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

    World's richest 1% emit as much carbon as bottom two-thirds: report

    The richest one percent of the global population are responsible for the same amount of carbon emissions as the world's poorest two-thirds, or five billion people, according to an analysis published Sunday by the nonprofit Oxfam International.

    While fighting the climate crisis is a shared challenge, not everyone is equally responsible and government policies must be tailored accordingly, according to the report.

    It says, the richer you are, the easier it is to cut both your personal and your investment emissions. You don't need that third car, or that fourth holiday, or you don't need to be invested in the cement industry." 

    Climate Equality: A Planet for the 99%", was based on research compiled by the Stockholm Environment Institute (SEI) and it examined the consumption emissions associated with different income groups up to the year 2019.
    Among the key findings of this study are that the richest one percent globally—77 million people—were responsible for 16 percent of global emissions related to their consumption.

    That is the same share as the bottom 66 percent of the global population by income, or 5.11 billion people.
    Source: 2023 AFP
  • Dr. Krishna Kumari Challa

    What is a sonar pulse and how can it injure humans under water?
    Light doesn't travel well underwater—even in clear waters, you can see perhaps some tens of meters. Sound, however, travels very well and far underwater. This is because water is much denser than air, and so can respond faster and better to acoustic pressure waves—sound waves.

    Because of these properties, ships use sonar to navigate through the ocean and to "see" underwater. The word "sonar" stands for sound navigation and ranging.

    Sonar equipment sends out short acoustic (sound) pulses or pings and then analyzes the echoes. Depending on the timing, amplitude, phase, and direction of the echoes the equipment receives, you can tell what's underwater—the seafloor, canyon walls, coral, fishes, and of course, ships and submarines.

    Most vessels—from small, private boats to large commercial tankers—use sonar. However, compared to your off-the-shelf sonar used for finding fish, navy sonars are stronger.
    The effects of sonar on divers
    We don't hear well underwater—no surprise since we've evolved to live on land. Having said that, you would hear a sonar sound underwater (a mid-to-high pitch noise) and would know you've been exposed.
    When it comes to naval sonars, human divers have rated the sound as "unpleasant to severe" at levels of roughly 150dB re 1 µPa (decibel relative to a reference pressure of one micro pascal, the standard reference for underwater sound). This would be, perhaps, very roughly 10km away from a military sonar. Note that we can't compare sound exposure under water to what we'd receive through the air because there are too many physical differences between the two.

    Human tolerance limits are roughly 180dB re one µPa, which would be around 500m from military sonar. At such levels, humans might experience dizziness, disorientation, temporary memory and concentration impacts, or temporary hearing loss.
    At higher received levels, closer ranges, or longer exposures, you might see more severe physiological or health impacts. In extreme cases, in particular, for impulsive, sudden sound (which sonar is not), sound can cause damage to tissues and organs.
    What does sonar do to marine animals?
    Some of the information on what noise might do to humans underwater comes from studies and observations of animals.

    While they typically don't have outer ears (except for sea lions), marine mammals have inner ears that function similarly to ours. They can receive hearing damage from noise, just like we do. This might be temporary, like the ringing ears or reduced sensitivity you might experience after a loud concert, or it can be permanent.

    Marine mammals living in a dark ocean rely on sound and hearing to a greater extent than your average human. They use sound to navigate, hunt, communicate with each other and to find mates. Toothed whales and dolphins have evolved a biological echo sounder or biosonar, which sends out series of clicks and listens for echoes. So, interfering with their sounds or impacting their hearing can disrupt critical behaviors.

    Finally, sound may also impact non-mammalian fauna, such as fishes, which rely on acoustics rather than vision for many of their life functions.

    https://theconversation.com/what-is-a-sonar-pulse-and-how-can-it-in...

  • Dr. Krishna Kumari Challa

    AWEsome Waves in Earth’s Airglow

  • Dr. Krishna Kumari Challa

    A wearable robot that assists people with walking

    In recent years, roboticists have introduced increasingly advanced systems, which could open exciting new possibilities for surgery, rehabilitation, and health care assistance. These robotic systems are already helping to improve the quality of life of many people with disabilities, as well as patients who suffered physical

    trauma or underwent medical procedures.

    Researchers recently introduced a new wearable robot designed to specifically assist humans who have difficulties walking due to aging, muscle weakness, surgeries or specific medical conditions. This robot, presented in a paper published in Science Robotics, was found to improve balance, while also reducing the energy spent while walking (the so-called metabolic cost). 

    In contrast with other robotic systems for hip abduction assistance proposed in the past, the robot now created  focuses on the frontal plane. This is the frontal part of the human body, known to support movements and lateral stability while walking.

    Juneil Park et al, Effect of hip abduction assistance on metabolic cost and balance during human walking. Science Robotics (2023). DOI: 10.1126/scirobotics.ade0876.

  • Dr. Krishna Kumari Challa

    High temperatures may have caused over 70,000 excess deaths in Europe in 2022

    The burden of heat-related mortality during the summer of 2022 in Europe may have exceeded 70,000 deaths according to a study .

    The authors of the study, published in The Lancet Regional Health—Europe, revised upwards initial estimates of the mortality associated with record temperatures in 2022 on the European continent. The study is titled "The effect of temporal data aggregation to assess the impact of changing temperatures in Europe: an epidemiological modelling study."

    Ballester J et al, The effect of temporal data aggregation to assess the impact of changing temperatures in Europe: an epidemiological modelling study, The Lancet Regional Health—Europe (2023). DOI: 10.1016/j.lanepe.2023.100779

  • Dr. Krishna Kumari Challa

    Babies as young as four months show signs of self-awareness: Study

    Babies as young as four months old can make sense of how their bodies interact with the space around them, according to new research.

    The findings, published in Scientific Reports, shed new light on how self-awareness develops. Experts  showed babies a ball on a screen moving towards or away from them. When the ball was closest to them on the screen, the babies were presented with a 'touch' (a small vibration) on their hands while their brain activity was being measured.  The researchers found that from just four months old, babies show enhanced somatosensory (tactile) brain activity when a touch is preceded by an object moving toward them.

    These findings indicate that even in the first few months of life, before babies have even learned to reach for objects, the multisensory brain is wired up to make links between what babies see and what they feel. This means they can sense the space around them and understand how their bodies interact with that space. This is sometimes referred to as peripersonal space.

    Of course, humans do this all the time as adults, using our combined senses to perceive where we are in space and making predictions about when we will touch an object or not. But now that we know that babies in the early stages of their development begin to show signs of this, it opens up questions about how much of these abilities are learned or innate.

    Visual objects approaching the body modulate subsequent somatosensory processing at 4 months of age, Scientific Reports (2023). DOI: 10.1038/s41598-023-45897-4

  • Dr. Krishna Kumari Challa

    Unearthing how a carnivorous fungus traps and digests worms

    A new analysis sheds light on the molecular processes involved when a carnivorous species of fungus known as Arthrobotrys oligospora senses, traps and consumes a worm. 

    A. oligospora usually derives its nutrients from decaying organic matter, but starvation and the presence of nearby worms can prompt it to form traps to capture and consume worms. A. oligospora is just one of many species of fungi that can trap and eat very small animals.

    When A. oligospora first senses a worm, the findings suggest, DNA replication and the production of ribosomes (structures that build proteins in a cell) both increase. Next, the activity increases of many genes that encode proteins that appear to assist in the formation and function of traps, such as secreted worm-adhesive proteins and a newly identified family of proteins dubbed "trap enriched proteins" (TEP).

    Finally, after A. oligospora has extended filamentous structures known as hyphae into a worm to digest it, the activity is boosted by genes coding for a variety of enzymes known as proteases—in particular, a group known as metalloproteases. Proteases break down other proteins, so these findings suggest that A. oligospora uses proteases to aid in worm digestion.

    These findings could serve as a foundation for future research into the molecular mechanisms involved in A. oligospora predation and other fungal predator-prey interactions.

    Lin H-C, de Ulzurrun GV-D, Chen S-A, Yang C-T, Tay RJ, Iizuka T, et al. (2023) Key processes required for the different stages of fungal carnivory by a nematode-trapping fungus. PLoS Biology (2023). DOI: 10.1371/journal.pbio.3002400

  • Dr. Krishna Kumari Challa

    How bloodstain 'tails' can point to significant, additional forensic details

    Most of us know that evidence left at a crime scene, such as blood, can often reveal information that is key to investigating and understanding the circumstances around a crime—and that scientific methods can help interpret that information.

    In the journal Physics of Fluids, a group of scientists   demonstrated how bloodstains can yield even more valuable details than what is typically gathered by detectives, forensic scientists, and crime scene investigators. By examining the protrusions that deviate from the boundaries of otherwise elliptical bloodstains, the researchers studied how these "tails" are formed. The article is titled "Bloodstain tails: Asymmetry aids reconstruction of oblique impact".

    These protrusions are typically only used to get a sense of the direction that the drop traveled, but are otherwise neglected.

    In fact, previous studies have primarily focused on larger blood drops falling vertically on flat surfaces or on inclined surfaces where gravity can reshape and obscure the tails. By contrast, the new study involved a series of high-speed experiments with human blood droplets with diameters of less than a millimeter impacting horizontal surfaces at various angles.

    This new study shows that  the precise flow that determines the tail length differs from the flow responsible for the size and shape of the elliptical portion of the stain. "In other words, the tail lengths encompass additional independent information that can help analysts reconstruct where the blood drop actually came from."

    Indeed, the tail length can reflect information about the size, impact speed, and impact angle of the blood drop that formed the stain. When measured for several blood stains in a stain pattern, the trajectories of the drops can be backtracked to their presumed origin.

    Incorporating tail length into standard bloodstain analyses will produce more robust evidentiary information.

    "Knowing the origin of the blood stains at a crime scene can help detectives determine whether a victim was standing or sitting, or help corroborate or question a witness's testimony.

    Garam Lee et al, Bloodstain tails: Asymmetry aids reconstruction of oblique impact, Physics of Fluids (2023). DOI: 10.1063/5.0170124

  • Dr. Krishna Kumari Challa

    Gut microbes help alleviate constipation

    Scientists have identified the genes in the probiotic Bifidobacteria longum responsible for improving gut motility. A research team reporting November 21 in the journal Cell Host & Microbe found that B. longum strains possessing the abfA cluster of genes can ameliorate constipation through enhanced utilization of an indigestible fiber called arabinan in the gut.

    The researchers established the causal link between a genetic variant—the abfA cluster—to the key functional difference of probiotic B. longum in multiple model organisms, including mice and humans, and provided mechanistic and ecological insights into how a single gene cluster can affect the gut motility of hosts through arabinan metabolism.

    Peter Kuffa et al, Fiber-deficient diet inhibits colitis through the regulation of the niche and metabolism of a gut pathobiont, Cell Host & Microbe (2023). DOI: 10.1016/j.chom.2023.10.016

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    Solar panels vs planting forests: Which reduces climate change faster?

    Photovoltaic fields outperform afforestation as a global climate-change mitigation strategy, according to a study published in the journal PNAS Nexus.

  • Dr. Krishna Kumari Challa

    The World Is Running Out of Male Sea Turtles

    Green sea turtles are already an endangered species, mainly due to humans hunting them, harvesting their eggs, degrading their habitats, or entangling them in garbage (fishing nets) of some kind.

    But they also face another, more insidious threat from people: the loss of male hatchlings from the species.

    You probably already know that this is partly caused by rising temperatures due to climate change – but a new study has now unveiled another human-caused problem driving this trend.

    Certain pollutants may promote feminization in sea turtles. New research work  shows that the risk of extinction due to a lack of male green sea turtles may be compounded by contaminants that may also influence the sex ratio of developing green sea turtles, increasing the bias towards females.

    Green sea turtles (Chelonia mydas) have a vast geographical range, inhabiting tropical, subtropical, and temperate regions of the Atlantic, Pacific, and Indian oceans, as well as the Mediterranean Sea.

    Male hatchlings are now heavily outnumbered by females overall, although the degree of imbalance varies in different parts of their range. In some warmer places like the northern Great Barrier Reef, researchers say, hundreds of female turtles are now born for every male.
    That's because sea turtles use temperature-dependent sex determination, meaning an embryo's sex is determined by sand temperatures around its egg in the nest, with warmer sand favoring females. As temperatures rise around the world, male hatchlings are growing scarce. But that's not the only factor involved in determining sex, the latest research suggests.
    Part 1
  • Dr. Krishna Kumari Challa

    During this research work, when the hatchlings emerged, researchers recorded their sex and tested them for 18 heavy metals like cadmium and chromium, plus organic pollutants like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs).

    These contaminants are all known or suspected to function as 'xenoestrogens' or molecules that bind to the receptors for female sex hormones. Female turtles accumulate these contaminants at their foraging sites. As eggs develop within her, they absorb the contaminants that she accumulated and sequester them in the liver of the embryos, where they can stay for years after hatching.

    the study found varying sex ratios among the different clutches, but most nests yielded predominantly female hatchlings, the researchers report.

    And the degree of female bias in each nest showed an association with xenoestrogen levels in the hatchlings, they discovered: higher pollutant levels in hatchlings' livers correlated with a greater female bias in their nest.

    More research is still needed to clarify whether these pollutants are contributing to differences in sex ratio, but the association already warrants concern, researchers say.

    https://www.frontiersin.org/articles/10.3389/fmars.2023.1238837/full

    Part 2

  • Dr. Krishna Kumari Challa

    Chlorine disinfectant is no more effective than water at killing off hospital superbug, new study shows

    One of the primary chlorine disinfectants currently being used to clean hospital scrubs and surfaces does not kill off the most common cause of antibiotic-associated sickness in health care settings globally, according to a new study.

    Research has shown that spores of Clostridioides difficile, commonly known as C. diff, are completely unaffected despite being treated with high concentrations of bleach used in many hospitals. In fact, the chlorine chemicals are no more effective at damaging the spores when used as a surface disinfectant—than using water with no additives. Writing in the journal Microbiology, the study's authors say susceptible people working and being treated in clinical settings might be unknowingly placed at risk of contracting the superbug.

    As a result, and with incidence of biocide overuse only serving to fuel rises in antimicrobial resistance (AMR) worldwide, they have called for urgent research to find alternative strategies to disinfect C. diff spores in order to break the chain of transmission in clinical environments.

     Clostridioides difficile spores tolerate disinfection with Sodium hypochlorite disinfectant and remain viable within surgical scrubs and gown fabrics, Microbiology (2023). DOI: 10.1099/mic.0.001418

  • Dr. Krishna Kumari Challa

    This sea worm's posterior swims away, and now scientists know how

    Life always finds ways to surprise us. The presence of a unique reproductive mechanism in some annelid worms or segmented worms is one such surprise. In a process called stolonization, the posterior body part with gonads of the syllid worm detaches from its original body. The detached part is called the stolon, and it is full of gametes (eggs or sperm).

    The stolon swims around by itself and spawns when it meets the opposite sex. Swimming autonomously would not only protect the original body from environmental dangers but could also help its gametes disperse over larger distances.

    To swim autonomously, the stolons develop their own eyes, antennae, and swimming bristles while still attached to their original body. But how does the stolon head form in the middle of the original body?

    Part 1

  • Dr. Krishna Kumari Challa

    Careful histological and morphological observations revealed that the stolon formation starts with the maturation of gonads in the posterior end. Then forms a head in the anterior part of the developing stolon. Sense organs such as eyes and antennae, and swimming bristles form soon after. Before the stolon detaches, it develops nerves and a 'brain' to sense and behave independently.

    To understand the development of stolon's head, researchers investigated the developmental gene expression patterns of the sexually maturing worms. A well-known group of head formation genes are known to define the head region of various animals. They found that these genes are expressed more in the head region of the stolon. Typically, the head formation genes are not expressed as much in the middle of the body. But during gonad development in syllids, head formation genes are highly expressed in the middle of the posterior end of the original body.

    This shows how normal developmental processes are modified to fit the life history of animals with unique reproductive styles.

    Morphological, Histological and Gene-Expression Analyses on Stolonization in the Japanese Green Syllid, Megasyllis nipponica (Annelida, Syllidae), Scientific Reports (2023). DOI: 10.1038/s41598-023-46358-8

    Part 2

  • Dr. Krishna Kumari Challa

    Researchers pinpoint brain area where people who are blind recognize faces identified by sound

    Using a specialized device that translates images into sound, neuroscientists  showed that people who are blind recognized basic faces using the part of the brain known as the fusiform face area, a region that is crucial for the processing of faces in sighted people.

    It's been known for some time that people who are blind can compensate for their loss of vision, to a certain extent, by using their other senses.

    This study tested the extent to which this plasticity, or compensation, between seeing and hearing exists by encoding basic visual patterns into auditory patterns with the aid of a technical device researchers refer to as a sensory substitution device. With the use of functional magnetic resonance imaging (fMRI), they can determine where in the brain this compensatory plasticity is taking place.

    Face perception in humans and nonhuman primates is accomplished by a patchwork of specialized cortical regions. How these regions develop has remained controversial. Due to their importance for social behavior, many researchers think that the neural mechanisms for face recognition are innate in primates or depend on early visual experience with faces.

    The new results  from people who are blind imply that fusiform face area development does not depend on experience with actual visual faces but on exposure to the geometry of facial configurations, which can be conveyed by other sensory modalities.

    Josef Rauschecker et al, Sound-encoded faces activate the left fusiform face area in the early blind, PLoS ONE (2023). journals.plos.org/plosone/arti … journal.pone.0286512

  • Dr. Krishna Kumari Challa

    Wi-Fi for nerve signals
    Researchers have charted a long-distance ‘wireless’ nerve network in Caenorhabditis elegans worms for the first time. The nervous system can be thought of as a web of neurons that pass on messages through direct links, called synapses. But neurons can also communicate over longer distances by releasing molecules called neuropeptides, which are intercepted by other neurons some distance away. Incorporating both ‘wired’ synaptic connections and wireless signalling better predicts how signals travel in the worm than does a model using synaptic connections alone.

    https://www.nature.com/articles/d41586-023-03619-w?utm_source=Live+...

    Randi, F., Sharma, A. K., Dvali, S. & Leifer, A. M. Nature 623, 406–414 (2023).

    Ripoll-Sánchez, L. et al. Neuron 111, 3570–3589 (2023).

    Wang, H. et al. Science 382, eabq8173 (2023).

  • Dr. Krishna Kumari Challa

    How to keep polio from coming back

    Poliovirus is close to being eliminated: it could be gone within three years. But eradication is not extinction. The next challenge will be keeping it at bay. In rare cases, the oral poliovirus vaccine can itself seed a polio outbreak. But withdrawing that vaccine will leave people unprotected. The inactivated poliovirus vaccine doesn’t have the same flaw, but it doesn’t block transmission, so a broad vaccination programme would have to continue. And we will have to be sure that polio can never escape from a research institute or vaccine-manufacturing facility. Finally, a very tiny — but unknown — number of people have immune-deficiency disorders that mean they can carry and spread polio without knowing it, for years.

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    Study uncovers no compelling evidence that air purifiers prevent re...

    The COVID pandemic led to many calls for improved indoor air quality with claims that doing so would reduce the risk of the virus spreading. However, the real-world evidence to support these claims has been lacking, and studies undertaken during the pandemic have not yet been reported.

  • Dr. Krishna Kumari Challa

    Space Communication: beaming messages via laser

    Beaming messages via laser across a distance of almost 16 million kilometers or 10 million miles is no longer fiction.

    That's about 40 times farther than the Moon is from Earth, and it's the first time that optical communications have been sent across such a distance. Traditionally, we use radio waves to talk to distant spacecraft – but higher frequencies of light, such as near infrared, offer an increase in bandwidth and therefore a huge boost in data speed. If we're going to be able to send high-definition video messages to and from Mars without a significant delay, then this is the tech we need. The test is part of NASA's Deep Space Optical Communications (DSOC) experiment, and the successful establishment of the comms link is known as 'first light'.

    https://www.jpl.nasa.gov/missions/deep-space-optical-communications...

  • Dr. Krishna Kumari Challa

    Study shows plants use air channels to create a directional light signal and regulate phototropism

    Plants have no visual organs, so how do they know where light comes from? In an original study combining expertise in biology and engineering, scientists  uncovered that a light-sensitive plant tissue uses the optical properties of the interface between air and water to generate a light gradient that is "visible" to the plant. These results have been published in the journal Science.

    The majority of living organisms (micro-organisms, plants and animals) have the ability to determine the origin of a light source, even in the absence of a sight organ comparable to the eye. This information is invaluable for orienting oneself or optimal positioning in the environment.

    Perceiving where light is coming from is particularly important for plants, which use this information to position their organs, a phenomenon known as phototropism. This enables them to capture more of the sun's rays, which they then convert into chemical energy through the process of photosynthesis, a vital process that is necessary for the production of nearly all of the food we eat.

    Although the photoreceptor that initiates phototropism has long been known, the optical properties of photosensitive plant tissue have until now remained a mystery. A multidisciplinary study uncovered a surprising tissue feature allowing plants to detect directional light cues.

    Part 1

  • Dr. Krishna Kumari Challa

    It all started with the observation of a mutant of the model species Arabidopsis thaliana, the thale cress, whose stem was surprisingly transparent.

     These plants failed to respond to light correctly. The  biologists in the group then decided to call on the skills of their  colleagues in other fields in order to further compare the specific optical properties of the mutant versus wild-type samples.

    They found that the natural milky appearance of the stems of young wild plants was in fact due to the presence of air in intercellular channels precisely located in various tissues. In the mutant specimens, the air is replaced by an aqueous liquid, giving them a translucent appearance.

    But what purpose do such air-filled channels serve? They enable the photosensitive stem to establish a light gradient that can be "read" by the plant. The plant can then determine the origin of the light source. This phenomenon is due to the different optical properties of air and water, which make up the majority of living tissue.

    More specifically, air and water have different refractive indices. This leads to light scattering as it passes through the seedling.

    Thanks to their research, the scientists have revealed a novel mechanism that enables living organisms to perceive where the light is coming from, enabling them to position their organs such as leaves in a way that optimizes light capture for photosynthesis. The study also provided a better understanding of the formation of air-filled intercellular channels, which have a range of functions in plants, in addition to the formation of light gradients.

    Ganesh M. Nawkar et al, Air channels create a directional light signal to regulate hypocotyl phototropism, Science (2023). DOI: 10.1126/science.adh9384www.science.org/doi/10.1126/science.adh9384

    Part 2

  • Dr. Krishna Kumari Challa

    Biohybrid microrobots could remove micro- and nano-plastics from aquatic environments

    Micro and nano plastics are harmful tiny particles derived from the disintegration of plastic waste released into the water. These particles have been found to disrupt aquatic ecosystems, for instance, delaying the growth of organisms, reducing their food intake, and damaging fish habitats.

    Devising effective technologies to effectively remove these tiny particles is of utmost importance, as it could help to protect endangered species and their natural environments. These technologies should be carefully designed to prevent further pollution and destruction; thus, they should be based on environmentally friendly materials.

    Researchers recently developed biohybrid microrobots that could remove micro- and nano-plastics from polluted water without causing further pollution. These robots, presented in a paper published in Advanced Functional Materials, integrate biological materials, specifically algae, with environmentally friendly materials that respond to external magnetic fields. 

    The new robots they created, dubbed magnetic algae robots (MARs), consist of a combination of algae and environmentally friendly magnetic nanoparticles.

    These robots operate under the influence of an external magnetic field, enabling precise control over their movement. The negative surface charge of MARs is attributed to the presence of -COOH groups on the surface of algae cells. In contrast, the selected micro/nano plastics carry a positive surface charge. This positive-negative interaction facilitates electrostatic attraction, thereby promoting the targeted capture and removal of micro/nano plastics by the MARs.

    The unique composition of the robots created by the researchers makes them both non-polluting and responsive to externally applied magnetic fields. This could allow them to sustainably retrieve nano- and micro-sized plastic particles from aquatic environments.

     Xia Peng et al, Biohybrid Magnetically Driven Microrobots for Sustainable Removal of Micro/Nanoplastics from the Aquatic Environment, Advanced Functional Materials (2023). DOI: 10.1002/adfm.202307477

  • Dr. Krishna Kumari Challa

    Reactivating silenced fetal hemoglobin genes could counter sickle cell–related diseases

    Researchers from multiple institutions  have found a way to use gene editing to reactivate dormant fetal oxygen-transporting proteins in adult blood cells to potentially reverse a wide range of blood disorders.

    In a paper, "Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs," published in Cell Stem Cell, the team compares gene editing techniques while formulating a method that could have important clinical applications.

    Fetal gamma (γ) globin is normally replaced by adult (β) hemoglobin during development. In an odd quirk of evolution, only humans and a few types of monkeys are known to switch from γ to β gene expression. The genes producing the fetal hemoglobin become silenced and dormant after the genetic switch by repressors such as BCL11A and ZBTB7A, whose binding motifs have been identified as targets for reactivation. β-hemoglobinopathies, including β-thalassemia and sickle cell disease, result from mutations in the HBB gene, leading to impaired β-globin production and resulting in anemia, impaired oxygen delivery to tissues and possible multi-organ tissue damage. The researchers experimentally discovered that reactivating γ-globin expression could be developed into a universal therapeutic strategy for these conditions.

    Wenyan Han et al, Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs, Cell Stem Cell (2023). DOI: 10.1016/j.stem.2023.10.007

  • Dr. Krishna Kumari Challa

    Plastic waste in the water might be stopping, or interrupting, some shrimp-like creatures from reproducing
    In a unique study, published in the journal Environmental Pollution,the ability of "shrimp-like" creatures to reproduce successfully was found to be compromised by chemicals found in everyday plastics.

    Research showed that little critters, known as marine amphipod Echinogammarus marinus, changed their mating behavior when exposed to toxic plastic additives.

    Until now, most research into plastic pollution has focused on visual plastics; what can get trapped in plastics and the dangers of ingesting large particles. Scientists now have taken a different approach and investigated the chemicals that are used as ingredients in plastics.
    This unsuccessful mating behavior has serious repercussions, not only for the species being tested but potentially for the population as a whole. These animals form pairs to reproduce. Once they were exposed to a chemical, they would break apart from their mate and take much longer—in some cases days—to re-pair, and sometimes not at all.
    These creatures make up a substantial amount of the diet of fish and birds. If they are compromised it will have an effect on the whole food chain.
    There are more than 350,000 chemicals in use around the world in everyday products. Ten thousand of these are used to enhance plastics. Chemicals can be used to make plastics more flexible, add color, give sun protection or make plastic flameproof. About one-third of these chemicals are known to be toxic to human's immune, nervous or reproductive systems.
    Although the animals we tested were exposed to much higher concentrations than you would normally find in the environment, the results indicate these chemicals can affect sperm count.

    Bidemi Green-Ojo et al, Evaluation of precopulatory pairing behaviour and male fertility in a marine amphipod exposed to plastic additives, Environmental Pollution (2023). DOI: 10.1016/j.envpol.2023.122946

  • Dr. Krishna Kumari Challa

    Death by Stem Cell: Developing New Cancer Therapies

    Engineering stem cells to deliver cancer therapeutics directly to tumors, thereby increasing their efficacy.

    While chemotherapy, surgery, and radiation therapy are traditional cancer treatments that can be applied individually or in combination, a patient’s response to these approaches depends on cancer type, location, heterogeneity, and drug resistance.2 Consequently, researchers need to develop novel therapies and delivery methods.

    Some researchers are developing cancer therapeutics that use stem cells as delivery vectors to treat primary and metastatic brain and lung cancers. In a recently published Science Translational Medicine paper, some of them  showed an allogeneic twin stem cell system carrying oncolytic viral particles and immunomodulators to treat brain metastases.  A few weeks later, they also published a Stem Cells Translational Medicine paper, where they engineered mesenchymal stem cells to secrete a bi-functional molecule targeting two receptors in lung tumors, leading to cancer cell death.

    1. Siegel RL, et al. Cancer statistics, 2023. CA Cancer J Clin. 2023;73(1):17-48.
    2.  Debela DT, et al. New approaches and procedures for cancer treatment: Current perspec.... SAGE Open Med. 2021;9.
    3.  Kanaya N, et al. Gene-edited and -engineered stem cell platform drives immunotherapy.... Sci Transl   Med. 2023;15(698):eade8732.
    4.  Moleirinho S, et al. Fate and efficacy of engineered allogeneic stem cells targeting cel.... Stem Cells Transl Med. 2023;12(7):444-458.
  • Dr. Krishna Kumari Challa

    Scientists Find 'Kill Switch' That Activates Cancer Cell Death in The Lab

    Scientists have figured out a way to detonate the 'doors' that lead to the heart of cancerous tumors, blowing them wide open for drug treatments.

    The strategy works by triggering a 'timer bomb' on the cells that line a tumor's associated blood vessels.

    These vessels control access to the tumor tissue, and until they are opened, engineered immune cells can't easily gain entry to the cancer to fight it off. The timer bomb on these cells is actually a 'death' receptor, called Fas (or CD95). When activated by the right antibody, it triggers the programmed death of that cell.

    In recent experiments using mouse models and human cell lines, scientists have at last identified specific antibodies that, when attached to Fas receptors, effectively trigger self-implosion. now that we've identified this epitope, there could be a therapeutic path forward to target Fas in tumors. The antibody that binds to this epitope (a specific part of the death receptor), essentially represents the kill switch for the cell. Once this immune checkpoint is blown open, other cancer therapies, like CAR-T therapy, can gain access to more of their targets, which are often clumped together and hidden within the tumor. CAR-T therapy works by programming a person's own white blood cells, called T-cells, to bind to and attack specific types of cancerous cells. These tailored immune cells, however, cannot usually get past the 'bystander' cells that lack the recognisable antigens usually used to target tumor cells. As a result, CAR-T therapy has only been approved to treat blood cancers or leukemia. It fails to provide consistent success against solid tumors till now. In recent experiments , scientists developed two engineered antibodies that were "supremely effective" at attaching to Fas receptors and causing bystander cells to self-implode. This was true in ovarian cancer models and many other tumor cell lines tested in the lab. The Fas ligand developed by researchers was able to engage two critical parts of the Fas receptor, which researchers say should be investigated further. These parts hold potential as future drug targets.

    https://www.nature.com/articles/s41418-023-01229-7

  • Dr. Krishna Kumari Challa

    Scientists finally work out what causes itching

  • Dr. Krishna Kumari Challa

    The bilingual brain may be better at ignoring irrelevant information

    People who speak two languages may be better at shifting their attention from one thing to another compared to those who speak one, according to a study published this month in the journal Bilingualism: Language and Cognition.

    The study examined differences between bilingual and monolingual individuals when it comes to attentional control and ignoring information that isn't important at the time. 

    Our results showed that bilinguals seem to be more efficient at ignoring information that's irrelevant, rather than suppressing—or inhibiting information. One explanation for this is that bilinguals are constantly switching between two languages and need to shift their attention away from the language not in use.

    For example, if an English- and Spanish-speaking person is having a conversation in Spanish, both languages are active, but English is put on hold but always ready to be deployed as needed. Numerous studies have examined the distinctions between the two groups in broad cognitive mechanisms, which are mental processes that our brains use, like memory, attention, problem-solving, and decision-making.

    The effects of speaking two languages on a person's cognitive control is often debated. Some of the literature says these differences aren't so pronounced, but that could be because of the tasks linguists use to research differences between bilinguals and monolinguals.

    Now what about people who can speak several languages?

    Grace deMeurisse et al, Bilingual attentional control: Evidence from the Partial Repetition Cost paradigm, Bilingualism: Language and Cognition (2023). DOI: 10.1017/S1366728923000731

  • Dr. Krishna Kumari Challa

    Bacteria store 'memories' and pass them on for generations, study finds

    Scientists have discovered that bacteria can create something like memories about when to form strategies that can cause dangerous infections in people, such as resistance to antibiotics and bacterial swarms when millions of bacteria come together on a single surface. The discovery—which has potential applications for preventing and combatting bacterial infections and addressing antibiotic-resistant bacteria—relates to a common chemical element bacterial cells can use to form and pass along these memories to their progeny over later generations.

    Researchers found that E. coli bacteria use iron levels as a way to store information about different behaviours that can then be activated in response to certain stimuli.

    Scientists had previously observed that bacteria that had a prior experience of swarming (moving on a surface as a collective using flagella) improve subsequent swarming performance.

    Bacteria don't have neurons, synapses or nervous systems, so any memories are not like the ones we have. They are more like information stored on a computer.

    Bacteria don't have brains, but they can gather information from their environment, and if they have encountered that environment frequently, they can store that information and quickly access it later for their benefit.

    It all comes back to iron, one of the most abundant elements on Earth. Singular and free-floating bacteria have varying levels of iron. Scientists observed that bacterial cells with lower levels of iron were better swarmers. In contrast, bacteria that formed biofilms, dense, sticky mats of bacteria on solid surfaces, had high levels of iron in their cells. Bacteria with antibiotic tolerance also had balanced levels of iron. These iron memories persist for at least four generations and disappear by the seventh generation.

    Before there was oxygen in the Earth's atmosphere, early cellular life was utilizing iron for a lot of cellular processes. Iron is not only critical in the origin of life on Earth, but also in the evolution of life. It makes sense that cells would utilize it in this way.

    Souvik Bhattacharyya et al, A heritable iron memory enables decision-making in Escherichia coli, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2309082120

  • Dr. Krishna Kumari Challa

    Study unveils the engagement of different cortical networks while humans are unconscious

    States of unconsciousness, such as those that occur during sleep or while under the effect of anesthesia, have been the focus of countless past neuroscience studies. While these works have identified some brain regions that are active and inactive when humans are unconscious, the precise contribution of each of these regions to consciousness remains largely unclear.

    Researchers recently carried out a study aimed at better understanding the activity of different regions of the cortex, the outer layer of the mammalian brain, during different states of unconsciousness, namely sleep and general anesthesia. Their paper, published in Neuron, identifies distinct cortical networks that are engaged during different states of unconsciousness.

    What happens in the human brain when we are unconscious? And, what happens when we cannot be awakened?

    This recent study on the states of unconsciousness focuses on sleep versus general anesthesia induced by the drug propofol.

    The researchers carried out their study on patients diagnosed with epilepsy who had electrodes implanted in their brains as part of their medical treatment. By recording brain activity inside the brain, these electrodes help doctors monitor and treat epileptic seizures. 

    They found that, compared to when they were awake, during sleep the brain was uniformly affected across patients, presenting simpler and reduced brain connections, as well as larger variability in the recorded activity.

    All measures were more pronounced during propofol-induced anesthesia, but the brain involvement was not uniform; the changes in prefrontal regions were particularly prominent.

    This indicates that during different forms of unconsciousness distinct parts of the brain are involved in different ways. These new findings in turn imply that going from unconscious to conscious may use different mechanisms depending on the nature of the unconscious state.

     Rina Zelmann et al, Differential cortical network engagement during states of un/consciousness in humans, Neuron (2023). DOI: 10.1016/j.neuron.2023.08.007

  • Dr. Krishna Kumari Challa

    Not just meteorite: New clues about the demise of dinosaurs

    What wiped out the dinosaurs? A meteorite plummeting to Earth is only part of the story, a new study suggests. Climate change triggered by massive volcanic eruptions may have ultimately set the stage for the dinosaur extinction, challenging the traditional narrative that a meteorite alone delivered the final blow to the ancient giants.

    Researchers delved into volcanic eruptions of the Deccan Traps—a vast and rugged plateau in Western India formed by molten lava. Erupting a staggering 1 million cubic kilometers of rock, it may have played a key role in cooling the global climate around 65 million years ago. The work took researchers around the world, from hammering out rocks in the Deccan Traps to analyzing the samples in England and Sweden. 

    In the lab, the scientists estimated how much sulfur and fluorine was injected into the atmosphere by massive volcanic eruptions in the 200,000 years before the dinosaur extinction.

    Remarkably, they found the sulfur release could have triggered a global drop in temperature around the world—a phenomenon known as a volcanic winter.

    The research demonstrates that climatic conditions were almost certainly unstable, with repeated volcanic winters that could have lasted decades, prior to the extinction of the dinosaurs. This instability would have made life difficult for all plants and animals and set the stage for the dinosaur extinction event. 

    Sara Callegaro et al, Recurring volcanic winters during the latest Cretaceous: Sulfur and fluorine budgets of Deccan Traps lavas, Science Advances (2023). DOI: 10.1126/sciadv.adg8284

  • Dr. Krishna Kumari Challa

    How climate change impacts health

    Extreme heat, air pollution and the increasing spread of deadly infectious diseases are just some of the reasons why the World Health Organization has called climate change the single biggest health threat facing humanity.

    Global warming must be limited to the Paris Agreement target of 1.5 degrees Celsius "to avert catastrophic health impacts and prevent millions of climate change-related deaths", according to the WHO.

    However, under current national carbon-cutting plans, the world is on track to warm up to 2.9°C this century, the UN said this week.

    While no one will be completely safe from the effects of climate change, experts expect that most at risk will be children, women, the elderly, migrants and people in less developed countries which have emitted the least planet-warming greenhouse gases.

    This year is widely expected to be the hottest on record. And as the world continues to warm, even more frequent and intense heat waves are expected to follow.

    Part 1

  • Dr. Krishna Kumari Challa

    Heat is believed to have caused more than 70,000 deaths in Europe during summer last year, researchers said this week, revising the previous number up from 62,000.

    Worldwide, people were exposed to an average of 86 days of life-threatening temperatures last year, according to The Lancet Countdown report earlier this week.

    The number of people over 65 who died from heat rose by 85 percent from 1991-2000 to 2013-2022, it added.

    And by 2050, more than five times more people will die from the heat each year under a 2°C warming scenario, The Lancet Countdown projected.

    More droughts will also drive rising hunger. Under the scenario of 2°C warming by the end of the century, 520 million more people will experience moderate or severe food insecurity by 2050.

    Meanwhile, other extreme weather events such as storms, floods and fires will continue to threaten the health of people across the world.

    Part 2

  • Dr. Krishna Kumari Challa

    Almost 99 percent of the world's population breathes air that exceeds the WHO's guidelines for air pollution.

    Outdoor air pollution driven by fossil fuel emissions kills more than four million people every year, according to the WHO.

    It increases the risk of respiratory diseases, strokes, heart disease, lung cancer, diabetes and other health problems, posing a threat that has been compared to tobacco.

    The damage is caused partly by PM2.5 microparticles, which are mostly from fossil fuels. People breathe these tiny particles into their lungs, where they can then enter the bloodstream.

    While spikes in air pollution, such as extremes seen in India's capital New Delhi earlier this month, trigger respiratory problems and allergies, long-term exposure is believed to be even more harmful.

    The changing climate means that mosquitoes, birds and mammals will roam beyond their previous habitats, raising the threat that they could spread infectious diseases with them.

    Mosquito-borne diseases that pose a greater risk of spreading due to climate change include dengue, chikungunya, Zika, West Nile virus and malaria.

    The transmission potential for dengue alone will increase by 36 percent with 2°C warming, The Lancet Countdown report warned.

    Storms and floods create stagnant water that are breeding grounds for mosquitoes, and also increase the risk of water-borne diseases such as cholera, typhoid and diarrhea.

    Scientists also fear that mammals straying into new areas could share diseases with each other, potentially creating new viruses that could then jump over to humans.

    Part 3

  • Dr. Krishna Kumari Challa

    Worrying about the present and future of our warming planet has also provoked rising anxiety, depression and even post-traumatic stress—particularly for people already struggling with these disorders, psychologists have warned.

    In the first 10 months of the year, people searched online for the term "climate anxiety" 27 times more than during the same period in 2017, according to data from Google Trends cited by the BBC this week.

    Source: 

    The Lancet and AFP

    Part 4

  • Dr. Krishna Kumari Challa

    Chocolate discharges the same chemical in your body as when you feel love.
    Chocolate raises levels of phenylethylamine (PEA), “the love chemical”. This chemical gets our hearts pumping, increases blood pressure, heart, and respiratory rates, and increases feelings of joy
    Chocolate releases this neurochemical of pleasure in our brains. Dopamine kick starts a brain messenger chemical called DARP-32 that activates hormones. This is the chemical that surges through us when we are embraced by someone we love.
    Chocolate contains tryptophan, a precursor to serotonin. Serotonin is our other feel good chemical. It diminishes anxiety and increases our ability to fight stress. Many antidepressants work by increasing serotonin levels.
    So those who are not in love go eat chocolates and be happy.

  • Dr. Krishna Kumari Challa

    How to make waves eat themselves
    Physicists have demonstrated that two cavities carved into the side of a channel can totally dissipate the energy of incoming waves. In a model set-up with real water, researchers were able to achieve ‘perfect absorption’ — in which the waves completely cancelled themselves out as they bounced off the cavity walls — with waves of a frequency of 2.9 Hertz. The finding hints at the possibility of designing structures to protect coastlines or harvest wave energy.

    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.204002

  • Dr. Krishna Kumari Challa

    Meta AI develops a non-invasive method to decode speech from brain activity

    Recent technological advancements have opened invaluable opportunities for assisting people who are experiencing impairments or disabilities. For instance, they have enabled the creation of tools to support physical rehabilitation, to practice social skills, and to provide daily assistance with specific tasks.

    Recent technological advancements have opened invaluable opportunities for assisting people who are experiencing impairments or disabilities. For instance, they have enabled the creation of tools to support physical rehabilitation, to practice social skills, and to provide daily assistance with specific tasks. Researchers at Meta AI recently developed a promising and non-invasive method to decode speech from a person's brain activity, which could allow people who are unable to speak to relay their thoughts via a computer interface. Their proposed method, presented in Nature Machine Intelligence, merges the use of an imaging technique and machine learning.

    Alexandre Défossez et al, Decoding speech perception from non-invasive brain recordings, Nature Machine Intelligence (2023). DOI: 10.1038/s42256-023-00714-5.

  • Dr. Krishna Kumari Challa

    Scientists discover rare six-planet system that moves in strange synchrony

    Scientists have discovered a rare sight in a nearby star system: Six planets orbiting their central star in a rhythmic beat. The planets move in an orbital waltz that repeats itself so precisely that it can be readily set to music.

    A rare case of an "in sync" gravitational lockstep, the system could offer deep insight into planet formationand evolution.

    The analysis, led by UChicago scientist Rafael Luque, was published Nov. 29 in Nature.

    The six planets orbit a star known as HD110067, which lies around 100 light-years away in the northern constellation of Coma Berenices.

    In 2020, NASA's Transiting Exoplanet Survey Satellite (TESS) detected dips in the star's brightness that indicated planets were passing in front of the star's surface. Combining data from both TESS and the European Space Agency's CHaracterizing ExOPlanet Satellite (Cheops), a team of researchers analyzed the data and discovered a first-of-its-kind configuration.

    While multi-planet systems are common in our galaxy, those in a tight gravitational formation known as "resonance" are observed by astronomers far less often.

    In this case, the planet closest to the star makes three orbits for every two of the next planet out—called a 3/2 resonance—a pattern that is repeated among the four closest planets. Among the outermost planets, a pattern of four orbits for every three of the next planet out (a 4/3 resonance) is repeated twice.

    And these resonant orbits are rock-solid: The planets likely have been performing this same rhythmic dance since the system formed billions of years ago, the scientists said.

    Orbitally resonant systems are extremely important to find because they tell astronomers about the formation and subsequent evolution of the planetary system. Planets around stars tend to form in resonance but can be easily perturbed. For example, a very massive planet, a close encounter with a passing star, or a giant impact event can all disrupt the careful balance.

    As a result, many of the multi-planet systems known to astronomers are not in resonance but look close enough that they could have been resonant once. However, multi-planet systems preserving their resonance are rare.

    Rafael Luque, A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067, Nature (2023). DOI: 10.1038/s41586-023-06692-3www.nature.com/articles/s41586-023-06692-3

  • Dr. Krishna Kumari Challa

    Nanodiamonds can block tumor metastasis in mice, study shows

    Nanodiamonds are 2–8 nm carbon nanoparticles, which can be easily functionalized with various chemical groups like carboxylic groups or drugs. Previous research has shown that actively dividing cells are more likely to absorb nanodiamonds and that epithelial cells treated with carboxylic nanodiamonds lose the ability to migrate across cell-permeable cellulose membranes.

    Researchers explored whether nanodiamonds might block tumor metastasis, a process that requires cell migration to new areas. The research is published in the journal PNAS Nexus. 

    The authors treated B16F10 melanoma cells with carboxylic nanodiamonds in culture and tested their ability to migrate and invade across polycarbonate membranes with 8-µm pores. The authors found that the nanodiamonds blocked the ability of melanoma cells to migrate, while untreated tumor cells were able to pass through the membrane.

    Based on gene expression evidence, the authors hypothesize that the tiny carbon nanodiamonds may inhibit the breaking away of cancer cells from the primary tumor mass—as well as block subsequent steps of metastasis such as the physical movement of cells and their ability to enter blood vessels.

    According to the authors, nanodiamonds should be further explored as a possible therapeutic agent for cancer metastasis.

     Sushreesangita P Behera et al, Carboxyl nanodiamonds inhibit melanoma tumor metastases by blocking cellular motility and invasiveness, PNAS Nexus (2023). DOI: 10.1093/pnasnexus/pgad359

  • Dr. Krishna Kumari Challa

    Reducing fatal bird collisions

  • Dr. Krishna Kumari Challa

    A mineral produced by plate tectonics has a global cooling effect, study finds

    Geologists have found that a clay mineral on the seafloor, called smectite, has a surprisingly powerful ability to sequester carbon over millions of years.

    Under a microscope, a single grain of the clay resembles the folds of an accordion. These folds are known to be effective traps for organic carbon. 

    Now, the researchers have shown that the carbon-trapping clays are a product of plate tectonics: When oceanic crust crushes against a continental plate, it can bring rocks to the surface that, over time, can weather into minerals including smectite. Eventually, the clay sediment settles back in the ocean, where the minerals trap bits of dead organisms in their microscopic folds. This keeps the organic carbon from being consumed by microbes and expelled back into the atmosphere as carbon dioxide.

    Over millions of years, smectite can have a global effect, helping to cool the entire planet. Through a series of analyses, the researchers showed that smectite was likely produced after several major tectonic events over the last 500 million years. During each tectonic event, the clays trapped enough carbon to cool the Earth and induce the subsequent ice age.

    The findings are the first to show that plate tectonics can trigger ice ages through the production of carbon-trapping smectite.

    "Palaeozoic cooling modulated by ophiolite weathering through organic carbon preservation", Nature Geoscience (2023). DOI: 10.1038/s41561-023-01342-9

  • Dr. Krishna Kumari Challa

    Brain waves usually found in sleep can protect against epileptic activity

    Slow waves that usually only occur in the brain during sleep are also present during wakefulness in people with epilepsy and may protect against increased brain excitability associated with the condition, finds a new study by researchers.

    The researchers examined electroencephalogram (EEG) scans from electrodes in the brains of 25 patients with focal epilepsy (a type of epilepsy characterized by seizures arising from a specific part of the brain), while they carried out an associative memory task.

    The electrodes had been placed in the patients' brains to localize abnormal activity and inform surgical treatment.

    During the task, participants were presented with 27 pairs of images that remained on a screen for six seconds. The images were in nine groups of three—each group featuring a picture of a person, a place and an object. In each case, participants had to remember which images had been grouped together. EEG data were recorded continuously throughout the task.

    After reviewing the EEG data, the team found that the brains of people with epilepsy were producing slow waves—lasting less than one second—while they were awake and taking part in the task.

    The occurrence of these "wake" slow waves increased in line with increases in brain excitability and decreased the impact of epileptic spikes on brain activity.

    In particular, there was a decrease in the "firing" of nerve cells, which the researchers say could protect against epileptic activity.

    Wake slow waves in focal human epilepsy impact network activity and cognition, Nature Communications (2023). DOI: 10.1038/s41467-023-42971-3

  • Dr. Krishna Kumari Challa

    As dengue expands beyond the global 'dengue belt,' scientists dispel conventional wisdom about the disease

    Unknowns, dangers and surprises persist about dengue viral infection and now an assumption once accepted as conventional wisdom about immunity to the mosquito-borne disease may be incorrect.

    Dengue is a devastating viral infection transmitted to humans through the bite of Aedes aegypti mosquitoes—flying hypodermic needles that descend prolifically during significant outbreaks. Many dengue epidemics tend to occur in urban settings, scientists say. Dengue viral infection can cause a severe headache, high fever, nausea, vomiting, swollen glands, and rash. Still, and perhaps most surprisingly, many people who are infected have no symptoms at all. In rare cases, however, dengue disease can be fatal.

    New research involving epidemiological models and data from more than 4,400 people in Nicaragua suggests that it's time immunologists developed a new framework to understand population immunity to dengue. For decades, it was believed that once you were infected with dengue virus, the immunity lasted for life. The dogma persisted in the face of observational data, which found that people who were previously infected were more susceptible to severe dengue if infected again.

    But an international collaborative group of researchers has now conclusively shown that immunity not only wanes, it tends to wax and wane—a discovery that reveals dengue infection to be far more complex than previously thought.

    According to them, Infection with multiple dengue virus serotypes is thought to induce enduring protection against dengue disease. However, long-term antibody waning has been observed after repeated dengue infection. The waning of antibodies inevitably was followed by a boosting of antibodies when the next epidemic came along.

    This discovery allowed the construction of a new model that best describes population vulnerability to dengue infection, especially amid the known periodicity—the cyclic nature—of dengue outbreaks.

    When it comes to dengue, people are not permanently immune but susceptible to infection, then immune and ultimately susceptible again. Hence, the researchers  newly proposed a model: "susceptible-infected-recovered-susceptible."

    Rosemary A. Aogo et al, Effects of boosting and waning in highly exposed populations on dengue epidemic dynamics, Science Translational Medicine (2023). DOI: 10.1126/scitranslmed.adi1734

  • Dr. Krishna Kumari Challa

    New research suggests cellular stress in the placenta may be possible cause of preeclampsia

    Preeclampsia is a mysterious condition that occurs in about one of 10 pregnancies without any early warning signs. After 20 weeks or more of normal blood pressure during the pregnancy, patients with preeclampsia will begin to experience elevated blood pressure and may also have increased levels of protein in their urine due to hypertension reducing the filtering power of the kidneys. Prolonged hypertension due to preeclampsia can lead to organ damage and life-threatening complications for mothers and fetuses.

    There is no cure for the underlying causes of preeclampsia, so physicians focus on managing and monitoring patients' blood pressure to allow for as close to a full-term gestation as possible. With severe disease, pre-term deliveries are necessary.

    For those who get it earlier on, it can be terrifying and life-changing, potentially including a long hospital stay before delivery and significant supportive care for the infant in the NICU afterwards.

    Now scientists have published results on a study of one of the emerging theories for what causes preeclampsia in Science Advances.

    The experiments focus on a particular layer of cells of the placenta called the syncytiotrophoblast (STB), which is a key part of the barrier between the mother and developing fetus. This blockade helps keep a mother's fully formed immune system from reacting to the fetus and potentially responding as if the fetus was a foreign threat such as a viral or bacterial invader.

    The barrier also works in reverse to keep the fetus's growing immune system from reacting to its mother's cells and tissues. The study's authors investigated the hypothesis that an abnormal amount of cellular and molecular stresses to the STB can damage the placenta and lead to preeclampsia.

    Part 1

  • Dr. Krishna Kumari Challa

    By comparing "normal" placentas with placentas from pregnancies where patients suffered from preeclampsia, investigators demonstrated that preeclampsia was associated with higher levels of cellular stresses in the STB layer on the placenta. Additionally, the researchers found a hyperactive level of activity of the Gαq protein known to play a role in transmitting signals related to the levels of several hormones present in excessive amounts during preeclampsia.

    So, can preeclampsia be prevented? While today the answer is no, MCW scientists now are one step closer with these experimental results. And they are continuing to work as a team to achieve this goal through additional studies.

    Megan Opichka et al, Mitochondrial-Targeted Antioxidant Attenuates Preeclampsia-Like Phenotypes Induced by Syncytiotrophoblast-Specific Gαq Signaling, Science Advances (2023). DOI: 10.1126/sciadv.adg8118www.science.org/doi/10.1126/sciadv.adg8118

    Part 2

  • Dr. Krishna Kumari Challa

    New discovery: Stunning River of Stars Flowing Through Space

    A stunning river of stars has been spotted flowing through the intergalactic space in a cluster of galaxies about 300 million light years away.

    Such bridges are known as stellar streams; and, at a length of 1.7 million light-years, the newly named Giant Coma Stream is the longest we've ever seen. And that's not all: the faint river is the first of its kind ever seen outside of a galaxy.

    https://www.aanda.org/articles/aa/full_html/2023/11/aa46780-23/aa46...

  • Dr. Krishna Kumari Challa

    Dolphins can detect electrical fields

    Two captive bottlenose dolphins (Tursiops truncatus) have now proved to researchers at the University of Rostock and Nuremberg Zoo in Germany that they can reliably sense weak electric fields in the water with their long snouts.

    The discovery hints at the possibility that some marine mammals really can sniff out the electric currents of small prey buried in the sand. They might even use the skill to sense Earth's magnetic field.

    To date, only one other 'true' placental mammal on Earth has been found to possess electroreceptors. Little more than a decade ago, scientists demonstrated that the common Guiana dolphin (Sotalia guianensis) evolved its own unique system of electroreception – one that is inherently different to fish, amphibians, and monotremes, like platypuses and echidnas.

    Experiments now suggest that adult bottlenose dolphins and Guiana dolphins can both do something oddly similar with a line of sensitive pores on their snouts, called vibrissal crypts. These little holes used to hold juvenile whiskers, and they are extremely sensitive.

    In experiments, bottlenose dolphins were able to use these ex-whisker pits to sense very weak electric fields as low as 2.4 and 5.5 microvolts per centimeter – a detection threshold that the researchers say is "in the same order of magnitude as those in the platypus" and also similar to Guiana dolphins.

    https://journals.biologists.com/jeb/article/226/22/jeb245845/334721...

  • Dr. Krishna Kumari Challa

    Food Preserving Technique May Have Sparked Human Brain Growth: Researchers

    Researchers propose that a taste for fermented morsels may have triggered a surprising jump in the growth rate of our ancestors' brains.

    In fact, a shift from a raw diet to one that included food items already partially broken down by microbes may have been a crucial event in our brain's evolution, according to a perspective study by evolutionary neuroscientists.

    Human brains have tripled in size over the last two million years of evolution, while human colons have shrunk by an estimated 74 percent, suggesting a reduced need to break down plant-derived food internally.
    We know the timeline and extent of human brain expansion, but the mechanisms allowing energy to be directed to this expansion are more complex and somewhat debated.

    The study authors lay out their "external fermentation hypothesis" which shows our ancestors' metabolic circumstances for selective brain expansion may have been set in motion by moving intestinal fermentation to an external process, perhaps even experimenting with preserved foods not unlike the wine, kimchi, yoghurt, sauerkraut, and other pickles we still eat today.
    The human gut microbiome acts like a machine for internal fermentation, which boosts nutrient absorption during digestion. Organic compounds are fermented into alcohol and acids by enzymes, usually produced by the bacteria and yeasts that live in parts of our digestive system such as our colon.
    Fermentation is an anaerobic process, meaning it doesn't require oxygen, so similar to the process in our guts, it can occur in a sealed container. The process produces energy in the form of adenosine triphosphate (ATP), which is an essential source of chemical energy that powers our metabolism.

    The researchers argue it's possible that culturally passed-down ways of handling or storing food encouraged this function to be externalized.

    Externally fermented foods are easier to digest and contain more available nutrients than their raw equivalents. And since there's less for the colon to do if the food is already fermented, the organ's size could reduce over time while still potentially leaving energy available for brain growth.
    Part 1
  • Dr. Krishna Kumari Challa

    The brain sizes of our ancestors, the Australopiths, were similar to those of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). The human lineage's brain expansion accelerated with Homo's emergence and continued through Homo sapiens and Homo neanderthalensis.

    How did our ancestors, with brains about the size of chimpanzees, manage to harness the power of external fermentation?

    Researchers suggest that hominids with lower cognitive abilities and smaller brains may have adapted to fermentation much earlier than proposed alternative alternative explanations for this gut-to-brain energy redirection, like animal hunting and fire-based cooking.
    Fermentation has many advantages associated with cooked foods, such as softer textures, increased caloric content, improved nutrient absorption, and defense against harmful microorganisms.
    The researchers emphasize the need for empirical research to support or refute their hypothesis, such as microbiological studies, comparative analyses, and genetic and genomic investigations.

    https://www.nature.com/articles/s42003-023-05517-3

    Part 2

    **

  • Dr. Krishna Kumari Challa

    Brain implants revive cognitive abilities long after traumatic brain injury in clinical trial

    A lady in her final semester of college, planning to apply to law school, when she suffered a traumatic brain injury in a car accident. The injury so compromised her ability to focus she struggled in a job sorting mail.

    She couldn't remember anything . Her left foot dropped, so she'd trip over things all the time. She was always in car accidents. And she had no filter—she'd get pissed off really easily.

    Her parents learned about research being conducted at Stanford Medicine and reached out; she was accepted as a participant. In 2018, physicians surgically implanted a device deep inside her brain, then carefully calibrated the device's electrical activity to stimulate the networks the injury had subdued. The results of the clinical trial were published Dec. 4 in Nature Medicine. She noticed the difference immediately. When she was asked to list items in the produce aisle of a grocery store, she could rattle off fruits and vegetables. Then a researcher turned the device off, and she couldn't name any. Since the implant she hadn't  had any speeding tickets she said. She doesn't trip anymore. She can remember how much money is in her bank account. She  wasn't able to read earlier, but after the implant she bought a book, 'Where the Crawdads Sing,' and loved it and remembered it. And she doesn't have that quick temper." For her and four others, the experimental deep-brain-stimulation device restored, to different degrees, the cognitive abilities they had lost to brain injuries years before. The new technique, developed by Stanford Medicine researchers and collaborators from other institutions, is the first to show promise against the long-lasting impairments from moderate to severe traumatic brain injuries.

    Nicholas Schiff, Thalamic deep brain stimulation in traumatic brain injury: a phase 1, randomized feasibility study, Nature Medicine (2023). DOI: 10.1038/s41591-023-02638-4www.nature.com/articles/s41591-023-02638-4