Science Simplified!

                       JAI VIGNAN

All about Science - to remove misconceptions and encourage scientific temper

Communicating science to the common people

'To make  them see the world differently through the beautiful lense of  science'

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  • Dr. Krishna Kumari Challa

    Stolen bacterial genes defeat fungus

    Microscopic freshwater animals, just half a millimetre long, have perfected the trick of stealing genes from bacteria, allowing them to fight off infections and survive for millions of years without sex. These unusual creatures, bdelloid rotifers, are all females and 10% of their genes come from foreign organisms. Asexual reproduction should leave them vulnerable to pathogens but some of the ‘borrowed genes’ code for bacterial enzymes known as synthetases, w... — helping the rotifers to defeat fungal infections.

    https://www.nature.com/articles/s41467-024-49919-1?utm_source=Live+...

  • Dr. Krishna Kumari Challa

    Hungry fungi clean up contamination

    A growing number of biotech companies are investing in fungal treatments that break down environmental contaminants — from.... Fungi tend to be better than bacteria at tackling large, complex chemicals like the hydrocarbons in many plastics, although this sometimes requires combining different strains of fungi to perform different steps of the process. They can be applied directly to contaminated soil or water, as well as used to break down plastic-based garbage like carpets or mattresses.

    https://www.nature.com/articles/s41587-024-02315-y.epdf?sharing_tok...

  • Dr. Krishna Kumari Challa

    Scientists figure out why there are so many colorful birds in the tropics and how these colours spread over time

    The color palette of the birds you see out your window depends on where you live. If you're far from the Equator, most birds tend to have drab colors, but the closer you are to the tropics, you'll probably see more and more colorful feathers.

    Scientists have long been puzzled about why there are more brilliantly-colored birds in the tropics than in other places, and they've also wondered how those brightly-colored birds got there in the first place: that is, if those colorful feathers evolved in the tropics, or if tropical birds have colorful ancestors that came to the region from somewhere else.

    In a study published in the journal Nature Ecology and Evolution, scientists built a database of 9,409 birds to explore the spread of color across the globe.

    They found that iridescent, colorful feathers originated 415 times across the bird tree of life, and in most cases, arose outside of the tropics– and that the ancestor of all modern birds likely had iridescent feathers, too.

    There are two main ways that color is produced in animals: pigments and structures. Cells produce pigments like melanin, which is responsible for black and brown coloration. Meanwhile, structural color comes from the way light bounces off different arrangements of cell structures. Iridescence, the rainbow shimmer that changes depending how light hits an object, is an example of structural colour.

    Tropical birds get their colors from a combination of brilliant pigments and structural color.

    Researchers  combed through photographs, videos, and even scientific illustrations of 9,409 species of birds— the vast majority of the 10,000-ish living bird species known to science. The researchers kept track of which species have iridescent feathers, and where those birds are found.

    The scientists then combined their data on bird coloration and distribution with a pre-existing family tree, based on DNA, showing how all the known bird species are related to each other. They fed the information to a modeling system to extrapolate the origins and spread of iridescence.

    Given how modern species are related to each other and where they're found, and overall patterns of how species form and how traits like colors change over time, the modeling software determined the most likely explanation for the bird colors we see today: colorful birds from outside the tropics often came to the region millions of years ago, and then branched out into more and more different species. The model also revealed a surprise about the ancestor of all modern birds.

    Part 1

  • Dr. Krishna Kumari Challa

    Birds are a specialized group of dinosaurs— the earliest known bird, Archaeopteryx, lived 140 million years ago. A sub-group of birds called Neornithes evolved 80 million years ago, and this group became the only birds (and dinosaurs) to survive the mass extinction 66 million years ago.
    All modern birds are members of Neornithes.The model produced by researchers now suggests that the common ancestor of all Neornithes, 80 million years ago, had iridescent feathers that still glitter across the bird family tree.
    Researchers found fossil evidence of iridescent birds and other feathered dinosaurs before, by examining fossil feathers and the preserved pigment-producing structures in those feathers. So we know that iridescent feathers existed back in the Cretaceous—those fossils help support the idea from this new model that the ancestor of all modern birds was iridescent too.
    The discovery that the first Neornithes was likely iridescent could have important implications for paleontology.

    Transitions between colour mechanisms affect speciation dynamics and range distributions of birds, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02487-5

    Part 2

  • Dr. Krishna Kumari Challa

    Ice 0: Researchers discover a new mechanism for ice formation

    Ice is far more complicated than most of us realize, with over 20 different varieties known to science, forming under various combinations of pressure and temperature. The kind we use to chill our drinks is known as ice I, and it's one of the few forms of ice that exist naturally on Earth.

    Researchers have recently discovered another type of ice: ice 0, an unusual form of ice that can seed the formation of ice crystals in supercooled water.

    The formation of ice near the surface of liquid water can start from tiny crystal precursors with a structure similar to a rare type of ice, known as ice 0.

    In a study published in Nature Communications, researchers showed that these ice 0-like structures can cause a water droplet to freeze near its surface rather than at its core. This discovery resolves a longstanding puzzle and could help redefine our understanding of how ice forms.

    Crystallization of ice, known as ice nucleation, usually happens heterogeneously, or in other words, at a solid surface. This is normally expected to happen at the surface of the water's container, where liquid meets solid.

    However, this new research shows that ice crystallization can also occur just below the water's surface, where it meets the air. Here, the ice nucleates around small precursors with the same characteristic ring-shaped structure as ice 0.

    Simulations have shown that a water droplet is more likely to crystallize near the free surface under isothermal conditions. This resolves a longstanding debate about whether crystallization occurs more readily on the surface or internally.

    Ice 0 precursors have a structure very similar to supercooled water, allowing water molecules to crystallize more readily from it, without needing to directly form themselves into the structure of regular ice.

    The tiny ice 0 precursors are formed spontaneously, as a result of negative pressure effects caused by the surface tension of water. Once crystallization begins from these precursors, structures similar to ice 0 quickly rearrange themselves into the more familiar ice I.

    Surface-induced water crystallization driven by precursors formed in negative pressure regions, Nature Communications (2024). DOI: 10.1038/s41467-024-50188-1

  • Dr. Krishna Kumari Challa

    New aerospace and building materials could repair themselves thanks to fungi and bacteria

    Researchers are using biological matter to create unique new materials that can adapt to their environment and repair themselves.

    Researchers are developing what they call "living materials," for use in the aerospace and transportation sectors. These living materials are, precisely as they sound, literally alive. They contain microorganisms such as fungi and bacteria, which give them the capacity to sustain their integrity and self-healing.

    The goal is to make engineered structures that can behave like living organisms, able to sense and adapt to mechanical stresses.

    The material they are developing is a composite that combines living fungi cells and wood. It consists of a hydrogel and mycelium, a root-like structure of a fungus that normally lives underground.

    They chose to work with fungi because fungus is a really robust organism, it is tolerant to harsh conditions and is relatively easy to cultivate. 

    Moreover, fungal cells have a great ability to connect. Mycelium can grow a vast sensing network that allows it to send signals throughout the organism. That means the scientists can distribute only a few cells throughout the material, and these cells will reconnect and form a sensing network.

    Biological materials could help to improve the performance and durability of critical structures used in areas like aerospace and transportation.

    These materials are very lightweight and more sustainable than currently used materials. 

    Sources: 

  • Dr. Krishna Kumari Challa

    Scientists control bacterial mutations to preserve antibiotic effectiveness

    Scientists have discovered a way to control mutation rates in bacteria, paving the way for new strategies to combat antibiotic resistance.

    Antibiotics are given to kill bad bacteria; however, with just one mutation a bacteria can evolve to become resistant to that antibiotic, making common infections potentially fatal.

    The new research, published recently in the journal PLOS Biology, used high-performance computing to simulate more than 8,000 years of bacterial evolution, allowing scientists to predict mechanisms that control mutation rates.

    They then made more than 15,000 cultures of E. coli in lab conditions to test their predictions—that's so many that if you lined up all of the bacteria in this study, they would stretch 860,000 km, or wrap around the Earth more than 20 times.

    The tests revealed that bacteria living in a lowly populated community are more prone to developing antibiotic resistance due to a naturally occurring DNA-damaging chemical, peroxide. In crowded environments, where cells are more densely packed, bacteria work collectively to detoxify peroxide, reducing the likelihood of mutations that lead to antibiotic resistance.

    The finding could help develop "anti-evolution drugs" to preserve antibiotic effectiveness by limiting the mutation rates in bacteria.

    By understanding the environmental conditions that influence mutation rates, we can develop strategies to safeguard antibiotic effectiveness. This new study shows that bacterial mutation rates are not fixed and can be manipulated by altering their surroundings, which is vital on our journey to combat antibiotic resistance.

    Peroxide, a chemical found in many environments, is key to this process. When E. coli populations become denser, they work together to lower peroxide levels, protecting their DNA from damage and reducing mutation rates. The study showed that genetically modified E. coli that is unable to break down peroxide had the same mutation rates, no matter the population size. However, when helper cells that could break down peroxide were added, the mutation rate in these genetically modified E. coli decreased.

    Rowan Green et al, Collective peroxide detoxification determines microbial mutation rate plasticity in E. coli, PLOS Biology (2024). DOI: 10.1371/journal.pbio.3002711

  • Dr. Krishna Kumari Challa

    Komodo Dragon Teeth Have Iron Caps For Sharpness, Scientists Discover

    As if komodo dragons weren't amazing enough, these giant lizards literally have teeth of iron.

    A new study of these formidable predators' chompers has revealed concentrated deposits of iron along the serrated tearing edges and the tips of their teeth, helping to keep them razor-sharp for tearing the flesh from the prey they devour.

    Although many vertebrates have iron enhancements in their teeth, komodo dragons (Varanus komodoensis) and other similar species with serrated teeth, called ziphodonts, represent the most striking examples found to date.
    In fact, so much iron is concentrated along the sharp edges of komodo teeth that they are tinted orange.

    Never before has iron been found so localized along the cutting edge of a vertebrate tooth. This suggests that a stronger cutting edge confers a competitive advantage, and may yield insights into how some of the fiercest dinosaurs devoured their food.

    https://www.nature.com/articles/s41559-024-02477-7

  • Dr. Krishna Kumari Challa

    Biologists discover human-infecting parasite produces sterile soldiers like ants and termites

    New research from scientists finds a tiny freshwater parasite known to cause health problems in humans defends its colonies with a class of soldiers that cannot reproduce.


    The discovery, published in the Proceedings of the National Academy of Sciences vaults this species of parasitic flatworm into the ranks of complex animal societies such as ants, bees and termites, which also have distinct classes of workers and soldiers that have given up reproduction to serve their colony.

    When it gets into humans, usually via the consumption of raw or undercooked fish, this species of flatworm, Haplorchis pumilio, can cause gastrointestinal issues and, in severe cases, stroke or heart attack. Fully cooking fish or freezing any meant to be eaten raw for at least one week is enough to kill the trematodes, per Food and Drug Administration guidelines.

    While there are no specific statistics for Haplorchis pumilio, foodborne trematode infections cause 2 million life years lost to disability and death worldwide every year.

    Unlike bees and termites, the colonies of this species of flatworm are not underground or in a tree hollow, but inside the body of a live snail. The parasites don't kill the snail, but instead siphon off nutrients for years as they pump out free-swimming clones that search for fish, the flatworms' next host in their complex life cycle.

    These flatworms could become invaluable tools to probe fundamental questions of sociobiology—like, 'how does this kind of social organization evolve?

    This study is the first evidence for trematode soldiers that are so physically specialized to their task that they lack any reproductive tissues and appear permanently incapable of reproduction.

     Daniel C. G. Metz et al, The physical soldier caste of an invasive, human-infecting flatworm is morphologically extreme and obligately sterile, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2400953121

  • Dr. Krishna Kumari Challa

    Neuroscientists discover brain circuitry of placebo effect for pain relief

    The placebo effect is very real. Some placebo effects are so strong that individuals are convinced they received a real treatment meant to help them. This we've known for decades, as seen in real-life observations and the best double-blinded randomized clinical trials researchers have devised for many diseases and conditions, especially pain. And yet, how and why the placebo effect occurs has remained a mystery. Now, neuroscientists have discovered a key piece of the placebo effect puzzle.
     And the placebo effect—feeling better even though there was no "real" treatment—has been documented as a very real phenomenon for decades.

    It is the human experience, in the face of pain, to want to feel better. As a result—and in conjunction with millennia of evolution—our brains can search for ways to help us feel better.

    It releases chemicals, which can be measured.

    Published now in Nature, researchers discovered a pain control pathway that links the cingulate cortex
     in the front of the brain, through the pons region of the brainstem, to cerebellum in the back of the brain.
    They showed that certain neurons and synapses along this pathway are highly activated when mice expect pain relief and experience pain relief, even when there is no medication involved.
    That neurons in our cerebral cortex communicate with the pons and cerebellum to adjust pain thresholds based on our expectations is both completely unexpected, given our previous understanding of the pain circuitry, and incredibly exciting. These results do open the possibility of activating this pathway through other therapeutic means, such as drugs or neurostimulation methods to treat pain.
    This research provides a new framework for investigating the brain pathways underlying other mind-body interactions and placebo effects beyond the ones involved in pain.
    Grégory Scherrer, Neural circuit basis of placebo pain relief, Nature (2024). DOI: 10.1038/s41586-024-07816-zwww.nature.com/articles/s41586-024-07816-z
  • Dr. Krishna Kumari Challa

    Signs of Ancient Life on Mars?

    NASA’s Perseverance rover has made very compelling observations in a Martian rock that, with further study, could prove that life was present on Mars in the distant past – but how can we determine that from a rock, and what do we need to do to confirm it? Morgan Cable, a scientist on the Perseverance team, takes a closer look.

  • Dr. Krishna Kumari Challa

    Trees reveal climate surprise: Microbes living in bark remove methane from the atmosphere

    Tree bark surfaces play an important role in removing methane gas from the atmosphere, according to a study published 24 July in Nature.

    While trees have long been known to benefit the climate by removing carbon dioxide from the atmosphere, this new research reveals a surprising additional climate benefit. Microbes hidden within tree bark can absorb methane—a powerful greenhouse gas—from the atmosphere.

    An international team of researchers has shown for the first time that microbes living in bark or in the wood itself are removing atmospheric methane on a scale equal to or above that of soil. They calculate that this newly discovered process makes trees 10% more beneficial for climate overall than previously thought.

    Methane is responsible for around 30% of global warming since pre-industrial times and emissions are currently rising faster than at any point since records began in the 1980s.

    Although most methane is removed by processes in the atmosphere, soils are full of bacteria that absorb the gas and break it down for use as energy. Soil had been thought of as the only terrestrial sink for methane, but researchers now show that trees may be as important, perhaps more so.

    Vincent Gauci, Global atmospheric methane uptake by upland tree woody surfaces, Nature (2024). DOI: 10.1038/s41586-024-07592-wwww.nature.com/articles/s41586-024-07592-w

  • Dr. Krishna Kumari Challa

    New study links brain microstructure to gender differences in mental health

    A team of neuroscientists and behavioral specialists has found differences between male and female brain structure in areas associated with decision-making, memory processing and handling emotions.

    In their study, published in the Proceedings of the National Academy of Sciences, the group compared more than 1,000 brain scans to better understand why men and women are more prone to different kinds of brain illness.

    Prior research has shown that male babies are three times as likely to be diagnosed with autism as they grow older than are female babies—they are also twice as likely to be diagnosed with ADHD. On the other hand, female babies are almost twice as likely to be diagnosed with anxiety or mood disorders later in life than are boys.

    Mental health specialists have wondered for many years why there are differences, and many suspect that it is due to physical brain differences between the genders. The research team thinks they may have found evidence for such differences.

    To spot possible gender differences in the brain, the researchers focused their attention on subcortical gray matter regions that prior researchers have associated with mental health, including the amygdala and the thalamus. They then analyzed MRI scans of 1,065 male and female brains, looking for differences in brain microstructure, such as the way cells are concentrated, their arrangement or even their physical characteristics.

    The research team found what they describe as "large, sex-related differences in microstructures." They noted that such changes were still apparent after adjusting for age and the relative size of the brains under study. They also found diffusion metrics in the amygdala and thalamus that they believe could be associated with mental disorders such as anxiety, ADHD, social skills issues and depression.

    They suggest that further study of diffusion MRI imagery could provide more insight into gender-based brain disorders.

    Richard Watts et al, Sex and mental health are related to subcortical brain microstructure, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2403212121www.pnas.org/doi/full/10.1073/pnas.2403212121

  • Dr. Krishna Kumari Challa

    NASA streams first 4K video from aircraft to space station and back

    A team at NASA's Glenn Research Center in Cleveland has streamed 4K video footage from an aircraft to the International Space Station and back for the first time using optical (laser) communications. The feat was part of a series of tests on new technology that could provide live video coverage of astronauts on the moon during the Artemis missions.

    Historically, NASA has relied on radio waves to send information to and from space. Laser communications use infrared light to transmit 10 to 100 times more data faster than radio frequency systems.

    Working with the Air Force Research Laboratory and NASA's Small Business Innovation Research program, Glenn engineers temporarily installed a portable laser terminal on the belly of a Pilatus PC-12 aircraft. They then flew over Lake Erie, sending data from the aircraft to an optical ground station in Cleveland. From there, it was sent over an Earth-based network to NASA's White Sands Test Facility in Las Cruces, New Mexico, where scientists used infrared light signals to send the data.

    The signals traveled 22,000 miles away from Earth to NASA's Laser Communications Relay Demonstration (LCRD), an orbiting experimental platform. The LCRD then relayed the signals to the ILLUMA-T (Integrated LCRD LEO User Modem and Amplifier Terminal) payload mounted on the orbiting laboratory, which then sent data back to Earth. During the experiments, High-Rate Delay Tolerant Networking (HDTN), a new system developed at Glenn, helped the signal penetrate cloud coverage more effectively.


  • Dr. Krishna Kumari Challa

    After each flight test, the team continuously improved the functionality of their technology.

    Source: NASA

    Part 2

  • Dr. Krishna Kumari Challa

    Blood thinner stops cobra venom
    A common blood thinner can fight the toxins in cobra venom, potentially preventing limb amputations caused by snakebites. Using the genetic editing tool CRISPR, researchers found that eliminating certain sugars on the outside of human cells allowed the cells to resist cobra toxins. In experiments with mice, a class of drugs known as heparinoids soaked up the toxin and shrank venom-induced wounds by 94%. The drugs worked against several cobra species’ venoms, but not against viper venoms.

    https://www.science.org/doi/10.1126/scitranslmed.adk4802?utm_source...

  • Dr. Krishna Kumari Challa

    A passive, renewable, more efficient way to extract water from the atmosphere

    Freshwater scarcity affects  billions of people in the world, primarily in arid and remote regions, as well as islands and coastal areas without freshwater sources. Climate change and population growth are only making the problem worse, and existing methods require an energy input, usually electrical.

    Renewable energy can fix this and is required for these regions for drinking water and irrigation, using water extracted from the atmosphere.

    It is estimated the atmosphere holds about 13 trillion tons of water, six times the freshwater in the globe's rivers; global warming allows the air to hold more water vapor, by a theoretical 7% per degree Celsius of warming.

    Now engineers and scientists  have created a system that uses  solar energy to extract as much as 3 liters (0.8 gallons) of water per square meter per day from air, in a purely passive way, requiring no maintenance or human operators. The study is published in the journal Nature Communications.

    Existing solar-driven atmospheric water extraction (SAWE) systems typically rely on absorbing water vapor from the air. When the absorbing material reaches saturation, the system is sealed and exposed to sunlight, which begins the release of the captured water. They are an improvement over passive atmospheric water technologies such as fog and dew collection, and more available in other geographies and sites with climate constraints.

    To design a passive, efficient, easily scalable and minimal-labor system, the group used a structure of multiple vertical microchannels, called mass transport bridges. The tubes, sitting in a container, are filled with a liquid salt solution that acts as a liquid absorber; they used lithium chloride.

    Depending on the temperature distribution, the ambient temperature region, exposed to the environment, continuously captures atmospheric water and stores it in a container. When the system receives sunlight, the absorber converts the light into heat and generates concentrated water vapor in the high-temperature region.

    The water vapor condenses on the chamber wall, producing freshwater. More captured water from the absorber's container moves uninterrupted to the high-temperature region.

    At the same time, the concentrated liquid in the high-temperature region is transported back to the ambient temperature region via diffusion—the movement of molecules from a region of high concentration to low concentration—and by convection—the movement of the hotter, lower density solution through the colder, denser regions—enabling continuous capture of water vapor as long as sunlight is available.

    Kaijie Yang et al, A solar-driven atmospheric water extractor for off-grid freshwater generation and irrigation, Nature Communications (2024). DOI: 10.1038/s41467-024-50715-0

  • Dr. Krishna Kumari Challa

    Virus that causes COVID-19 is widespread in wildlife

    SARS-CoV-2, the virus responsible for COVID-19, is widespread among wildlife species, according to  new research published July 29, 2024 in Nature Communications. The virus was detected in six common backyard species, and antibodies indicating prior exposure to the virus were found in five species, with rates of exposure ranging from 40 to 60% depending on the species.

    Genetic tracking in wild animals confirmed both the presence of SARS-CoV-2 and the existence of unique viral mutations with lineages closely matching variants circulating in humans at the time, further supporting human-to-animal transmission, the study found.

    The highest exposure to SARS CoV-2 was found in animals near hiking trails and high-traffic public areas, suggesting the virus passed from humans to wildlife, according to scientists.

    The findings highlight the identification of novel mutations in SARS-CoV-2 in wildlife and the need for broad surveillance, researchers say. These mutations could be more harmful and transmissible, creating challenges for vaccine development.

    The scientists stressed, however, that they found no evidence of the virus being transmitted from animals to humans, and people should not fear typical interactions with wildlife.

    Widespread exposure to SARS-CoV-2 in wildlife communities, Nature Communications (2024). DOI: 10.1038/s41467-024-49891-w

  • Dr. Krishna Kumari Challa

    Losing a loved one may speed up aging, study finds

    Losing someone close, like a family member, can make you age faster, says a new study.

    The study found that people who lost a parent, partner, sibling, or child, showed signs of older biological age compared to those who hadn't experienced such losses. The research was published in JAMA Network Open.

    Biological aging is the gradual decline in how well your cells, tissues, and organs function, leading to a higher risk of chronic diseases. Scientists measure this type of aging using DNA markers known as epigenetic clocks.

    The study suggests that the impact of loss on aging can be seen long before middle age and may contribute to health differences among racial and ethnic groups.

    The study also confirmed that people who experienced two or more losses had older biological ages according to several epigenetic clocks. Experiencing two or more losses in adulthood was more strongly linked to biological aging than one loss and significantly more so than no losses.

    Losing a parent or sibling early in life can be very traumatic, often leading to mental health issues, cognitive problems, higher risks of heart disease, and a greater chance of dying earlier. Losing a close family member at any age poses health risks, and repeated losses can increase the risks of heart disease, mortality, and dementia; and impacts may persist or become apparent long after the event.

    Familial Loss of a Loved One and Biological Aging, JAMA Network Open (2024).

     https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2821615

  • Dr. Krishna Kumari Challa

    Origins of matter in the early universe

    The early universe was 250,000 times hotter than the core of our sun. That's far too hot to form the protons and neutrons that make up everyday matter. Scientists recreate the conditions of the early universe in particle accelerators by smashing atoms together at nearly the speed of light.

    Measuring the resulting shower of particles allows scientists to understand how matter formed. The particles that scientists measure can form in various ways: from the original soup of quarks and gluons or from later reactions.

    These later reactions began 0.000001 seconds after the Big Bang, when the composite particles made of quarks began to interact with each other.

    A new calculation determined that as much as 70% of some measured particles are from these later reactions, not from reactions similar to those of the early universe. The research is published in the journal Physics Letters B.

    This finding improves scientific understanding of the origins of matter. It helps identify how much of the matter around us formed in the first few fractions of a second after the Big Bang, versus how much matter formed from later reactions as the universe expanded.

    This result implies large amounts of the matter around us formed later than expected. To understand the results of collider experiments, scientists must discount the particles formed in the later reactions.

    Only those formed in the subatomic soup reveal the early conditions of the universe. This new calculation shows that the number of measured particles formed in reactions is much higher than expected.

    Joseph Dominicus Lap et al, Hadronic J/ψ regeneration in Pb+Pb collisions, Physics Letters B (2023). DOI: 10.1016/j.physletb.2023.138246

  • Dr. Krishna Kumari Challa

    Don't close your borders: Countries need to cooperate on migration as climate crisis worsens

    Humanity must rethink migration as the climate crisis drives rapid global changes, researchers say.

    With significant migration expected—and border policies hardening—the researchers say the "time is ripe to highlight the benefits of collaboration between nations and regions."

    By promoting the benefits of migration, especially in an era of aging populations, global leaders could ensure a better future for people and societies.

    The paper, titled "Anticipating the global redistribution of people and property" and published in the journal One Earth, comes from an international team of climate and social scientists. 

    Millions of people are projected to be displaced by sea-level rise in the next decades, and 2 billion could be exposed to extreme heat beyond their experience by the end of the century.

    Ignoring or downplaying the inevitable global redistribution of people would lead to geo-political instability, and a polarized and fractured world.

    "Instead, the international community must come together to rethink mobility and cultural integration to ensure a benign transition to this new world."

    So far, most migration with significant climate dimensions has happened within countries, with people leaving areas affected by long-term decline in agricultural productivity or escaping conditions such as coastal erosion or extreme events.

    While some large nations have different climate zones that can accommodate this, small countries do not.

    The paper also warns that a "skewed distribution of wealth and associated power" makes it difficult for people to move, both within and between states.

    Global warming exacerbates existing inequalities, making habitability a major political challenge of this century.

    "Concrete cooperation is now needed to match migrant flows with demand for labor, to the benefit of the Global South and the developed world alike.

    The paper says major reform of the food system, supported by movement of workers, could increase production while conserving nature.

    Migration can therefore be a win–win for people and the climate, but leaders must make a positive case for economic benefits and effective integration. "Playing up the social costs of migration appeals to national identity motivations, but fails to overcome problems from aging populations.

    Instead, leaders should focus on the economic and social benefits of new populations and effective integration, which benefits newcomers and original inhabitants alike.

    "Every corner of the world needs to anticipate the coming climate crisis and promote the safe and beneficial movement of people as conditions change.

    It is the question of survival and you can't stop people from moving when their very existence is under threat. 

    Marten Scheffer et al, Anticipating the global redistribution of people and property, One Earth (2024). DOI: 10.1016/j.oneear.2024.06.008

    You 

  • Dr. Krishna Kumari Challa

    Why the solar corona is so much hotter than sun's surface

    In a new study published in The Astrophysical Journal,  researchers explore critical aspects of a phenomenon called kinetic Alfvén waves (KAWs) to provide fresh insights into an age-old heliophysics mystery.

    They examined the potentially pivotal role of KAWs in heating the solar corona, moving science one step closer to solving the puzzle of why the corona is many times hotter than the surface of the sun itself.

    For decades, Alfvén waves have been proven to be the best candidates for transporting energy from one place to another. 

    This paper utilizes a novel approach to model energetic particles in space plasmas, as observed by satellites like Viking and Freja, to answer how the electromagnetic energy of the waves, interacting with particles, transforms into heat during the damping process as the waves move through space.

    The corona, or solar atmosphere, is an enigmatic region surrounding our home star that extends far beyond the visible disk of the sun, stretching some 8 million kilometers above the sun's surface. Yet, the corona is also characterized by extraordinarily high temperatures, a mystery that has captivated astrophysicists for nearly seventy years.

    This new work  offers important insights into the critical problem of how energy in a magnetic field is transformed to heat a plasma comprising charged particles like protons and electrons.

    Kinetic Alfvén waves—abundant throughout the plasma universe—are oscillations of the ions and magnetic field as they move through the solar plasma. The waves are formed by motions in the photosphere, the sun's outer shell that radiates visible light.

    Part 1

  • Dr. Krishna Kumari Challa

    The researchers focused on the heating and energy exchange facilitated by KAWs. The reason for the great interest in these waves lies in their ability to transport energy. Observational data from numerous spacecraft and theoretical investigations have consistently demonstrated that KAWs dissipate and contribute to solar coronal heating during their propagation in space.
    Because of these unique properties, the waves provide a critical mechanism for transferring energy, important to understanding the energy exchange between electromagnetic fields and plasma particles.
    KAWs operate on small kinetic scales and are capable of supporting parallel electric and magnetic field fluctuations, enabling an energy transfer between the wave field and plasma particles through a phenomenon called Landau interactions.
    The present work utilized and explores the Landau damping mechanism, which occurs when particles moving parallel to a wave have velocities comparable to the wave's phase velocity.
    Landau damping is an exponential decrease as a function of time of particular waves in plasma. "When particles interact with the wave, they receive/lose energy—a term called 'resonant condition.
    Part 2

  • Dr. Krishna Kumari Challa

    This can result in the wave either delivering its energy to the particles or gaining energy from them, causing the particles to either damp or grow.
    This new research work finds that KAWs rapidly dissipate, completely transferring their energy to plasma particles in the form of heating. This energy transfer accelerates the particles over longer spatial distances, significantly impacting the dynamics of the plasma.
    The analytical insights gleaned from this study will find practical application in understanding phenomena within the solar atmosphere, particularly shedding light on the significant role played by non-thermal particles in the heating processes.

     Syed Ayaz et al, Solar Coronal Heating by Kinetic Alfvén Waves, The Astrophysical Journal (2024). DOI: 10.3847/1538-4357/ad5bdc

    Part 3

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  • Dr. Krishna Kumari Challa

     Chimpanzees  are capable of speech

    Axel G. Ekström et al, Chimpanzee utterances refute purported missing links for novel vocalizations and syllabic speech, Scientific Reports (2024). DOI: 10.1038/s41598-024-67005-w

  • Dr. Krishna Kumari Challa

    How to cope with increasingly hot summers

    • Use an electric fan, a particularly effective method in humid climates like Quebec's. But remember: using a fan can be counter-productive in very low humidity or above 40° C temperatures.
    • Sponge yourself regularly with cool water.
    • Soak your feet in cold water.
    • Stay socially connected (especially important for seniors and the socially isolated).
    • Set your air conditioner to 25° C instead of 20° C to build up your tolerance to higher temperatures (and reduce energy consumption).

    More information: Hadiatou Barry et al, The Effect of Heat Exposure on Myocardial Blood Flow and Cardiovascular Function, Annals of Internal Medicine (2024). DOI: 10.7326/M24-3504

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  • Dr. Krishna Kumari Challa

    Confirmed link between maternal asthma and child allergies

    For the first time, researchers  have confirmed maternal asthma increases risks of child allergies.

    In a systematic review of more than 20,000 sources, the researchers discovered children whose mothers have asthma are 76% more likely to have the condition themselves.

    The review is the first time anyone has brought together the data on how severity and control of asthma during pregnancy affects allergy and asthma outcomes in children. It also found that better asthma control during pregnancy reduces the risk in children.

    They found found maternal asthma is associated with an increased risk of wheeze (59%), food allergy (32%), eczema (17%) and hay fever (18%),

    The findings are published in the BJOG: An International Journal of Obstetrics & Gynaecology.

    Associations between maternal asthma and risks of progeny asthma were similar when the exposure was maternal asthma during the index pregnancy or as a history of asthma, consistent with the chronic nature of asthma.

    Uncontrolled and more severe maternal asthma during the index pregnancy were also associated with increased risk of progeny asthma.

    Andrea J. Roff et al, Maternal asthma during pregnancy and risks of allergy and asthma in progeny: A systematic review and meta‐analysis, BJOG: An International Journal of Obstetrics & Gynaecology (2024). DOI: 10.1111/1471-0528.17900

  • Dr. Krishna Kumari Challa

    Blocking One Protein Extends Lifespan in Mice by Up to 25%

    A protein called interleukin 11 (IL-11) appears to play a crucial role in aging, with scientists extending the lifespans of mice by up to 25 percent simply by blocking the molecule's effects.

    Researchers  used genetic engineering to turn off IL-11 production in a sample of mice, while injecting other mice with an anti-IL-11 drug.

    Deaths from cancer and tumorous growths were reduced in both groups, while health conditions related to the effects of aging – including chronic inflammation and poor metabolism – were also less common.

    The treated mice had fewer cancers, and were free from the usual signs of aging and frailty, but researchers also saw reduced muscle wasting and improvement in muscle strength. In other words, the old mice receiving anti-IL-11 were healthier.

    Interleukin 11 has been of interest to scientists studying the aging process for several years. We know that it builds up in the body as we get older, and it's linked to increasing levels of inflammation, scar tissue, and overall frailty.

    https://www.nature.com/articles/s41586-024-07701-9

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

    First, keep your head back with your ears submerged to keep your airways open. Resist the urge to panic, try to relax and breathe normally. Gently move your hands paddling them as this will aid in keeping afloat. Don't fret if your legs sink, everyone's buoyancy is different. Finally, spread your arms and legs as this really helps maintain your stability in the water.

  • Dr. Krishna Kumari Challa

    More women are ending pregnancies on their own, a new study suggests. Some resort to unsafe methods

    A growing number of women said they've tried to end their pregnancies on their own by doing things like taking herbs, drinking alcohol or even hitting themselves in the belly, a new study suggests.

    Researchers surveyed reproductive-age women in the U.S. before and after the Supreme Court overturned Roe v. Wade in June 2022. The proportion who reported trying to end pregnancies by themselves rose from 2.4% to 3.3%.

    A lot of people are taking things into their own hands.

    Study authors acknowledged that the increase is small. But the data suggests that it could number in the hundreds of thousands of women.

    Researchers surveyed about 7,000 women six months before the Supreme Court decision, and then another group of 7,100 a year after the decision. They asked whether participants had ever taken or done something on their own to end a pregnancy. Those who said yes were asked follow-up questions about their experiences.

    The data show that making abortion more difficult to access is not going to mean that people want or need an abortion less frequently.

    Women gave various reasons for handling their own abortions, such as wanting an extra measure of privacy, being concerned about the cost of clinic procedures and preferring to try to end their pregnancies by themselves first.

    They reported using a range of methods. Some took medications—including emergency contraception and the abortion pills misoprostol and mifepristone obtained outside the medical system and without a prescription. Others drank alcohol or used drugs. Some resorted to potentially harmful physical methods such as hitting themselves in the abdomen, lifting heavy things or inserting objects into their bodies.

    Some respondents said they suffered complications like bleeding and pain and had to seek medical care afterward. Some said they later had an abortion at a clinic. Some said their pregnancies ended after their attempts or from a later miscarriage, while others said they wound up continuing their pregnancies when the method didn't work.

    Respondents may be under-reporting their abortions because researchers are asking them about "a sensitive and potentially criminalized behaviour."

     The study's findings confirm the statement : If you make it hard to get (an abortion) in a formal setting, people will just do it informally.

    Lauren Ralph et al, Self-Managed Abortion Attempts Before vs After Changes in Federal Abortion Protections in the US, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.24310

  • Dr. Krishna Kumari Challa

    Study finds working from home stifles innovation

    Remote and hybrid working may be great for employees' work-life balance, but it may be stifling innovation, according to new research.

    The study found that staff who worked in a hybrid model were less likely to come up with innovative ideas than colleagues who always worked in the office. And staff working from home tended to produce lower quality innovative ideas than those who always worked in the office. 

    Innovation in the workplace can occur through random, spontaneous 'watercooler' conversations between employees. However, these 'productive accidents' are less likely to occur when employees work from home. This  research work has found that innovation is suffering as a result.

    Michael Gibbs et al, Employee innovation during office work, work from home and hybrid work, Scientific Reports (2024). DOI: 10.1038/s41598-024-67122-6

  • Dr. Krishna Kumari Challa

    Scientists 'Mind Controlled' Mice Remotely 

    At the mere flick of a magnetic field, mice engineered with nanoparticle-activated 'switches' inside their brains were driven to feed, socialize, and act like clucky new mothers in an experiment designed to test an innovative research tool.

    While 'mind control' animal experiments are far from new, they have generally relied on cumbersome electrodes tethering the subject to an external system, which not only requires invasive surgery but also sets limits on how freely the test subject can move about.
    In what is claimed to be a breakthrough in neurology, researchershave developed a method for targeting pathways in the brain using a combination of genetics, nanoparticles, and magnetic fields.

    They call the technology Nano-MIND, an acronym for Magnetogenetic Interface for NeuroDynamics. And while mind-control is a coarse but relatively accurate way of describing it, the system in its current form is intended to provide researchers with a means of remotely activating neural circuits for a range of research applications.

    This is the world's first technology to freely control specific brain regions using magnetic fields. Magnetic stimulation is an emerging field of research in neurology, where washing the brain with pulses of electromagnetism broadly massages whole regions into subtly changing their behavior. 

    To target specific circuits, the researchers took a leaf out of another field of research called optogenetics, which genetically engineers mechanisms into cells that can be readily activated by a light source. In this case, the team integrated ion channels into targeted populations of brain cells in mice. Instead of delivering light through a localized fiber, as in optogenetics, the ion channels could be switched on magnetically with a twist of a tiny actuator. All that's required is a surrounding field that's strong enough to pull at the nanoparticle.

    similar nanotechnology may even treat poor mental health in humans or play a significant role in therapies for debilitating neurological conditions, thereby returning complete control of a person's mind back to the individual.

    https://www.nature.com/articles/s41565-024-01694-2

  • Dr. Krishna Kumari Challa

    43% of cocoa products exceed lead safety levels, study finds

    When our friends, relatives and colleagues come from the US they bring lots of chocolates  and we consume them very fondly. But this new information is alarming ....

    A new study  found a disquieting percentage of cocoa products in the U.S. contain heavy metals that exceed guidelines, including higher concentrations in organic products.

    The study, "A Multi-Year Heavy Metal Analysis of 72 Dark Chocolate and Cocoa Pr... was published on July 31, 2024 in Frontiers in Nutrition.

    Researchers analyzed 72 consumer cocoa products, including dark chocolate, every other year over an eight year period for contamination with lead, cadmium, and arsenic, heavy metals that pose a significant health hazard in sufficient amounts.

    We all love chocolate but it's important to indulge with moderation, as with other foods that contain heavy metals, including large fish like tuna and unwashed brown rice. While it's not practical to avoid heavy metals in your food entirely, you must be cautious of what you are eating and how much.

    The researchers used a threshold of maximum allowable dose levels to assess the extent of heavy metal contamination in an array of chocolate products, found on grocery store shelves.

    Key findings:

    43% of the products studied exceeded the maximum allowable dose level for lead. 35% of the products studied exceeded the maximum allowable dose level for cadmium.

    None of the products exceeded the maximum allowable dose level for arsenic. Surprisingly, organic labeled products showed higher levels of both lead and cadmium compared to non-organic products.

    For the average consumer, consuming a single serving of these cocoa products may not pose significant health risks based on the median concentrations found. However, consuming multiple servings or combining consumption with other sources of heavy metals could lead to exposures that exceed the maximum allowable dose level.

    Foods with high lead levels may include animal foods that can bioaccumulate heavy metals (shellfish, organ meats) and foods or herbal supplements grown in contaminated soil and/or imported from countries with less regulation.  For cadmium, the main concerns are the same with the addition of some seaweeds.

    Consumers should be aware of potential cumulative exposure risks, particularly with cocoa products labeled organic, as they may have higher heavy metal concentrations. A serving size of dark chocolate is typically one ounce and has been generally suggested to have health benefits including cardiovascular health, cognitive performance, and chronic inflammation.

     Study Finds Many Cocoa Products Contaminated by Heavy Metals, Frontiers in Nutrition (2024). DOI: 10.3389/fnut.2024.1366231 , www.frontiersin.org/journals/n … 024.1366231/abstract

  • Dr. Krishna Kumari Challa

    Incidence of heart attacks and strokes was lower after COVID-19 vaccination, finds study of 46 million adults

    A new study, published recently in Nature Communications and involving nearly the whole adult population of England, has found that the incidence of heart attacks and strokes was lower after COVID-19 vaccination than before or without vaccination.

    Researchers analyzed de-identified health records from 46 million adults in England between 8 December 2020 and 23 January 2022. Data scientists compared the incidence of cardiovascular diseases after vaccination with the incidence before or without vaccination, during the first two years of the vaccination program.

    The study showed that the incidence of arterial thromboses, such as heart attacks and strokes, was up to 10% lower in the 13 to 24 weeks after the first dose of a COVID-19 vaccine. Following a second dose, the incidence was up to 27% lower after receiving the AstraZeneca vaccine and up to 20% lower after the Pfizer/Biotech vaccine. The incidence of common venous thrombotic events—mainly pulmonary embolism and lower limb deep venous thrombosis—followed a similar pattern.

    This research further supports the large body of evidence on the effectiveness of the COVID-19 vaccination program, which has been shown to provide protection against severe COVID-19 and saved millions of lives worldwide. It did not identify new adverse cardiovascular conditions associated with COVID-19 vaccination and offers further reassurance that the benefits of vaccination outweigh the risks.

    The incidence of cardiovascular disease is higher after COVID-19, especially in severe cases. This may explain why the incidence of heart attacks and strokes is lower in vaccinated people compared with unvaccinated people.

    Cohort study of cardiovascular safety of different COVID-19 vaccination doses among 46 million adults in England, Nature Communications (2024). DOI: 10.1038/s41467-024-49634-x

  • Dr. Krishna Kumari Challa

    AI predicts male infertility risk with blood test, no semen needed

    According to a World Health Organization (WHO) study (2017), about half of all infertility is due to men. Semen analysis is considered essential for diagnosis of male infertility, but is not readily available at medical institutions other than those specializing in infertility treatment, and there is a high threshold for receiving it.

    In a new study, researchers developed an AI model that can predict the risk of male infertility without the need for semen analysis by only measuring hormone levels in a blood test. AI creation software that requires no programming was used for the model, and the study was reported in Scientific Reports.

    The AI prediction model was based on data from 3,662 patients and had an accuracy rate of approximately 74%. In particular, it was 100% correct in predicting non-obstructive azoospermia, the most severe form of male infertility.

    The current study collected clinical data from 3,662 men who underwent semen and hormone testing for male infertility between 2011 and 2020. Semen volume, sperm concentration, and sperm motility were measured in the semen tests, and LH, FSH, PRL, testosterone, and E2 were measured in the hormone tests. T/E2 was also added. Total motile sperm count (semen volume X sperm concentration X sperm motility rate) was calculated from the semen test results.

    Based on the reference values for semen testing in the WHO laboratory manual for the examination and processing of human semen, 6th edition (2021), a total motile sperm count of 9.408 X 106 (1.4 mL X 16 X 106/mL X 42%) was defined as the lower limit of normal, assigning a value of "0" if the total motility sperm count for an individual patient was above 9.408 X 106 and a value of "1" when it was below. The accuracy of the AI model was approximately 74%.

    A New Model for Determining Risk of Male Infertility from Serum Hormone Levels, without Semen Analysis, Scientific Reports (2024).

    Next, the AI model was validated using data from 2021 and 2022 for which both semen and hormone tests were available. Using the data of 188 patients in 2021, the accuracy was about 58%, while accuracy using the data for 166 patients in 2022 was about 68%. However, non-obstructive azoospermia could be predicted with a 100% accuracy rate in both 2021 and 2022.

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

    Who needs males? Female sharks make babies alone

     Researchers have noted the first case of "virgin birth", or reproduction without fertilization, in an endangered shark species, a scientific journal reported this week.

    The findings published in Scientific Reports concern the first case of the phenomenon in the common smooth-hound shark, Mustelus mustelus, a species threatened by illegal fishing that inhabits the Mediterranean and other warm waters.

    Researchers found that two female M. mustelus sharks under observation in captivity had exhibited parthenogenesis—in which a female can reproduce asexually without the need of sperm to fertilize the egg—each year since 2020.

    The two 18-year-old sharks have been at the Cala Gonone Aquarium in Sardinia since 2010.

    Remarkably, this finding reveals that parthenogenesis can occur annually in these sharks, alternating between two females, and conclusively excludes long-term sperm storage as a cause.

    Cycling parthenogenesis, in which progeny can be born either from fertilized eggs or asexually with unfertilized eggs, occurs in over 15,000 species, yet is not fully understood.

    Parthenogenesis,  is more common in invertebrates than vertebrates. Reptiles and some sharks, rays and skates are able to "modify their adaptive strategy according to the surrounding circumstances".

    Although the mechanisms driving parthenogenesis remain unclear, it is suggested that male population reduction could be a pivotal factor.

    Giuseppe Esposito et al, First report of recurrent parthenogenesis as an adaptive reproductive strategy in the endangered common smooth-hound shark Mustelus mustelus, Scientific Reports (2024). DOI: 10.1038/s41598-024-67804-1

  • Dr. Krishna Kumari Challa

    Why men and women feel touch differently

    Why women generally seem to have a more acute sense of touch than men?

     Women are better than men at touch discrimination—although not because they have smaller fingers, but because in general they have softer fingers. 

    But demonstrating the "why" behind the gender difference, first published in November 2023 in the Journal of Physiology, continues to be a cited topic of interest. The insight could be useful as engineers develop softer sensor materials for wearable technology, improve prosthetics with a sense of touch, or design better interfaces for surgical robots.

    The experimental design combined novel 3D imaging and biomechanical observations of skin and how it deforms when pressed, statistical analysis and machine learning, and experiments to test how the participants used touch to perceive objects.
    They found that softer skin resulted in greater rates of change in surface contact with objects, which correlated with a greater ability to distinguish small changes in the objects' stiffness.

    "The mechanism seems to be that attributes of surface contact control the recruitment of sensory nerve fibers in the skin".

    For those who'd like to improve their touch perception, the researchers said, apply hyaluronic acid, an effective skin moisturizer and softener.

    Bingxu Li et al, An individual's skin stiffness predicts their tactile discrimination of compliance, The Journal of Physiology (2023). DOI: 10.1113/JP285271

  • Dr. Krishna Kumari Challa

    Engineered microbes found to repel mosquitoes

    Genetically-engineered human skin bacteria can make mice less attractive to mosquitoes for 11 days. Mosquitoes transmit a host of deadly diseases, including malaria, West Nile, dengue, yellow fever, and Zika. Female mosquitoes on the hunt for a blood meal tune into scents released by skin microbes that live on their targets.

    Researchers engineered versions of the common human  skin commensals Staphylococcus epidermidis and Corynebacterium amycolatum to produce much less of a form of lactic acid known to attract mosquitoes. The work is published in the journal PNAS Nexus.

    The authors tested the microbes alone and found the engineered version of S. epidermidis attracted about half as many Aedes aegypti and Anopheles gambiae mosquitoes and about 22% fewer Culex quinquefasciatus as the wildtype versions of the microbes.

    The authors also tried the engineered microbes on mice. Painting the mice with wildtype S. epidermidis attracted mosquitos. However, painting the mice with engineered S. epidermidis reduced mosquito attraction by up to 64.4%, compared with wildtype, starting three days after the microbe was applied.

    The effect lasted for 11 days. Trials with engineered C. amycolatum had similar results. In addition, a smaller proportion of mosquitoes that landed on mice painted with engineered microbes bit the mice. According to the authors, the results suggest the feasibility of creating a living and long-lasting engineered microbiome-based mosquito repellent.

     Feng Liu et al, Engineered skin microbiome reduces mosquito attraction to mice, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae267

  • Dr. Krishna Kumari Challa

    Study uncovers unique brain plasticity in people born blind

    A study by neuroscientists reveals that the part of the brain that receives and processes visual information in sighted people develops a unique connectivity pattern in people born blind. They say this pattern in the primary visual cortex is unique to each person—akin to a fingerprint.

    The findings, described July 30, 2024, in PNAS, have profound implications for understanding brain development and could help launch personalized rehabilitation and sight restoration strategies.

    For decades, scientists have known that the visual cortex in people born blind responds to a myriad of stimuli, including touch, smell, sound localization, memory recall and response to language. However, the lack of a common thread linking the tasks that activate primary areas in the visual cortex has perplexed researchers.

    The new study offers a compelling explanation: differences in how each individual's brain organizes itself.

    We don't see this level of variation in the visual cortex connectivity among individuals who can see—the connectivity of the visual cortex is usually fairly consistent, say the researchers.

    The connectivity pattern in people born blind is more different across people, like an individual fingerprint, and is stable over time—so much so that the individual person can be identified from the connectivity pattern.

    Lénia Amaral et al, Longitudinal stability of individual brain plasticity patterns in blindness, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2320251121

  • Dr. Krishna Kumari Challa

    Study links TB strain infectivity to shared geographic background

    For some forms of tuberculosis, the chances that an exposed person will become infected depend on whether the individual and the bacteria share a hometown, according to a new study comparing how different strains move through mixed populations in cosmopolitan cities.

    Results of the research, led by Harvard Medical School scientists and published in Nature Microbiology, provide the first hard evidence of long-standing observations that have led scientists to suspect that pathogen, place, and human host collide in a distinctive interplay that influences infection risk and fuels differences in susceptibility to infection.

    The study strengthens the case for a long-standing hypothesis in the field that specific bacteria and their human hosts likely co-evolved over hundreds or thousands of years, the researchers said.

    The findings may also help inform new prevention and treatment approaches for tuberculosis, a wily pathogen that sickens more than 10 million people and causes more than a million deaths worldwide each year, according to the World Health Organization.

    In the current analysis, believed to be the first controlled comparison of TB strains' infectivity in populations of mixed geographic origins, the researchers custom built a study cohort by combining case files from patients with TB in New York City, Amsterdam, and Hamburg. Doing so gave them enough data to power their models.

    The analysis showed that close household contacts of people diagnosed with a strain of TB from a geographically restricted lineage had a 14% lower rate of infection and a 45% lower rate of developing active TB disease compared with those exposed to a strain belonging to a widespread lineage.

    The study also showed that strains with narrow geographic ranges are much more likely to infect people with roots in the bacteria's native geographic region than people from outside the region.

    The researchers found that the odds of infection dropped by 38% when a contact is exposed to a restricted pathogen from a geographic region that doesn't match the person's background, compared with when a person is exposed to a geographically restricted microbe from a region that does match their home country. This was true for people who had lived in the region themselves and for people whose two parents could each trace their heritage to the region.

    This pathogen-host affinity points to a shared evolution between humans and microbes with certain biological features rendering both more compatible and fueling the risk for infection, the researchers said.

    Part 1

  • Dr. Krishna Kumari Challa

    the new study showed that for geographically restricted strains, whether a person has ancestors who lived where the strain is common was an even bigger predictor of infection risk than bacterial load in the sputum. In the cases analyzed in the study, this risk of common ancestry even outweighed the risk stemming from having diabetes and other chronic diseases previously shown to render people more susceptible to infection.

    The findings add to a growing body of evidence of the importance of paying attention to the wide variation between different lineages of tuberculosis and to the details of how different lineages of tuberculosis interact with different host populations.

    Previous studies have shown that some genetic groups of TB are more prone to developing drug resistance and that TB vaccines appear to work better in some places than others. There is also evidence that some treatment regimens might be better suited to some strains of TB than others.

    "These findings emphasize how important it is to understand what makes different strains of TB behave so differently from one another, and why some strains have such a close affinity for specific, related groups of people.

    In addition to the analysis of clinical, genomic, and public health data, the researchers also tested the ability of different strains of TB to infect human macrophages, a type of immune cell that TB hijacks to cause infection and disease. The researchers grew cells from donors from different regions. Once again, cell lines from people with ancestry that matched the native habitat of a restricted strain of tuberculosis bacteria were more susceptible to the germs than cells from people from outside the area, mirroring the results of their epidemiologic study.

    Differential rates of Mycobacterium tuberculosis transmission associate with host–pathogen sympatry, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01758-y

    Part 2

  • Dr. Krishna Kumari Challa

    Warming breaks down symbiosis

    Hotter conditions prevent two tiny organisms working together for mutual benefit, new research shows.

    Scientists studied a single-celled organism (Paramecium bursaria) which can absorb and host algae (Chlorella spp). This pairing is common in freshwater worldwide, and their symbiotic relationship provides benefits including trading of nutrients and protection for the algae.

    But when scientists made the water 5°C warmer, the partnership stopped working—and the results suggest the algae may even become parasitic.

    The breakdown of such relationships could have a major impact on ecosystems.

    The paper, published in the journal Aquatic Biology, is titled "One year of warming leads to the total loss of productivity in a widespread photosymbiosis."

    This kind of relationship—called photosymbiosis—is an important part of freshwater and ocean ecosystems.

    To illustrate their importance, these relationships provide around half of all marine photosynthesis.

    A well-known example is found in coral reefs—where the reef-building corals host resident photosynthetic partners. In recent years, we have seen many high-profile 'bleaching' events—when corals expel these partners, often due to high temperatures, leaving them at risk of stress and mortality.

    B Makin et al, One year of warming leads to the total loss of productivity in a widespread photosymbiosis, Aquatic Biology (2024). DOI: 10.3354/ab00769

  • Dr. Krishna Kumari Challa

    Study finds regular aspirin use associated with greatest reduction in colorectal cancer among those most at risk

    Regular aspirin may help lower risk of colorectal cancer in people with greater lifestyle-related risk factors for the disease, according to a study by researchers. 

     The study, published in JAMA Oncology, could encourage a more nuanced approach to preventive aspirin use.

    The U.S. Preventive Services Task Force previously recommended daily low-dose aspirin to prevent cardiovascular events and colorectal cancer in all adults ages 50 to 59 (the highest risk age group for colorectal cancer). In 2016, they withdrew the recommendation in part due to concerns about aspirin increasing the risk of gastrointestinal bleeding.

    For the study, researchers analyzed the health data from 107,655 participants from the Nurses' Health Study and Health Professionals Follow-Up Study. They compared the colorectal cancer rates in those who took aspirin regularly with those who did not take aspirin regularly. Regular aspirin use was defined as either two or more standard dose (325 mg) tablets per week or daily low-dose (81 mg) aspirin.

    Study participants were followed starting from an average age of 49.4 years. Those who regularly took aspirin had a colorectal cancer 10-year cumulative incidence of 1.98%, compared to 2.95% among those who did not take aspirin.

    The benefit of aspirin was largest among those with the unhealthiest lifestyles. Those with the lowest healthy lifestyle scores (unhealthiest) had a 3.4% chance of getting colorectal cancer if they did not take regular aspirin and a 2.12% chance of getting colorectal cancer if they took aspirin regularly.

    By contrast, in those with the highest healthy lifestyle scores (healthiest), the colorectal cancer rates were 1.5% in regular aspirin-taking group and 1.6% in the non-regular aspirin group. This means that in the least healthy group, treating 78 patients with aspirin would prevent one case of colorectal cancer over a 10-year period, while it would take treating 909 patients to prevent one case for the healthiest group.

    Lifestyle scores were calculated based on  body mass index, frequency of cigarette and alcohol use, physical activity, and adherence to a high-quality diet.

    These results show that aspirin can proportionally lower the markedly elevated risk in those with multiple risk factors for colorectal cancer.

    In contrast, those with a healthier lifestyle have a lower baseline risk of colorectal cancer, and, therefore, their benefit from aspirin was still evident, albeit less pronounced.

    Part1

  • Dr. Krishna Kumari Challa

    One outcome of the study could be that "health care providers might more strongly consider recommending aspirin to patients who have less healthy lifestyles.
    Previous studies have found evidence to suggest aspirin can reduce the production of pro-inflammatory proteins, known as prostaglandins, that can promote the development of cancer. Aspirin may also block signaling pathways that cause cells to grow out of control, influence the immune response against cancer cells, and block the development of blood vessels that supply nutrients to cancer cells.

    Aspirin likely prevents colorectal cancer through multiple mechanisms.
    The study did not assess potential side effects of daily aspirin use, such as bleeding. In addition, while the study tried to control for a wide range of risk factors for colorectal cancer, in comparing non-aspirin and aspirin-taking groups with the same level of risk factors, because this was an observational study, it is possible there may have been additional factors that influenced the findings.

     Aspirin Use and Incidence of Colorectal Cancer According to Lifestyle Risk, JAMA Oncology (2024). DOI: 10.1001/jamaoncol.2024.2503

    Part 2

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  • Dr. Krishna Kumari Challa

    Paper cut physics: the physics behind why some paper is more prone to cut fingers

    We all know what it’s like to pick up a sheet of paper, only to get a painful paper cut. The injury is usually small and shallow, but it can really hurt!
    Your body has hundreds of nerves. These nerves are spread throughout your body, from head to toe.
    In your hands and fingers, though, the nerve endings are densely packed together. So, they’re more sensitive than other areas, like your back or arm.
    This explains why paper cuts hurt so much. They commonly affect the hands and fingers, which have a higher density of nerve endings.
    But what about all the blood? Well, the capillaries in your hands and fingers are closely packed together. This means paper cuts can cause a lot of bleeding because of how concentrated blood can be in your hands.

    In experiments with a gelatin replica of human tissue, researchers found that a thin sheet of paper tended to buckle before it could cut. Thick paper typically indented the material but didn’t pierce it: Like a dull knife blade, it didn’t concentrate force into a small enough area. A thickness of around 65 micrometers was a paper cut sweet spot — or sore spot — physicist Kaare Jensen and colleagues report in a paper to appear in Physical Review E.

    That makes dot matrix printer paper the most treacherous, the researchers say. (That paper is seldom used today ). Paper from various magazines was a close second in the scientists’ tests. 

    The angle of slicing also played a role. Paper pressed straight down into the gelatin was less likely to cut than paper that cleaved across and down.

    S.F. Arnbjerg-Nielsen, M.D. Biviano and K.H. Jensen. Competition between slicing and buckling underlies the erratic natu...Physical Review E, in press, 2024.

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

    Almost Half of Dementia Cases Avoidable by Addressing 14 Risk Factors, Major Study Finds

    Millions of cases of dementia could be prevented or delayed by reducing a range of risk factors according to a major new study, though outside experts warn that such measures can only go so far.

    The debilitating condition, which progressively robs people of their memories, cognitive abilities, language and independence, currently affects more than 55 million people across the world. Dementia is caused by a range of diseases, the most common of which is Alzheimer's.

    A huge review of the available evidence published in The Lancet journal on Wednesday said that the "potential for prevention is high" in the fight against dementia.

    The study follows a previous report in 2020 that also emphasised the importance of prevention.

    At the time, the international team of researchers estimated that 40 percent of dementia cases were linked to 12 risk factors.

    The factors included people having a lower level of education, hearing problems, high blood pressure, smoking, obesity,  depression physical inactivity,  diabetes, excessive drinking, traumatic brain injury, air pollution and social isolation.

    The latest update adds two more risk factors: vision loss and high cholesterol.

    "Nearly half of dementias could theoretically be prevented by eliminating these 14 risk factors," the study said.

  • Dr. Krishna Kumari Challa

    Added Sugar in Your Diet May Speed Up Your Body's Biological Aging

    Eating large amounts of food with added sugar could have a hyperactive effect on the body's ticking biological clock, even when the rest of a person's diet remains otherwise healthy.

    A new study among 342 Black and White middle-aged women (please note that the sample size is very low) has found those who eat high quantities of added sugar have 'older-looking' cells.

    The findings could help explain why some people seem to age faster or slower than others who have lived the same number of years. Sugar intake could be an important, overlooked factor.

    Along with the occasional mutation, our DNA can accumulate less permanent edits over time. These so-called epigenetic changes often act like chemical padlocks, deactivating genes and altering how the body's genetic code is expressed for a time.
    A collection of transient edits is referred to as an epigenetic clock, and can be a useful way to guess at a person's true biological age. Epigenetic changes can be read by scientists to better understand how old a cell is and what damages or stresses it has experienced.

    Diet, lifestyle, genetics, and disease are all known to affect how quickly a person's epigenetic clock ticks, but this is one of the first studies to examine how sugar specifically plays a role. It also includes a diverse cohort.

    The findings suggest that added sugar can alter epigenetic switches related to aging more quickly than healthier foods can turn them off, regardless of whether healthy nutrients are also present.

    Part 1