf6 exhibit transient senescence and start releasing this group of proteins, including leukemia inhibitory factor, or LIF, that recruits protective immune cells called M2 macrophages.

    Part 1

  • Dr. Krishna Kumari Challa

    Even more exciting is how closely the new study's results in mice appear to be reflected in human cells.

    With a blood test, doctors can identify people who are at high-risk of developing type 1 diabetes months in advance of the death of their beta cells.

    That may be a perfect timeframe for a treatment based on pharmacological inhibition of Atf6 or induction of LIF and other secreted proteins. If we can get there in time to protect these cells with transient senescence, the onset of diabetes might be prevented.

    Hugo Lee et al, Stress-induced β cell early senescence confers protection against type 1 diabetes, Cell Metabolism (2023). DOI: 10.1016/j.cmet.2023.10.014

    Part 2

  • Dr. Krishna Kumari Challa

    Earth's Moon: Why One Side Always Faces Us

  • Dr. Krishna Kumari Challa

    Astronomers find dozens of massive stars fleeing the Milky Way

    The Milky Way can't hold onto all of its stars. Some of them get ejected into intergalactic space and spend their lives on an uncertain journey. A team of astronomers took a closer look at the most massive of these runaway stars to see what they could find out how they get ejected.

    When astronomers observe a field of stars in the Milky Way, one of the things they measure is the velocity distribution. The overall velocity distribution of the stellar population reflects the rotation of the galaxy. And when a star isn't harmonized with the galaxy's rotation, it catches astronomers' attention.

    A team of astronomers working with two catalogues of massive stars found a whole bunch of stars moving differently than the galaxy. They're runaway stars that are on their way out of the galaxy.

    Nobody knows how many runaway stars are on their way out of our galaxy, but astronomers keep finding more of them. Some estimates say there are 10 million runaway stars fleeing the Milky Way, but we don't know for sure. It may depend on the mechanism that drives them away, and that's something astrophysicists don't fully understand. A new study aims to shed some light on the runaway star phenomenon by looking specifically at massive stars.

    A relevant fraction of massive stars are runaway stars. These stars move with a significant peculiar velocity with respect to their environment.

    Massive early-type OB stars are the most luminous stars in the Milky Way. OB stars are not only massive and young, they're extremely hot. They form in loosely organized groups with one another called OB associations. Because they're young and hot, they don't last long. They're important in astronomy because they're so massive and energetic and because many of them explode as supernovae. That's why there are specific catalogues dedicated to them.

    Part 1

  • Dr. Krishna Kumari Challa

    Why do massive stars make up such a high proportion of runaway stars? There are two competing theories that attempt to explain runaway stars, and both involve massive stars. One is the dynamical ejection scenario (DES), and the other is the binary supernova scenario (BSS).

    OB stars often form in binary pairs. In the BSS, one star explodes as a supernova, and the explosion kicks the other star. If the situation is right, the surviving star is given enough energy in the right direction that it can escape from its bond with its partner, which is now a neutron star or a black hole. It can also escape the gravitational pull of the Milky Way. If that happens, it begins its long journey into intergalactic space.

    In the DES, there's no dramatic supernova explosion. Instead, a star in a compact, densely packed region experiences gravitational interactions with other stars. Encounters between binary and single stars can produce runaways, and so can encounters between two binary pairs. The OB associations where O-type and B-type stars tend to form are the types of dense environments that can trigger runaway stars. Since most of these stars are massive, most of the runaway stars are, too.

    Scientists have been wondering about the two scenarios and debating them for decades. Both scenarios can produce stars with enough velocity to escape the galaxy. In studying their sample of 175 runaway stars, the researchers found that their data favors one explanation over the other.

    The higher percentages and higher velocities found for O-type compared to Be-type runaways underline that the dynamical ejection scenario is more likely than the binary supernova scenario.

    The percentages of spectral types represented in runaway stars help explain their conclusion. 25% of the O-type stars in their sample are runaways versus 5% of the Be-type. Other studies have come up with different numbers, but as the researchers point out, there is agreement in the sense that the percentage of runaway O stars is significantly higher than for B or Be stars.

    Previous research shows that O-type runaway stars have higher velocities than B and Be-type stars. Previous research also shows that dynamical ejection often results in faster, more massive runaways than the binary supernova scenario. 

    M. Carretero-Castrillo et al, Galactic runaway O and Be stars found using Gaia DR3, Astronomy & Astrophysics (2023). DOI: 10.1051/0004-6361/202346613. On arXivDOI: 10.48550/arxiv.2311.01827

    Part 2

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  • Dr. Krishna Kumari Challa

    World's First Entire Eye Transplant

    A team of surgeons in New York has performed the world's first transplant of an entire eye in a procedure widely hailed as a medical breakthrough, although it isn't yet known whether the man will ever see through the donated eye. The groundbreaking surgery involved removing part of the face and the whole left eye – including its blood supply and optic nerve – of a donor and grafting them onto a lineworker from Arkansas who survived a 7,200-volt electric shock in June 2021.

    Aaron James, 46, suffered extensive injuries including the loss of his left eye, his dominant left arm above the elbow, his nose and lips, front teeth, left cheek area and chin.
    He was referred to NYU Langone Health, a leading medical center for facial transplants, which carried out the procedure on May 27.

    Transplanting an entire eye has long been a holy grail of medical science, and though researchers have had some success in animals – where they have restored partial vision – it's never before been performed in a living person.
    The transplanted left eye appears very healthy, said retinal ophthalmologist.
    It has a good blood supply, is maintaining its pressure, and is generating an electrical signal, though James is not yet able to see. But the doctors have a lot of hope.
    The doctors used bone marrow-derived adult stem cells to promote nerve repair.
    Source: News Agencies
  • Dr. Krishna Kumari Challa

    How animals get their stripes and spots

    Nature has no shortage of patterns, from spots on leopards to stripes on zebras and hexagons on boxfish. But a full explanation for how these patterns form has remained elusive.

    Now engineers  have shown that the same physical process that helps remove dirt from laundry could play a role in how tropical fish get their colorful stripes and spots. Their findings were published Nov. 8 in the journal Science Advances.

    Biologists have previously shown that many animals evolved to have coat patterns to camouflage themselves or attract mates. While genes encode pattern information like the color of a leopard’s spots, genetics alone do not explain where exactly the spots will develop, for example.

    In 1952, before biologists discovered the double helix structure of DNA, Alan Turing, the mathematician who invented modern computing, proposed a bold theory of how animals got their patterns.

    Turing hypothesized that as tissues develop, they produce chemical agents. These agents diffuse through tissue in a process similar to adding milk to coffee. Some of the agents react with each other, forming spots. Others inhibit the spread and reaction of the agents, forming space between spots. Turing’s theory suggested that instead of complex genetic processes, this simple reaction-diffusion model could be enough to explain the basics of biological pattern formation.

    Surely Turing’s mechanism can produce patterns, but diffusion doesn’t yield sharp patterns.

    Where particles  form sharply defined stripes,  the process known as diffusiophoresis plays a role in nature’s pattern formation.

    Diffusiophoresis happens when a molecule moves through liquid in response to changes, such as differences in concentrations, and accelerates the movement of other types of molecules in the same environment. While it may seem like an obscure concept to non-scientists, it’s actually how laundry gets clean.

    One recent study showed that rinsing soap-soaked clothes in clean water removes the dirt faster than rinsing soap-soaked clothes in soapy water. This is because when soap diffuses out of the fabric into water with lower soap concentration, the movement of soap molecules draws out the dirt. When the clothes are put in soapy water, the lack of a difference in soap concentration causes the dirt to stay in place.

    The movement of molecules during diffusiophoresis, as researchers observed in their simulations, always follows a clear trajectory and gives rise to patterns with sharp outlines. To see if it may play a role in giving animals their vivid patterns, researchers ran a simulation of the purple and black hexagonal pattern seen on the ornate boxfish skin using only the Turing equations. The computer produced a picture of blurry purple dots with a faint black outline. Then the team modified the equations to incorporate diffusiophoresis. The result turned out to be much more similar to the bright and sharp bi-color hexagonal pattern seen on the fish.

    The research team’s theory suggests that when chemical agents diffuse through tissue as Turing described, they also drag pigment-producing cells with them through diffusiophoresis—just like soap pulls dirt out of laundry. These pigment cells form spots and stripes with a much sharper outline.

     Benjamin Alessio et al, Diffusiophoresis-Enhanced Turing Patterns, Science Advances (2023). DOI: 10.1126/sciadv.adj2457www.science.org/doi/10.1126/sciadv.adj2457

  • Dr. Krishna Kumari Challa

    New antifungal molecule kills fungi without toxicity in human cells, mice

    A new antifungal molecule, devised by tweaking the structure of prominent antifungal drug Amphotericin B, has the potential to harness the drug’s power against fungal infections while doing away with its toxicity, researchers  reported in the journal Nature.

    Amphotericin B, a naturally occurring small molecule produced by bacteria, is a drug used as a last resort to treat fungal infections. While AmB excels at killing fungi, it is reserved as a last line of defense because it also is toxic to the human patient – particularly the kidneys.

    This work is a demonstration that, by going deep into the fundamental science, you can take a billion-year head start from nature and turn it into something that hopefully is going to have a big impact on human health.

    These researchers spent years exploring AmB in hopes of making a derivative that can kill fungi without harm to humans. In previous studies, they developed and leveraged a building block-based approach to molecular synthesis and teamed up with a group specializing in molecular imaging tools called solid-state nuclear magnetic resonance. They  uncovered the mechanism of the drug: AmB kills fungi by acting like a sponge to extract ergosterol from fungal cells.

    The researchers also found that that AmB similarly kills human kidney cells by extracting cholesterol, the most common sterol in people. The researchers also resolved the atomic-level structure of AmB sponges when bound to both ergosterol and to cholesterol.

    Using this structural information along with functional and computational studies, they achieved a significant breakthrough in understanding how AmB functions as a potent fungicidal drug. This provided the insights to modify AmB and tune its binding properties, reducing its interaction with cholesterol and thereby reducing the toxicity.

    Part 1

  • Dr. Krishna Kumari Challa

     They began synthesizing and testing derivatives with slight changes to the region that binds to ergosterol and cholesterol, while also boosting the kinetics of the ergosterol-removing process to maintain efficacy.

     The researchers tested the most promising derivatives – first with in vitro assays, quickly assessing the efficacy in killing fungi; then moving to cell cultures and eventually live mice, assessing toxicity.

    The researchers tested this molecule against over 500 different clinically relevant pathogen species in four different locations. And this molecule completely surprised us by either mimicking or surpassing the efficacy of current clinically available antifungal drugs.

    The researchers tested AM-2-19 in human blood and kidney cells to screen for toxicity. They also tested AM-2-19 in mouse models of three common, stubborn fungal infections and saw high efficacy.

    Maji, A. et al. Tuning sterol extraction kinetics yields a renal-sparing polyene antifungal. Nature https://doi.org/10.1038/s41586-023-06710-4 (2023).

    Part 2

  • Dr. Krishna Kumari Challa

    Semantic hearing: Future of intelligent hearables

  • Dr. Krishna Kumari Challa

    Liver cells age differently depending on where they are in the organ

     People age at different rates. But what about inside of a living body? Do all cells age in the same way? And does the location of a cell in the organ make a difference to the ageing process? Researchers  have now shown in the liver of mice that liver cells age differently depending on where they are located in the organ.

    The liver is largely made up of a single type of cell, the hepatocyte. Depending on where they are in the liver, they have different roles. Near the portal vein, where fresh, oxygen-rich blood enters the liver, hepatocytes use the oxygen to process fats in their mitochondria and produce energy. In contrast, carbohydrates are broken down in the less oxygen-rich regions of the liver. "In the liver, the position of the hepatocyte in the organ plays a crucial role. That's why the liver was the perfect model for us to investigate whether location also makes a difference in ageing.

    The location of the liver cells has a strong influence on the ageing process. In the region of the liver where the liver cells use oxygen for energy production in their mitochondria, this process deteriorates significantly with age. In the central, oxygen-deprived area of the liver, however, the researchers found no change in the mitochondria, but a change in the cells' fat metabolism.

    It is important where a cell ages. They age differently depending on where they are located and what their function is, according to these researchers. 

    https://www.mpg.de/21085057/1109-balt-location-location-location-15...

  • Dr. Krishna Kumari Challa

    Each of Your Nostrils Smells The World Uniquely, Study Reveals

    It's not immediately noticeable to us, but our two nostrils are actually working independently in some ways and appear to have their own separate sense of smell.

    That's the conclusion of a new study from researchers in the US that could teach us much more about the brain and how senses are processed. The findings build on earlier studies in animals and humans, indicating that our brains might be capable of processing each nostril's input individually as well as synthesizing them into one complete whole.

    To look more closely at smelling in stereo, the researchers from the University of Pennsylvania, the Barrow Neurological Institute, and Ohio State University enlisted the help of 10 epilepsy patients who had already had electrodes implanted in their brains.

    One of three different scents, as well as a control consisting of pure air, was puffed into either nostril or both together in each trial. After several seconds, the subject was asked to identify the smell, then state which nostril they used to detect it - left, right, or both. Meanwhile, the researchers collected data on the brain's response via the electrodes.

    The team made a number of interesting observations. For example, when the same smell was presented to each nostril in turn, the resulting brain activity was similar, but not identical, suggesting some independence.

    What's more, smelling through two nostrils together created two distinct bursts of activity. Though the time delay between them was very short, it was there, and the researchers suggest that this again points to the nostrils not always being in unison. Two nostrils were better than one when it came to identifying odors and identifying them more quickly, which hints that there's definitely some benefit to having two nostrils rather than one – as with eyes and ears. The analysis concentrated on the piriform cortex (PC) brain region, where the sense of smell is handled and interpreted. As we already know, our different senses are closely interconnected too, which means the findings may have implications beyond smell.

    https://www.cell.com/current-biology/fulltext/S0960-9822(23)01379-9

  • Dr. Krishna Kumari Challa

    Forests with multiple tree species are 70% more effective as carbon sinks than monoculture forests, study finds

    To slow the effects of climate change, conserve biodiversity, and meet the sustainable development goals, replanting trees is vital. Restored forests store carbon within the forest's soil, shrubs, and trees. Mixed forests are especially effective at carbon storage, as different species with complementary traits can increase overall carbon storage.

    Compared to single-species forests, mixed forests are also more resilient to pests, diseases, and climatic disturbances, which increases their long-term carbon storage potential. The delivery of other ecosystem services is also greater in mixed species forests, and they support higher levels of biodiversity.

    Although the benefits of diverse forest systems are well known, many countries' restoration commitments are focused on establishing monoculture plantations. Given this practice, an international team of scientists has compared carbon stocks in mixed planted forests to carbon stocks in commercial and best-performing monocultures, as well as the average of monocultures.

    Diverse planted forests store more carbon than monocultures—upwards of 70%. Researchers also found the greatest increase in carbon storage relative to monocultures in four-species mixtures.

    The mixed planted forests assessed in the study ranged in species richness from two to six species. In the data set the scientists worked with, four-species mixtures were the most effective carbon sinks. One such mix was made up from different broadleaf trees. Mixes with two species also had greater above-ground carbon stocks than monocultures and stored up to 35% more carbon. 

    Accordingly, the researchers were able to show that diversification of forests enhances carbon storage. Altogether, above-ground carbon stocks in mixed forests were 70% higher than in the average monoculture. The researchers also found that mixed forests had 77% higher carbon stocks than commercial monocultures, made up of species bred to be particularly high yielding.

    Young mixed planted forests store more carbon than monocultures—a meta-analysis, Frontiers in Forests and Global Change (2023). DOI: 10.3389/ffgc.2023.1226514

  • Dr. Krishna Kumari Challa

    Physicists trap electrons in a 3D crystal for the first time

     Electrons move through a conducting material like commuters at the height of Manhattan rush hour. The charged particles may jostle and bump against each other, but for the most part they’re unconcerned with other electrons as they hurtle forward, each with their own energy.

    But when a material’s electrons are trapped together, they can settle into the exact same energy state and start to behave as one. This collective, zombie-like state is what’s known in physics as an electronic “flat band,” and scientists predict that when electrons are in this state they can start to feel the quantum effects of other electrons and act in coordinated, quantum ways. Then, exotic behavior such as superconductivity and unique forms of magnetism may emerge.

    Now, physicists have successfully trapped electrons in a pure crystal. It is the first time that scientists have achieved an electronic flat band in a three-dimensional material. With some chemical manipulation, the researchers also showed they could transform the crystal into a superconductor — a material that conducts electricity with zero resistance.

    The electrons’ trapped state is possible thanks to the crystal’s atomic geometry. The crystal, which the physicists synthesized, has an arrangement of atoms that resembles the woven patterns in “kagome,” the Japanese art of basket-weaving. In this specific geometry, the researchers found that rather than jumping between atoms, electrons were “caged,” and settled into the same band of energy.

    The researchers say that this flat-band state can be realized with virtually any combination of atoms — as long as they are arranged in this kagome-inspired 3D geometry. The results, published in Nature, provide a new way for scientists to explore rare electronic states in three-dimensional materials. These materials might someday be optimized to enable ultraefficient power lines, supercomputing quantum bits, and faster, smarter electronic devices.

    https://news.mit.edu/2023/physicists-trap-electrons-3d-crystal-firs...

  • Dr. Krishna Kumari Challa

    The Remains of an Ancient Planet Lie Deep Within Earth

  • Dr. Krishna Kumari Challa

    Mind-Altering Cat Parasite May Trigger Frailty in Older People

    An infamous parasite primarily carried by cats, Toxoplasma gondii, could be responsible for increased frailty in older adults, a new study reveals.

    The discovery, made by an international team of researchers, adds to what we already know about T. gondii: that it can cause flu-like symptoms in many, and more serious issues such as seizures in people with weaker immune systems. "We often think of T. gondii infection as relatively asymptomatic, but this study highlights that for some people it may have significant health consequences later on.

    The research team suspected that the parasite may be one of the causes of 'inflammaging', or persistent age-related inflammation that contributes to frailty. Blood tests from 601 Spanish and Portuguese adults aged over 65 were analyzed for measures of frailty, including unintentional weight loss, tiredness, and loss of mental sharpness. While there wasn't an association found between T. gondii infections and frailty, among those who had been infected by T. gondii, people who produced a higher number of antibodies to fight it were more likely to show signs of being frail. To put it another way, there are signs of a link between a more severe immune reaction to this parasite, and a greater likelihood of being more frail in old age. It's not enough to prove cause and effect, but it seems there might be something going on. On the inflammaging front, those with a stronger response to T. gondii (perhaps through a more widespread infection, or multiple infections) also had higher levels of certain biomarkers of inflammation, suggesting another potential link there.

    Considering infection rates for T. gondii rise as people get older, and that it can lie dormant and undetected in a human body for several decades, the researchers say we need to be even more careful when it comes to avoiding infection. That can come through exposure to T. gondii eggs (in a cat's litter box, for example, or water that they've contaminated), or through eating undercooked meat that's been infected by the parasite. Keeping cats indoors and avoiding strays can help too.

    https://academic.oup.com/biomedgerontology/advance-article/doi/10.1...

  • Dr. Krishna Kumari Challa

    All fireworks, including the green ones, are bad ! Did you know that Deepavali fireworks cause more distress than happiness? So we celebrate Diwali without any fireworks! All these years I never ever touched even a single one. We have been celebrating  Deepavali with fun and happiness minus fireworks for the past few years. Before somebody asks me 'How can there be fun without fireworks?', I want to add I had fun because I didn't contribute to the pollution. I didn't send out a toxic concoction into the atmosphere that rains down heavily into lakes, rivers, seas, fields and houses. I am not responsible for someone developing hypothyroidism, anemia or cancer. And I am extremely happy because of this! Fireworks get their flamboyance from a variety of chemicals, many of which are toxic to humans. From the gunpowder that fuels their flight to the metallic compounds that colour their explosions, fireworks often contain carcinogenic or hormone-disrupting substances that can seep into soil and water, not to mention the lung-clogging smoke they release and plastic debris they scatter. Almost all the major cities in India that have measured Deepavali festival-raised pollution levels recently sounded alarm bells. Some people justify their acts of using fireworks by saying that these harmful gases released into the atmosphere actually kill mosquitoes and other harmful insects! But these insects might already have developed resistance to these chemicals. Moreover, if they are harmful to some living beings, they would equally be harmful to the other ones (human beings) too! First the ever evolving fireworks tempt you and make you buy them at sky-rocketing prices causing distress to your earning loved ones. Fire accidents are quite common during this festival. The flying fire bits also get into unprotected eyes and burn eye parts, especially the cornea leading to blindness. Apart from causing agony to the animal life, the loud noises also increase hearing distress and the toxic smoke released into the atmosphere can get lodged in people's lungs and enhance asthmatic symptoms and severe breathing problems in human beings. Anybody considering him/her-self environmentally conscious and responsible will never go anywhere near these fireworks as they pose a serious environmental and health danger from heavy metals and other toxic firework fallout. So celebrate Diwali without fireworks like we do. 

  • Dr. Krishna Kumari Challa

    Our Galaxy's Heart Is Pulsing With a Mysterious Signal

    Compared to some other galaxies out there, the supermassive black hole at the heart of the Milky Way isn't a particularly active one. It's not guzzling down scads of material, and it's not blasting giant jets of plasma into space. Even a relatively peaceful supermassive black hole, however, is a wild, savage beast, and our own – named Sagittarius A* – has been recorded doing some pretty strange things. And now there's a new one: astrophysicists Gustavo Magallanes-Guijón and Sergio Mendoza of National Autonomous University of Mexico have recorded it sort of… pulsing. Every 76 minutes, like clockwork, the gamma-ray flux of Sgr A fluctuates. This, the researchers say, is similar in periodicity to changes in the black hole's radio and X-ray emission too, suggesting an orbital motion of something whirling madly around the black hole.

    https://arxiv.org/abs/2311.05875

  • Dr. Krishna Kumari Challa

    Exoplanet Types: Worlds Beyond Our Solar System

  • Dr. Krishna Kumari Challa

    Data reveal possible reason some exoplanets are shrinking

    A new study could explain the "missing" exoplanets between super-Earths and sub-Neptunes.

    Some exoplanets seem to be losing their atmospheres and shrinking. In a new study using NASA's retired Kepler Space Telescope, astronomers find evidence of a possible cause: The cores of these planets are pushing away their atmospheres from the inside out.

    The study is published in The Astronomical Journal.

    Exoplanets (planets outside our solar system) come in a variety of sizes, from small, rocky planets to colossal gas giants. In the middle lie rocky super-Earths and larger sub-Neptunes with puffy atmospheres. But there's a conspicuous absence—a "size gap"—of planets that fall between 1.5 to 2 times the size of Earth (or in between super-Earths and sub-Neptunes) that scientists have been working to better understand.

    Scientists have now confirmed the detection of over 5,000 exoplanets, but there are fewer planets than expected with a diameter between 1.5 and 2 times that of Earth. Exoplanet scientists have enough data now to say that this gap is not a fluke. There's something going on that impedes planets from reaching and/or staying at this size.

    Researchers think that this gap could be explained by certain sub-Neptunes losing their atmospheres over time. This loss would happen if the planet doesn't have enough mass, and therefore gravitational force, to hold onto its atmosphere. So sub-Neptunes that aren't massive enough would shrink to about the size of super-Earths, leaving the gap between the two sizes of planets.

    But exactly how these planets are losing their atmospheres has remained a mystery. Scientists have settled on two likely mechanisms: One is called core-powered mass loss; and the other, photoevaporation. The new study has uncovered new evidence supporting the first.

     Jessie L. Christiansen et al, Scaling K2. VII. Evidence For a High Occurrence Rate of Hot Sub-Neptunes at Intermediate Ages, The Astronomical Journal (2023). DOI: 10.3847/1538-3881/acf9f9

  • Dr. Krishna Kumari Challa

    Microplastics found in clouds could affect the weather

    From the depths of the seas to snow on mountains and even the air above cities, microplastics are turning up increasingly often. Now, in Environmental Science & Technology Letters, researchers have analyzed microplastics in clouds above mountains. They suggest that these tiny particles could play a role in cloud formation and, in turn, affect weather.

    Microplastics—plastic fragments smaller than five millimeters—originate from a myriad of items used daily, such as clothing, packaging and car tires.

    As research in the field evolves, scientists are not only detecting microplastics in the atmosphere but also investigating how they may play a role in cloud formation. For example, a group of researchers recently detected plastic granules, which had water-attracting surfaces, in Japanese mountaintop clouds.

    So, to learn more, researchers set out to look for microplastics in mountain clouds, used computer models to figure out how they could have gotten there, and tested how the particles could have impacted—and been impacted by—the clouds.

    Wang and the team first collected 28 samples of liquid from clouds at the top of Mount Tai in eastern China. Then they analyzed the samples and found:

    • Low-altitude and denser clouds contained greater amounts of microplastics.
    • Particles were made of common polymers, including polyethylene terephthalate, polypropylene, polyethylene, polystyrene and polyamide.
    • The microplastics tended to be smaller than 100 micrometers in length, although some were as long as 1,500 micrometers.
    • Older, rougher particles had more lead, mercury and oxygen attached to their surfaces, which the researchers suggest could facilitate cloud development.

    Part 1

  • Dr. Krishna Kumari Challa

    Research models suggested that airflow from highly populated inland areas, rather than from over the ocean or other nearby mountains, served as the major source of the fragments.

    In laboratory experiments, the researchers demonstrated that microplastics exposed to cloud-like conditions—ultraviolet light and filtered cloud-sourced water—had smaller sizes and rougher surfaces than those exposed to pure water or air. Additionally, particles impacted by the cloud-like conditions had more lead, mercury and oxygen-containing groups.

    These results suggest that clouds modify microplastics in ways that could enable the particles to affect cloud formation and the fate of airborne metals. However, more work is needed to fully understand how microplastics affect clouds and the weather.

    Characterization of Microplastics in Clouds over Eastern China, Environmental Science & Technology Letters (2023). DOI: 10.1021/acs.estlett.3c00729pubs.acs.org/doi/abs/10.1021/acs.estlett.3c00729

    Part 2

  • Dr. Krishna Kumari Challa

    Researchers discover alternative cosmic source of gold

    Researchers have discovered that the explosion of a low-mass neutron star can be the alternative cosmic source for lanthanides and other heavy elements, including precious metals such as gold and platinum.

    Neutron stars are the evolutionary end points of stars with a mass between 10 to 25 times that of the sun. After the final explosion, the star leaves behind a compact object with a mass comparable to the sun, and a diameter of about 20 km (the size of Manhattan). Such a compact object is stable enough to exist alone. But in a binary neutron star system, the interaction with the companion neutron star can trigger something dramatic. Traditionally, when two neutron stars are close enough, they merge and collide. This process is the major source of lanthanides and heavy elements in the universe. The collision can create the condition (known as the r-process) for the synthesis of these elements. The merger event was recently observed for the first time in 2017. However, it is highly uncertain if this channel alone is sufficient to explain the heavy elements in the cosmic scale. The team noticed that even without direct collision, the primary neutron star can lose mass to its companion neutron star by tidal force. Theoretical models expect that after shedding sufficient mass, the star becomes unstable, and it triggers uncontrolled pulsation and the later explosion.

    The new results  confirm that the individual low mass neutron star is unstable, and it can explode. The chemical composition of the ejecta closely resembles the solar composition, especially in heavy elements. This suggests that this scenario could be another important method to explain the chemical element distribution in the universe.

    This study sheds light on one of the fundamental questions about the universe: where all the chemical elements come from, and how did the universe evolve from only hydrogen and helium to a diversity of 118 elements. Lanthanides have close relations with modern technology. For example, neodymium is the main ingredient for manufacturing strong magnets. Heavy elements including precious metals, i.e., gold and platinum, are also abundantly produced by this channel.

     Chun-Ming Yip et al, R-process Nucleosynthesis of Subminimal Neutron Star Explosions, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acf570

  • Dr. Krishna Kumari Challa

    50 Years of Data Links Insecticides to Global Decline of Human Sperm Counts: Meta Analysis

    Insecticide exposure has been linked to lower sperm concentration in adult men worldwide, according to a new review of 25 studies spanning almost 50 years. The research team  says it's the most thorough systematic review of the topic so far.

    These are strong findings as their method takes into account each study's limitations, so their published paper recommends reducing exposure to the two types of insecticides studied to preserve male fertility and increase the changes of parenthood.

    people are primarily exposed to insecticides through the consumption of contaminated food and water.

    These commonly-used insecticides' main mode of toxicity is the inhibition of enzymes involved in the normal breakdown of neurotransmitters like acetylcholine.

    "No matter how you looked at it, the smaller studies or the larger studies, there was a consistent association with increased exposure to insecticides associated with decreased sperm concentration", according to the researchers.

    The researchers note other studies have shown that semen quality is declining over time. A review in 2022 found that the average sperm count among participants, who were not considered infertile dropped by 51 percent between 1973 and 2018, from 101.2 million to 49 million per millilitre of semen.

    There's a correlation between low sperm concentration and other factors of male health too, such as an increased risk of some cancers. However, finding two things to be related doesn't prove that one is responsible for or a result of the other, and we still don't know the mechanism behind the effects.

    https://ehp.niehs.nih.gov/doi/10.1289/EHP12678

  • Dr. Krishna Kumari Challa

    1 in 50 Million Chance: US Woman With Rare Double Uterus Is Pregnant in Both

     A 32-year-old woman from Alabama who was born with two uteruses is now pregnant in both.

    Kelsey Hatcher, who is documenting her story on her Instagram account "doubleuhatchlings," knew from the age of 17 she has "uterus didelphys," a rare condition where a person has a double uterus, thought to affect about 0.3 percent of females.

    It was during a routine eight-week ultrasound visit in May that the mother-of-three learned not only that she was having twins this time around – but that a fetus was present in each of her uteruses.

    Most likely what happened is that she ovulated separately and had one egg come down each fallopian tube, meaning coming down on each side of the uterus, and then sperm traveled up on each separate uterus and fertilization occurred separately, according to her doctors. Both the fetuses are healthy.

    Pregnancies in both uteruses are exceedingly rare – the odds were 1 in 50 million – with the last widely known case occurring in Bangladesh in 2019 when Arifa Sultana, then 20, gave birth to healthy twins 26 days apart.​

    But the uteruses will contract at different times, which could be minutes, hours or even days apart, and the woman and her husband  are aware Cesarean sections – for one, or both – could be needed, depending on how things unfold.

    Source: 

    Agence France-Presse

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  • Dr. Krishna Kumari Challa

    Kelsey's ultrasound shows both of her uteruses with a baby in each. Source: (doubleuhatchlings/Instagram)


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  • Dr. Krishna Kumari Challa

    1.3 million lives lost every year in just seven countries: The devastating impact of tobacco revealed

    Every year 1.3 million lives are lost to cancers caused by smoking tobacco across the UK, US and BRICS nations (Brazil, Russia, India, China and South Africa), according to a new study.

    Researchers have found that together, the seven countries represented more than half of the global burden of cancer deaths every year. They concluded that smoking, as well as three other preventable risk factors—alcohol, overweight or obesity, and human papillomavirus (HPV) infections—caused almost 2 million deaths combined.

    Researchers concluded that the four preventable risk factors resulted in over 30 million years of life lost each year. Smoking tobacco had by far the biggest impact—leading to 20.8 million years of life being lost, the study said.

    Some of the other key findings from the study include:

    • Preventable risk factors were associated with different cancer types in different places. For example, in India, there were more premature deaths from head and neck cancer in men, and gynecological cancer in women, but in every other country, tobacco smoking caused the most years of life to be lost to lung cancer.
    • Researchers believe that this is due to differences in each of the countries—cervical screening is less comprehensive in India and South Africa than in other countries like the UK and US, which would explain why there are more premature deaths from gynecological cancers due to HPV infection in India and South Africa. The higher number of years of life lost to head and neck cancer in men in India could be explained by smoking habits being different to those in the UK, with the general population smoking different tobacco products.
    • There are gender differences in the number of cancer deaths and years of life lost to different risk factors. Men have higher rates of years of life lost to smoking and drinking alcohol, because smoking and drinking rates tend to be higher in men. In China, India and Russia, rates of years of life lost to tobacco smoking and alcohol were up to nine times higher in men than women.
    • Meanwhile, being overweight or obese, and HPV infection, led to more cancer deaths and years of life lost in women than in men. In South Africa and India, HPV led to particularly high rates of years of life lost with a large gender imbalance. Rates were 60 times higher in women than men in South Africa, and 11 times higher in India, which highlights the urgent need for improved access to cervical screening and the HPV vaccination in these countries.
    • The differences in cancers linked to HPV infection are stark—mortality rates are six times higher in South Africa than in the UK and US. Cervical cancer has been largely prevented by screening in the UK and US, and is on track to be almost eliminated through HPV vaccination in the UK.

    International burden of cancer deaths and years of life lost from cancer attributable to four major risk factors: a population-based study in Brazil, Russia, India, China, South Africa, the United Kingdom, and United States, eClinicalMedicine (2023).

  • Dr. Krishna Kumari Challa

    New studies of brain activity explain benefits of electroconvulsive therapy

    Electroconvulsive therapy (ECT), formerly known as electroshock therapy, involves inducing a brief seizure in the brain using controlled doses of electricity. While ECT is highly effective for certain mental illnesses, particularly depression, the reasons for its efficacy have long puzzled the fields of psychiatry and neuroscience.

    Now, researchers  may have an answer. In two new studies published in Translational Psychiatry, they propose a new hypothesis that ECT alleviates depression symptoms by increasing aperiodic activity, a type of electrical activity in the brain that doesn't follow a consistent pattern and is generally considered to be the brain's background noise.

    Electroconvulsive therapy has a great track record, but a bad reputation. The therapy is effective in up to 80% of patients who receive the treatment, most often for depression but occasionally for bipolar disorder or schizophrenia. However, despite this high success rate, electroconvulsive therapy is frequently associated with frightening images of people receiving painful, high voltage shocks.

    A lot of people are surprised to learn that doctors still use electroconvulsive therapy, but the modern procedure uses highly controlled dosages of electricity and is done under anesthesia. It really doesn't look like what you see in movies or television.

    While generally safe and effective, ECT does have drawbacks, including temporary confusion and cognitive impairment. It also requires multiple outpatient visits, which can present a barrier to some people who might otherwise benefit from the treatment.

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    One of the reasons ECT isn't more popular is that for a lot of people, it's easier and more convenient to just take a pill. However, in people for whom medications don't work, electroconvulsive therapy can be life-saving. Understanding how it works will help us discover ways to increase the benefits while minimizing side effects.

    The researchers used electroencephalography (EEG) scans to study the brain activity of patients who received ECT therapy for depression. They also looked at another similar form of treatment called magnetic seizure therapy, which induces a seizure with magnets instead of electrodes. Both therapies showed increased aperiodic activity levels in patients' brains post-treatment.

    One of the functions of aperiodic activity in the brain is helping control how neurons turn on and off. Our neurons are constantly going through cycles of excitation and inhibition that correspond with different mental states. Aperiodic activity helps boost inhibitory activity in the brain, effectively slowing it down.

    Something we see regularly in the EEG scans of people who receive electroconvulsive or magnetic seizure therapy is a slowing pattern in the brain's electrical activity. This pattern has gone unexplained for many years, but accounting for the inhibitory effects of aperiodic activity helps explain it. It also suggests that these two forms of therapy are causing similar effects in the brain.

     Translational Psychiatry (2023). doi.org/10.1038/s41398-023-02631-y

    Translational Psychiatry (2023). doi.org/10.1038/s41398-023-02634-9

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  • Dr. Krishna Kumari Challa

    Bear genes show circadian rhythms even during hibernation

    The internal clocks of grizzly bears appear to keep ticking through hibernation, according to a genetic study. This persistence highlights the strong role of circadian rhythms in the metabolism of many organisms including humans.

    The genetic study confirmed observational evidence that bears' energy production still waxes and wanes in a daily pattern even as they slumber for several months without eating. The researchers also found that during hibernation the amplitude of the energy production was blunted, meaning the range of highs and lows was reduced. The peak also occurred later in the day under hibernation than during the active season, but the daily fluctuation was still there.  

    This underscores the importance of the circadian rhythms themselves—that they give organisms the flexibility to still function in a state as extreme as a hibernating bear.

    Other research has shown that circadian rhythms, the 24-hour physical cycles common to most living animals on Earth, have ties to metabolic health. In humans, major disruptions to these patterns, such as occur in night shift work, have been linked to metabolic problems like weight gain and higher prevalence of diabetes.

    Ellery P. Vincent et al, Circadian gene transcription plays a role in cellular metabolism in hibernating brown bears, Ursus arctos, Journal of Comparative Physiology B (2023). DOI: 10.1007/s00360-023-01513-5

  • Dr. Krishna Kumari Challa

    How cell identity is preserved when cells divide

    Every cell in the human body contains the same genetic instructions, encoded in its DNA. However, out of about 30,000 genes, each cell expresses only those genes that it needs to become a nerve cell, immune cell, or any of the other hundreds of cell types in the body.

    Each cell's fate is largely determined by chemical modifications to the proteins that decorate its DNA; these modification in turn control which genes get turned on or off. When cells copy their DNA to divide, however, they lose half of these modifications, leaving the question: How do cells maintain the memory of what kind of cell they are supposed to be?

    A new MIT study proposes a theoretical model that helps explain how these memories are passed from generation to generation when cells divide. The research team suggests that within each cell's nucleus, the 3D folding pattern of its genome determines which parts of the genome will be marked by these chemical modifications.

    After a cell copies its DNA, the marks are partially lost, but the 3D folding allows each daughter cell to easily restore the chemical marks needed to maintain its identity. And each time a cell divides, chemical marks allow a cell to restore its 3D folding of its genome. This way, by juggling the memory between 3D folding and the marks, the memory can be preserved over hundreds of cell divisions.

     Jeremy A. Owen et al, Design principles of 3D epigenetic memory systems, Science (2023). DOI: 10.1126/science.adg3053www.science.org/doi/10.1126/science.adg3053

  • Dr. Krishna Kumari Challa

    Researchers help reduce lead levels in Madagascar drinking water

    A team of engineers and public health experts helped residents reduce their exposure to lead—a major global environmental pollutant that causes more than 1 million premature deaths each year. By combining efforts to replace water pumps and educate city technicians, these researchers helped decrease the blood lead levels of 87 percent of the children tested during their study.

    The lead concentrations of the water from the pumps exceeded the World Health Organization's recommended limit of lead in drinking water—10 micrograms per liter. In some cases, the water contained more than 10 times the recommended limit.

    The families and children are drinking this water and using it to cook their meals.

    In low- and middle-income countries, there is a lack of regulations and understandings of the harmful effects of lead, as well as other comorbidities, such as improper nutrition, that can increase childhood lead absorption.

    The pumps are the primary source of water for more than three-quarters of the coastal area of Madagascar, where there are about 9,000 pumps because tap water is not always affordable or available for the city's 280,000 people. 

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    They used social marketing—a process that focuses on changing behavior to improve health using strategies from the commercial marketing world—to create a faster, more cost-effective plan to directly educate the people responsible for the manufacturing and repairing of the pumps.

    The researchers worked with local staff to build the capacity and skill set of technicians, while overseeing and facilitating work on the pumps to ensure they understood how to remove and replace the leaded pump components. Additionally, to understand the impact of this intervention, they worked with local health practitioners to measure blood lead levels of small children who drank water from the pumps before and after the leaded pump components were replaced.

    Of the 55 children tested, 87 percent experienced a significant decrease in blood lead levels once leaded components were removed from the pumps.

    Adaline M. Buerck et al, Reductions in Children's Blood Lead Levels from a Drinking-Water Intervention in Madagascar, Sub-Saharan Africa, Environmental Science & Technology (2023). DOI: 10.1021/acs.est.3c03774

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  • Dr. Krishna Kumari Challa

    Light, not just heat, might spur water to evaporate

    If real, the effect might be occurring naturally all over the world

    Green light means “go.” That might apply to evaporating water molecules too.

    Visible light, especially that of a greenish hue, might spur water to evaporate, researchers report in the Nov. 7 Proceedings of the National Academy of Sciences. In experiments, water evaporating under visible light showed a higher evaporation rate than possible based on heat alone.

    Coupled with other observations, they say, the finding suggests that when light shines on water, individual particles of light, or photons, can sever the bonds that connect water molecules, releasing clusters of molecules into the air.

    In the new study, the researchers shone light on water contained in porous hydrogels, materials that greedily sop up water. The proposed effect occurs where air meets water, and the hydrogels the researchers studied contain innumerable crannies where the two meet, allowing the water to be cleaved off and escape. In some cases, the evaporation rate was more than double the expectation based on heat. What’s more, the evaporation rate varied with the wavelength of the light. Green light produced the highest evaporation rate.

  • Dr. Krishna Kumari Challa

    What happens when AI eats itself?

  • Dr. Krishna Kumari Challa

    A Virus that Generates Electricity 

    Melting a bacteriophage’s coat of proteins turns it into a tiny power plant, which could fire up the discovery of new bioengineered devices.

    Our bodies are alive with electrical signals that allow us to contract muscles and sense the world. The complex brain orchestrates these processes, but it turns out that even simpler biological entities generate electricity. In a new study published in Advanced Materials, researchers reported that a bioengineered virus generated electricity when exposed to heat, a phenomenon known as pyroelectricity. By working with viruses, the researchers hope to better understand bioelectricity in the human body and apply this knowledge to power novel biomaterials.

    The M13 bacteriophage, a rod-shaped virus that infects bacteria, is adorned in a molecular coat, woven from nearly 3,000 copies of a helical protein. The protein is positively charged on the inside and negatively charged on the outside, but the arrangement of the thick protein coat balances out the charges. 

    Over a decade ago, a research team put the squeeze on the coat proteins, which caused the bacteriophage to exhibit piezoelectricity—the ability to transform mechanical force into electricity.  When the researchers applied pressure to the viruses, the coat proteins changed shape, breaking the charge symmetry and becoming polarized, which generated an electric field and induced a current.

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    In this new study,  the researchers addressed whether they could similarly use heat to shift the charge and generate electricity. They edited the genetic code of the viruses to include a specific protein sequence that is attracted to nickel. This way, the viruses would bind to and stand straight up on a thin nickel-coated plate, like a city block of skyscrapers. Then, they blasted these viral cities with heat, either with fire or a laser. As the proteins melted and unfolded, the proteins’ charges became unbalanced, generating voltage. The heat induced a polarization change, and the polarization change induced the electric potential.

    Although the naturally occurring helical protein produces some pyroelectricity, the researchers wanted to see if they could give the molecule some added spark. To do this, they genetically altered the bacteriophage to add a string of glutamate, a negatively charged building block of proteins, into the outside of the coat protein.1,4 When the researchers turned up the heat, the added glutamate amplified the polarization change, more than doubling the pyroelectricity of the normal protein.

    “The very fact that they can genetically mutate the virus and make them pyroelectric—it's fascinating work, according to some physicists.

    To demonstrate the practical applications of their supercharged virus, the research team generated electrical signatures that flag the presence of hazardous chemicals. To do this, they engineered the protein coat to bind xylene. Then when they heat blasted the bacteriophages, the proteins shapeshifted and produced more electricity. By detecting this difference in electricity, the authors say that the viruses could act as biosensors for harmful gases. 

    1. Kim H, et al. Virus-based pyroelectricity. Adv Mater. 2023;35(46):e2305503.
    2. Piccolino M. Luigi Galvani and animal electricity: Two centuries after the found.... Trends Neurosci. 1997;20(10):443-448.
    3. Lee BY, et al. Virus-based piezoelectric energy generation. Nat Nanotechnol. 2012;7(6):351-356.
    4. Lee JH, et al. Vertical self-assembly of polarized phage nanostructure for energy .... Nano Lett. 2019;19(4):2661-2667.

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  • Dr. Krishna Kumari Challa

    To kill malaria-carrying mosquitoes efficiently, just add soap!

    Could the solution to the decades-long battle against malaria be as simple as soap? In a new study published in PLOS Neglected Tropical Diseases, scientists  have made a compelling case for it.

    A research team has found that adding small quantities of liquid soap to some classes of pesticides can boost their potency by more than 10-fold. The discovery is promising news as malaria-carrying mosquitoes display an increasing resistance to current insecticides.

    Both laboratory tests and field trials have shown that neonicotinoids, a special class of insecticide, are a promising alternative to target populations showing resistance to existing insecticides. Neonicotinoids, however, do not kill some mosquito species unless their potency is boosted. In this case, the researchers say, soap is the boosting substance.

    Colince Kamdem et al, Vegetable oil-based surfactants are adjuvants that enhance the efficacy of neonicotinoid insecticides and can bias susceptibility testing in adult mosquitoes, PLoS Neglected Tropical Diseases (2023).

  • Dr. Krishna Kumari Challa

    Nanoplastics promote conditions for Parkinson's across various lab models, study shows

    Nanoplastics interact with a particular protein that is naturally found in the brain, creating changes linked to Parkinson's disease and some types of dementia.

    In a study appearing Nov. 17 in Science Advances,  researchers report that the findings create a foundation for a new area of investigation, fueled by the timely impact of environmental factors on human biology.

    Parkinson's disease has been called the fastest growing neurological disorder in the world. Numerous lines of data suggest environmental factors might play a prominent role in Parkinson's disease, but such factors have for the most part not been identified till now.

    Improperly disposed plastics have been shown to break into very small pieces and accumulate in water and food supplies, and were found in the blood of most adults in a recent study.

    This new study suggests that the emergence of micro and nanoplastics in the environment might represent a new toxin challenge with respect to Parkinson's disease risk and progression. This is especially concerning given the predicted increase in concentrations of these contaminants in our water and food supplies.

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    Researchers found that nanoparticles of the plastic polystyrene—typically found in single use items such as disposable drinking cups and cutlery—attract the accumulation of the protein known as alpha-synuclein.

    The study's most surprising findings are the tight bonds formed between the plastic and the protein within the area of the neuron where these accumulations are congregating, the lysosome.

    Researchers said the plastic-protein accumulations happened across three different models performed in the study—in test tubes, cultured neurons, and mouse models of Parkinson's disease. The questions remain about how such interactions might be happening within humans and whether the type of  plastic might play a role.

    While microplastic and nanoplastic contaminants are being closely evaluated for their potential impact in cancer and autoimmune diseases, the striking nature of the interactions the researchers could observe in their models suggest a need for evaluating increasing nanoplastic contaminants on Parkinson's disease and dementia risk and progression.

    Zhiyong Liu et al, Anionic nanoplastic contaminants promote Parkinson's disease–associated α-synuclein aggregation, Science Advances (2023). DOI: 10.1126/sciadv.adi8716www.science.org/doi/10.1126/sciadv.adi8716

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  • Dr. Krishna Kumari Challa

    No evidence for widespread transmission of viruses by African bats, says study

    The scientific community and the public alike have often been presented with portrayals of bats as carriers of numerous dangerous viruses that are passed onto humans. In a paper published in Biology Letters, an international team of biologists, virologists and conservationists challenge this narrative surrounding bats.

    Contrary to widely held beliefs, this comprehensive review of published studies finds no evidence, outside of Marburg and Sosuga virus, that African bat species serve as reservoirs or bridging hosts for viruses that spillover to humans and cause significant disease.

    The research team,  examined the available literature, specifically focusing on viruses detected in bats in Africa. They meticulously reviewed 162 papers published between 1978 and 2020 and, based on data from more than 80,000 individual bats from 167 bat species, did not find substantial evidence that any bat species, other than the Egyptian rousette, plays a central role in the transmission of viruses to humans in this region.

    The researchers found no evidence to support the prevailing narrative that bats harbour viruses that are transmitted to humans. On the contrary, their findings reveal only two bat-virus systems in which transmission is clearly documented.

    The findings highlight the need for a more nuanced and informed approach to public discourse surrounding the role of wildlife in disease emergence." The authors thus propose a scheme to aid standardized evaluation of virus hosts in the future and call for greater interdisciplinary collaborations in bat-virus studies.

    The researchers also state that instead of broadly stating bats harbour the Marburg virus, it is more accurate to specify that the Egyptian rousette, a specific bat species, hosts the Marburg virus. This phrasing preserves accuracy and avoids incorrectly associating all bat species with the Marburg virus.

    This  will contribute to a more accurate understanding of the complex dynamics between wildlife, particularly bats, and human health.

    Their study also raises concerns about the impact of reiterated research communication linking bats and viruses, based on missing evidence, on the public perception of bats, as well as human-bat conflicts and bat conservation efforts. Fear and active prosecution of bats are increasing dramatically and it is likely that populations are declining.

     Careful and scientifically sound communication of results as well as balancing potential risks against benefits will be crucial to allow humans and bats to live side by side in our changing world. The implications of this research extend beyond Africa, encouraging a more thoughtful and evidence-based approach to the study of zoonotic diseases worldwide.

     Natalie Weber et al, Robust evidence for bats as reservoir hosts is lacking in most African virus studies: a review and call to optimize sampling and conserve bats, Biology Letters (2023). DOI: 10.1098/rsbl.2023.0358

  • Dr. Krishna Kumari Challa

    For The First Time, an Eerie Green Glow Has Been Detected in The Night Sky of Mars

    For the first time, a soft green glow has been detected in the night sky of Mars that we'd be able to see with our human eyes.

    As it orbits Mars, the European Space Agency's (ESA) ExoMars Trace Gas Orbiter mission has spotted the Martian night sky glowing in light in the optical spectrum.

    And the light is so bright in the polar regions that human explorers might even be able to use it to see, if the night is clear of clouds. These observations are unexpected and interesting for future trips to the Red Planet.

    Actually, nightglow is a relatively common phenomenon in the atmospheres of the Solar System. A number of things can cause our atmosphere to emit its own light at night, but few things more than our own Sun. During the day, sunlight splits apart molecules in a process called photodissociation. However, on the night side of the atmosphere, away from the harsh radiation of the Sun, the loose atoms can recombine into molecules, releasing their excess energy as photons as they do so.

    Here on Earth, the nightglow is visible from space as layers of green, golden, and even reddish light, depending on the molecules involved.

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    But on other planets, things are a little less spectacular, at least to human eyes. The nightglow on Venus is infrared. On Jupiter, the glow is more ultraviolet (and apparently variable).

    On Mars, infrared and ultraviolet nightglow have been seen. Scientists have even seen dayglow caused by the atmospheric absorption and release of energy from solar radiation in the visible spectrum on Mars (although you wouldn't be able to see it yourself, as a Mars explorer; daylight is simply too bright).

    But "No nightglow spectrum has been observed so far in the visible domain," the researchers write. "Scattered solar light hinders such measurements from Earth's ground and no space-borne instrument has observed the Mars visible nightglow."
    Between altitudes of 40 and 60 kilometers (25 to 37 miles), visible nightglow was spotted at the south pole during its Martian winter.

    This, the researchers say, is the result of oxygen atoms transported from the sunny Martian day combining into dioxygen (O2), emitting a glow in the process – one bright enough to be seen from the ground.

    This O2 nightglow should be observable from a Martian orbiter as well as from the Martian surface with the naked eye under clear sky conditions," the researchers write.

    https://www.nature.com/articles/s41550-023-02104-8

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  • Dr. Krishna Kumari Challa

    New research maps 14 potential evolutionary dead ends for humanity and ways to avoid them

    For the first time, scientists have used the concept of evolutionary traps on human societies at large. They find that humankind risks getting stuck in 14 evolutionary dead ends, ranging from global climate tipping points to misaligned artificial intelligence, chemical pollution, and accelerating infectious diseases.

    The evolution of humankind has been an extraordinary success story. But the Anthropocene—the proposed geological epoch shaped by us humans—is showing more and more cracks. Multiple global crises, such as the COVID-19 pandemic, climate change, food insecurity, financial crises, and conflicts have started to occur simultaneously in something which scientists refer to as a polycrisis.

    Humans are incredibly creative as a species. We are able to innovate and adapt to many circumstances and can cooperate on surprisingly large scales. But these capabilities turn out to have unintentional consequences. Simply speaking, you could say that the human species has been too successful and, in some ways, too smart for its own future good.

    The  new study published as part of a larger assessment in the journal Philosophical Transactions of the Royal Society B. The assessment gathers insights from a wide range of different scientific disciplines across the natural and social sciences and humanities, to understand how the Anthropocene evolved and how global sustainability can continue to evolve in the future.

    The new study shows how humanity could get stuck in "evolutionary traps"—dead ends that occur from initially successful innovations. In a first scoping effort, they identify 14 of these, including the simplification of agriculture, economic growth that does not deliver benefits for humans or the environment, the instability of global cooperation, climate tipping points, and artificial intelligence.

    Evolutionary traps are a well-known concept in the animal world. Just like many insects are attracted by light, an evolutionary reflex that can get them killed in the modern world, humankind is at risk of responding to new phenomena in harmful ways.

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    The simplification of agricultural systems is an example of such a trap. Relying on a few highly productive crops such as wheat, rice, maize, and soya, has meant that calories produced have skyrocketed over the past century. But it also meant that the food system has become very vulnerable to environmental change, such as weather extremes, or new diseases.

    Of the 14 evolutionary traps, 12 are in an advanced state, meaning that humankind is on the verge of getting stuck to a degree where it becomes very difficult to get out. What's more, societies are continuing to move in the wrong direction in 10 of these 14.

    Alarmingly, these evolutionary traps tend to reinforce each other. If societies get stuck in one dead end, they are more likely to get stuck in others as well. The two dead ends which currently are less advanced are the autonomy of technology—AI and robotics—and a loss of social capital through digitalization.

    The new assessment also looks into why societies struggle so hard to move out of these traps.

    The evolutionary forces that created the Anthropocene do not work well at the global level. In today's global systems, social and environmental problems grow in places that seem distant to the societies that could prevent them. Also, addressing them often requires global collaboration on a scale that many evolutionary forces often do not align well with.

    This does not mean that humanity is doomed to fail, argue the researchers. But we must start to transform our societies actively. So far, the Anthropocene has to a large extent been an unconscious byproduct of other evolutionary processes.

    "It's time for humans to become aware of the new reality and to collectively move where we want to as a species. We have the capability to do that and are already seeing signs of such movements. Our creativity, and our power to innovate and collaborate equip us with the perfect tools to actively design our future. We can break out of dead ends and business-as-usual, but for that, we must nurture the capacity for collective human agency and design settings where it can flourish.

    A very simple thing that everybody can do is to engage more in nature and society while also learning about both the positive and negative global consequences of our own local actions.

     Peter Søgaard Jørgensen et al, Evolution of the polycrisis: Anthropocene traps that challenge global sustainability, Philosophical Transactions of the Royal Society of London (B ) (2023). DOI: 10.1098/rstb.2022.0261

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    (a) System dynamics associated with three major groups of Anthropocene traps, global traps, technology traps and structural traps (including temporal and connectivity traps). Two reinforcing feedback loops are indicated with R and interactions between dynamics across groups oftraps are indicated with colored superscript letters (color of causal node) and stippled lined arrows. Credit: Philosophical Transactions of the Royal Society B

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  • Dr. Krishna Kumari Challa

    Early-life stress changes more genes in the brain than a head injury

    A surprising thing happened when researchers began exploring whether early-life stress compounds the effects of a childhood head injury on health and behavior later in life. In an animal study, stress changed the activation level of many more genes in the brain than were changed by a bump to the head.

    It's already known that head injuries are common in young kids, especially from falling, and can be linked to mood disorders and social difficulties that emerge later in life. Adverse childhood experiences are also very common, and can raise risk for disease, mental illness and substance misuse in adulthood.

    Researchers found many, many, many more genes were differentially expressed as a result of their early life stress manipulation than their traumatic brain injury manipulation in animals.

    Stress is really powerful, and we shouldn't understate the impact of early life stress on the developing brain, according to them. 

    The research poster was presented Nov. 12, 2023 at Neuroscience 2023, the annual meeting of the Society for Neuroscience.

    https://www.sfn.org/meetings/neuroscience-2023

  • Dr. Krishna Kumari Challa

    Brightest flash ever disturbed Earth's atmosphere last year

    Last year the brightest flash of light ever seen in the night sky disturbed Earth's upper atmosphere in a way that has never before detected before.

    A massive burst of gamma rays from an enormous cosmic explosion around two billion light years away arrived at Earth on October 9, 2022, lighting up telescopes around the world.

    Quickly nicknamed the "BOAT"—for Brightest Of All Time—the flash lasted just seven minutes but its afterglow was visible to amateur astronomers for seven hours.

    The flash activated lightning detectors in India and triggered instruments that normally study explosions on the sun called solar flares. It also affected long wave radio communications in the lower ionosphere, a section of Earth's upper atmosphere around 60 to 350 kilometers (37 to 217 miles) above the surface. The BOAT also affected the upper ionosphere—the very first time a gamma-ray burst has been observed in this section of the atmosphere.

    From 350 to 950 kilometers above Earth, near the edge of the space, the upper ionosphere is where radiation from the sun turns into charged particles that form an important electric field.

    Researchers found a shape in the electric field that had never been observed before.

    The research would help scientists understand the potential threat that other gamma-ray bursts could pose in the future. The worst-case scenario would be if such a powerful blast came from much closer to home—say, within our own Milky Way galaxy. That could "completely erase" Earth's ozone layer.

    This would expose everything on the surface to the full might of the sun's ultraviolet radiation, potentially wiping out life on Earth. There has previously been speculation that past gamma-ray bursts could have caused ancient mass extinction events.

    But It is also possible that the ionosphere would absorb all the gamma rays and "nothing would happen" to those of us on the ground.

    The blast came from the direction of the constellation Sagitta and traveled an estimated 1.9 billion years to reach Earth. It is now 2.4 billion light years away because of the expansion of the universe. On average, more than one gamma-ray-burst reaches Earth every day. But one with the brightness of the BOAT is estimated to come around once every 10,000 years.

    Mirko Piersanti, Evidence of an upper ionospheric electric field perturbation correlated with a gamma ray burst, Nature Communications (2023). DOI: 10.1038/s41467-023-42551-5www.nature.com/articles/s41467-023-42551-5

  • Dr. Krishna Kumari Challa

    Why does even a small amount of red wine give some people headaches?

     For some people, drinking red wine even in small amounts causes a headache. Typically, a "red wine headache" can occur within 30 minutes to three hours after drinking as little as a small glass of wine.

    In a new study, scientists examined why this happens—even to people who don't get headaches when drinking small amounts of other alcoholic beverages. Researchers think that a flavanol found naturally in red wines can interfere with the proper metabolism of alcohol and can lead to a headache. The study was published in the journal Scientific Reports.

    This flavanol is called quercetin and it is naturally present in all kinds of fruits and vegetables, including grapes. It's considered a healthy antioxidant and is even available in supplement form. But when metabolized with alcohol, it can be problematic.

    When it gets in your bloodstream, your body converts it to a different form called quercetin glucuronide. In that form, it blocks the metabolism of alcohol. As a result, people can end up accumulating the toxin acetaldehyde. Acetaldehyde is a well-known toxin, irritant and inflammatory substance. Researchers know that high levels of acetaldehyde can cause facial flushing, headache and nausea.

    The medication disulfiram prescribed to alcoholics to prevent them from drinking causes these same symptoms. That's because the drug also causes the toxin to build up in the body when normally an enzyme in the body would break it down. About 40% of the East Asian population also has an enzyme that doesn't work very well, allowing acetaldehyde to build up in their system.

     When susceptible people consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a preexisting migraine or another primary headache condition.

    Part 1

  • Dr. Krishna Kumari Challa

    Levels of this flavanol can vary dramatically in red wine

    Quercetin is produced by the grapes in response to sunlight. If you grow grapes with the clusters exposed, such as they do in the Napa Valley for their cabernets, you get much higher levels of quercetin. In some cases, it can be four to five times higher.

    Levels of quercetin can also differ depending on how the wine is made, including skin contact during fermentation, fining processes and aging.

    Scientists are testing this hypothesis  now .

     Inhibition of ALDH2 by Quercetin Glucuronide Suggests a New Hypothesis to Explain Red Wine Headaches, Scientific Reports (2023).

    Part 2

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