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

    Faster and Cheaper Ethanol-to-Jet-Fuel

  • Dr. Krishna Kumari Challa

    'Charging room' system powers lights, phones, laptops without wires

    In a move that could one day free the world's countertops from their snarl of charging cords, researchers have developed a system to safely deliver electricity over the air, potentially turning entire buildings into wireless charging zones.

    Detailed in a new study published in Nature Electronics, the technology can deliver 50 watts of power using magnetic fields. In addition to untethering phones and laptops, the technology could also power implanted medical devices and open new possibilities for mobile robotics in homes and manufacturing facilities. The team is also working on implementing the system in spaces that are smaller than room-size, for example a toolbox that charges tools placed inside it.

    You could put a computer in anything without ever having to worry about charging or plugging in. There are a lot of clinical applications as well; today's heart implants, for example, require a wire that runs from the pump through the body to an external power supply. This could eliminate that, reducing the risk of infection and improving patients' quality of life.

    The system is a major improvement over previous attempts at wireless charging systems, which used potentially harmful microwave radiation or required devices to be placed on dedicated charging pads, the researchers say. Instead, it uses a conductive surface on room walls and a conductive pole to generate magnetic fields.

    Devices harness the magnetic field with wire coils, which can be integrated into electronics like cell phones. The researchers say the system could easily be scaled up to larger structures like factories or warehouses while still meeting existing safety guidelines for exposure to electromagnetic fields.

    Sasatani, T. et al, Room-scale magnetoquasistatic wireless power transfer using a cavity-based multimode resonator. Nat Electron (2021). doi.org/10.1038/s41928-021-00636-3

    https://techxplore.com/news/2021-08-room-powers-laptops-wires.html?...

  • Dr. Krishna Kumari Challa

    Synthetic biology enables microbes to build muscle

    Would you wear clothing made of muscle fibers? Use them to tie your shoes or even wear them as a belt? It may sound a bit odd, but if those fibers could endure more energy before breaking than cotton, silk, nylon, or even Kevlar, then why not? And this muscle could be produced without harming a single animal.

    Researchers have developed a synthetic chemistry approach to polymerize proteins inside of engineered microbes. This enabled the microbes to produce the high molecular weight muscle protein, titin, which was then spun into fibers.

    Their research was published Monday, August 30 in the journal Nature Communications.

    Microbial production of megadalton titin yields fibers with advantageous mechanical properties, Nature Communications (2021). DOI: 10.1038/s41467-021-25360-6

    https://phys.org/news/2021-08-synthetic-biology-enables-microbes-mu...

  • Dr. Krishna Kumari Challa

    Female octopuses observed throwing stuff at males harassing them

    A team of researchers has found that female octopuses sometimes throw silt at males who are attempting to mate with them. The group has written a paper describing their observations and has posted it on the bioRxiv preprint server.

    Earlier researchers recorded instances of octopuses throwing things at other octopuses. At the time, it was not clear if the other octopuses were being intentionally targeted or if it was accidental.

    In making more recordings and studying them carefully, the researchers were able to see that the female octopuses engaged in multiple types of object-throwing. In most instances, throwing material such as silt or even shells was simply a means of moving material that was in the way or when building a nest. Less often, they saw what were clearly attempts by females to hurl material at a nearby male—usually, one trying to mate with her.

    The researchers found that the hurling was done by grabbing material such as rocks, silt or shells and holding them under the body. Then the material was placed over a siphon that the creature uses for pushing out a jet of water very quickly. Doing so propelled the material ahead of a jet of water, sometimes as far as several body lengths.

    In studying the tape, the researchers found multiple instances of females targeting males. And the males duck half of the time!

    Peter Godfrey-Smith et al, In the Line of Fire: Debris Throwing by Wild Octopuses, biorxiv (2021). DOI: 10.1101/2021.08.18.456805

    https://phys.org/news/2021-08-female-octopuses-males.html?utm_sourc...

    OctopusesThrowing

  • Dr. Krishna Kumari Challa

    Research Finally Reveals Ancient Universal Equation for the Shape of an Egg

    Researchers have discovered the universal mathematical formula that can describe any bird’s egg existing in nature, a feat which has been unsuccessful until now.

    Egg-shape has long attracted the attention of mathematicians, engineers, and biologists from an analytical point of view. The shape has been highly regarded for its evolution as large enough to incubate an embryo, small enough to exit the body in the most efficient way, not roll away once laid, is structurally sound enough to bear weight and be the beginning of life for 10,500 species that have survived since the dinosaurs. The egg has been called the “perfect shape.”

    Analysis of all egg shapes used four geometric figures: sphere, ellipsoid, ovoid, and pyriform (conical), with a mathematical formula for the pyriform yet to be derived.

    To rectify this, researchers introduced an additional function into the ovoid formula, developing a mathematical model to fit a completely novel geometric shape characterized as the last stage in the evolution of the sphere-ellipsoid, which it is applicable to any egg geometry.

    This new universal mathematical formula for egg shape is based on four parameters: egg length, maximum breadth, shift of the vertical axis, and the diameter at one quarter of the egg length.

    This long sought-for universal formula is a significant step in understanding not only the egg shape itself, but also how and why it evolved, thus making widespread biological and technological applications possible.

    Mathematical descriptions of all basic egg shapes have already found applications in food research, mechanical engineering, agriculture, biosciences, architecture, and aeronautics. As an example, this formula can be applied to engineering construction of thin walled vessels of an egg shape, which should be stronger than typical spherical ones.

    “Egg and math: introducing a universal formula for egg shape” by Valeriy G. Narushin, Michael N. Romanov and Darren K. Griffin, 23 August 2021, Annals of the New York Academy of Sciences.
    DOI: 10.1111/nyas.14680

    https://scitechdaily.com/the-perfect-shape-research-finally-reveals...

  • Dr. Krishna Kumari Challa

    Making 1 Simple Substitution For Table Salt Could Save Millions of Lives, Study Shows

    Effect of Salt Substitution on Cardiovascular Events and Death

    too much salt is bad for you. More specifically, too much sodium is bad for you, and sodium is one of the two primary elements that make up salt (aka the chemical compound sodium chloride).

    At the same time, other studies have plotted the health impacts of insufficient potassium in people's diets, which also has a negative effect on blood pressure.

    As it happens, one product – commonly available in many supermarkets – can mitigate both these problems at the same time: salt substitutes that are designed to taste just like salt, but feature reduced levels of sodium and added amounts of potassium.

    Despite the promise of salt substitutes, however, there's been a lack of large clinical trials measuring their impact on stroke, heart disease, and death, so questions remain about how effective they are.

    Now, a giant study conducted in China seems to suggest pretty much everybody would benefit from making the switch.

    https://www.nejm.org/doi/10.1056/NEJMoa2105675

    https://www.sciencealert.com/making-1-simple-substitution-for-table...

    **

  • Dr. Krishna Kumari Challa

    Genes can respond to coded information in signals—or filter them out entirely

    New research demonstrates that genes are capable of identifying and responding to coded information in light signals, as well as filtering out some signals entirely. The study shows how a single mechanism can trigger different behaviours from the same gene—and has applications in the biotechnology sector.

    The fundamental idea here is that you can encode information in the dynamics of a signal that a gene is receiving. So, rather than a signal simply being present or absent, the way in which the signal is being presented matters.

    For this study, researchers modified a yeast cell so that it has a gene that produces fluorescent proteins when the cell is exposed to blue light.

    Here's how that works. A region of the gene called the promoter is responsible for controlling the gene's activity. In the modified yeast cells, a specific protein binds to the promoter region of the gene. When researchers shine blue light on that protein, it becomes receptive to a second protein. When the second protein binds to the first protein, the gene becomes active. And that's easy to detect, since the activated gene produces proteins that glow in the dark.

    The researchers then exposed these yeast cells to 119 different light patterns. Each light pattern differed in terms of the intensity of the light, how long each pulse of light was, and how frequently the pulses occurred. The researchers then mapped out the amount of fluorescent protein that the cells produced in response to each light pattern.

    People talk about genes being turned on or off, but it's less like a light switch and more like a dimmer switch—a gene can be activated a little bit, a lot, or anywhere in between. If a given light pattern led to the production of a lot of fluorescent protein, that means the light pattern made the gene very active. If the light pattern led to the production of just a little fluorescent protein, that means the pattern only triggered mild activity of the gene.

    The researchers found that different light patterns can produce very different outcomes in terms of gene activity, that all three light pattern variables—intensity of the light, frequency of the light pulses, and how long each pulse lasted—could influence gene activity, but found that controlling the frequency of light pulses gave them the most precise control over gene activity.

    Mapping the Dynamic Transfer Functions of Eukaryotic Gene Regulation, Cell Systems (2021).

    1. Jessica B. Lee et al. Mapping the dynamic transfer functions of eukaryotic gene regulation. Cell Systems, 2021 DOI: 10.1016/j.cels.2021.08.003

    https://phys.org/news/2021-08-genes-coded-signalsor-filter.html?utm...

  • Dr. Krishna Kumari Challa

    High virus count in the lungs drives COVID-19 deaths

    A buildup of coronavirus in the lungs is likely behind the steep mortality rates seen in the pandemic, a new study finds. The results contrast with previous suspicions that simultaneous infections, such as bacterial pneumonia or overreaction of the body's immune defense system, played major roles in heightened risk of death, the investigators say.

    the new study showed that people who died of COVID-19 had on average 10 times the amount of virus, or viral load, in their lower airways as did severely ill patients who survived their illness. Meanwhile, the investigators found no evidence implicating a secondary bacterial infection as the cause of the deaths, although they cautioned that this may be due to the frequent course of antibiotics given to critically ill patients.

    These findings suggest that the body's failure to cope with the large numbers of virus infecting the lungs is largely responsible for COVID-19 deaths in the pandemic.

    Despite previous concerns that the virus may prompt the immune system to attack the body's own lung tissue and lead to dangerous levels of inflammation, the investigators found no evidence that this was a major contributor to COVID-19 deaths in the group studied. In fact,  this study notes that the strength of the immune response appeared proportionate to the amount of virus in the lungs.

    The new study, publishing online Aug. 31 in the journal Nature Microbiology, was designed to clarify the role of secondary infections, viral load, and immune cell populations in COVID-19 mortality.

    1. Imran Sulaiman, Matthew Chung, Luis Angel, Jun-Chieh J. Tsay, Benjamin G. Wu, Stephen T. Yeung, Kelsey Krolikowski, Yonghua Li, Ralf Duerr, Rosemary Schluger, Sara A. Thannickal, Akiko Koide, Samaan Rafeq, Clea Barnett, Radu Postelnicu, Chang Wang, Stephanie Banakis, Lizzette Pérez-Pérez, Guomiao Shen, George Jour, Peter Meyn, Joseph Carpenito, Xiuxiu Liu, Kun Ji, Destiny Collazo, Anthony Labarbiera, Nancy Amoroso, Shari Brosnahan, Vikramjit Mukherjee, David Kaufman, Jan Bakker, Anthony Lubinsky, Deepak Pradhan, Daniel H. Sterman, Michael Weiden, Adriana Heguy, Laura Evans, Timothy M. Uyeki, Jose C. Clemente, Emmie de Wit, Ann Marie Schmidt, Bo Shopsin, Ludovic Desvignes, Chan Wang, Huilin Li, Bin Zhang, Christian V. Forst, Shohei Koide, Kenneth A. Stapleford, Kamal M. Khanna, Elodie Ghedin, Leopoldo N. Segal. Microbial signatures in the lower airways of mechanically ventilated COVID-19 patients associated with poor clinical outcome. Nature Microbiology, 2021; DOI: 10.1038/s41564-021-00961-5

    https://medicalxpress.com/news/2021-08-high-virus-lungs-covid-death...

  • Dr. Krishna Kumari Challa

    The right mixture of salts to get life started

    In modern organisms, the hereditary material DNA encodes the instructions for the synthesis of proteins—the versatile nanomachines that enable modern cells to function and replicate. But how was this functional linkage between DNA and proteins established? According to the "RNA world" hypothesis, primordial living systems were based on self-replicating RNA molecules. Chemically speaking, RNA is closely related to DNA. However, in addition to storing information, RNA can fold into complex structures that have catalytic activity, similar to the protein nanomachines that catalyze chemical reactions in cells. These properties suggest that RNA molecules should be capable of catalyzing the replication of other RNA strands, and initiating self-sustaining evolutionary processes. Hence, RNA is of particular interest in the context of the origin of life as a promising candidate for the first functional biopolymer.

    --

    New options for sustainable antibiotic therapy

    Public health is coming under increasing pressure worldwide due to the antibiotic crisis: the rapid increase in resistance of bacterial pathogens could mean that in the near future bacterial infections that are usually harmless will be difficult or impossible to treat. The spread of antibiotic resistance is based on the ability of pathogens to adapt quickly to the drugs. In principle, evolutionary theory assumes that this adaptation is more difficult when environmental conditions change rapidly. Sequential antibiotic therapy, which involves switching between different antibiotics in a short time, could therefore lead to a reduction in the spread of resistance. This therapeutic approach is usually not considered in medical treatment and is also hardly investigated in basic research—despite the possible long-term benefits.

  • Dr. Krishna Kumari Challa

    Researchers take step toward using cellular motion to help wound healing

    With a technique that overcomes cells' innate social behaviors, researchers have taken an important step in directing skin cells to migrate en masse to close wounds—"literally making skin crawl".

    In a new study, the researchers overcame the inertia typical of mature skin tissue by breaking the molecular connections between cells, applying an electrical field to direct their migration and then rebuilding the connections. This novel approach improves the controllability of tissues and may one day help optimize wound healing through electrical stimulation.

    Research showed that cells in the body can sense and follow an electric field, a process called electrotaxis. Electric fields generated in the body promote healing by directing cells to move toward the wound and are also vital for growth and development.

    Despite promising clinical evidence from decades of use in patients, scientists have yet to work out how cells detect and respond to electric fields or how electrical stimulation can best be applied therapeutically. "It's kind of a black box

     Gawoon Shim et al, Overriding native cell coordination enhances external programming of collective cell migration, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2101352118

    part1

  • Dr. Krishna Kumari Challa

    In their previous work, Cohen's group used electric fields to program thousands of individual cells to move in circles and around corners. Their new study used a model of more mature skin—a single layer of mouse skin cells all latched together—which is harder to control. Instead of moving with the speed and precision of a marching band in response to an electric current, the mature skin cells inched along like a crowd of people holding hands with their neighbors.

    The mature skin also posed another problem: Once the leading edge of cells advanced, it would peel away from the petri dish and die. "If you apply a command that differs from what the cells naturally 'want' to do, you get a tug-of-war. The result was the tissues ripped themselves apart.

    Cohen and Shim suspected that the "handshakes" between cells prevented the tissue from fluidly following the electrical commands. These handshakes are proteins called cadherins that anchor neighboring cells together. They make tissues cohesive so they can move together but can also create traffic jams when cells don't have space to move.

     Gawoon Shim et al, Overriding native cell coordination enhances external programming of collective cell migration, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2101352118

    https://phys.org/news/2021-08-cellular-motion-wound.html?utm_source...

    part 2

  • Dr. Krishna Kumari Challa

    Cadherins need calcium ions to complete their connections, so Shim grew the cells with different amounts of calcium and measured their response to electrical stimulation. She saw that the less calcium the cells had, the more fluid they became and the quicker they moved. "It goes really fast.

    Calcium has many effects on living tissues, however, so Shim had to confirm that the handshakes were to blame for the slow movement. She grew cells with an antibody that attaches to cadherins. With blocked handshakes, these cells moved more quickly.

    After working out the ground rules of cell adhesiveness, the researchers developed a solution to their sticky cell problem. Shim grew a layer of skin cells in a high calcium solution so they made their normal connections. Then she treated the cells with a chemical that grabs up calcium ions to break up the cellular handshakes. When Shim lowered the calcium level and applied the electric field, the cells moved on command. Finally, she restored the high calcium level to reinstate the handshakes, resulting in a healthy and cohesive layer of skin cells.

    To demonstrate that this approach has the potential to accelerate healing, Shim performed the above experiment using an electrobioreactor developed in the Cohen lab that mimics the closing of a wound. Unlike other models of electrotaxis where the electric field moves cells in one direction, their new system exposes cells to an electric field focused on the center of the injury. Shim showed that the stimulated tissues successfully came together while the unstimulated ones remained largely separate. Cohen's group described their electrobioreactor in a new paper in Biosensors and Bioelectronics.

    part3

  • Dr. Krishna Kumari Challa

    Model of SARS-CoV-2 dynamics reveals opportunity to prevent COVID-19 transmission

    Scientists have simulated the transition of the SARS-CoV-2 spike protein structure from when it recognizes the host cell to when it gains entry, according to a study published today in eLife.

    The research shows that a structure enabled by sugar molecules on the spike protein could be essential for cell entry and that disrupting this structure could be a strategy to halt virus transmission.
    An essential aspect of SARS-CoV-2's lifecycle is its ability to attach to host cells and transfer its genetic material. It achieves this through its spike protein, which is made up of three separate components—a transmembrane bundle that anchors the spike to the virus, and two S subunits (S1 and S2) on the exterior of the virus. To infect a human cell, the S1 subunit binds to a molecule on the surface of human cells called ACE2, and the S2 subunit detaches and fuses the viral and human cell membranes. Although this process is known, the exact order in which it occurs is as yet undiscovered. Yet, understanding the microsecond-scale and atomic-level movements of these protein structures could reveal potential targets for COVID-19 treatment.
    Most of the current SARS-CoV-2 treatments and vaccines have focused on the ACE2 recognition step of virus invasion, but an alternative strategy is to target the structural change that allows the virus to fuse with the human host cell.
    But probing these intermediate, transient structures experimentally is extremely difficult, and so researchers now  used a computer simulation sufficiently simplified to investigate this large system but that maintains sufficient physical details to capture the dynamics of the S2 subunit as it transitions between pre-fusion and post-fusion shapes.
    part 1
  • Dr. Krishna Kumari Challa

    The team was particularly interested in the role of sugar molecules on the spike protein, which are called glycans. To see whether the number, type and position of glycans play a role in the membrane fusion stage of viral cell entry by mediating these intermediate spike formations, they performed thousands of simulations using an all-atom structure-based model. Such models allow prediction of the trajectory of atoms over time, taking into account steric forces—that is, how neighboring atoms affect the movement of others.

    The simulations revealed that glycans form a "cage" that traps the "head" of the S2 subunit, causing it to pause in an intermediate form between when it detaches from the S1 subunit and when the viral and cell membranes are fused. When the glycans were not there, the S2 subunit spent much less time in this conformation.

    The simulations also suggest that holding the S2 head in a particular position helps the S2 subunit recruit human host cells and fuse with their membranes, by allowing the extension of short proteins called fusion peptides from the virus. Indeed, glycosylation of S2 significantly increased the likelihood that a fusion peptide would extend to the host cell membrane, whereas when glycans were absent, there was only a marginal possibility that this would occur.

     simulations indicate that glycans can induce a pause during the spike protein transition. This provides a critical opportunity for the fusion peptides to capture the host cell.

    In the absence of glycans, the viral particle would likely fail to enter the host. Our study reveals how sugars can control infectivity, and it provides a foundation for experimentally investigating factors that influence the dynamics of this pervasive and deadly pathogen.

    Esteban Dodero-Rojas et al, Sterically confined rearrangements of SARS-CoV-2 Spike protein control cell invasion, eLife (2021). DOI: 10.7554/eLife.70362

    https://phys.org/news/2021-08-sars-cov-dynamics-reveals-opportunity...

    part 2 **

  • Dr. Krishna Kumari Challa

     Winners from the Wellcome Photography Prize 2021: 

    Fighting Infections

    The Time of Coronavirus by Aly Song. Volunteers from the Blue Sky Rescue Team, the largest humanitarian NGO in China, are pictured disinfecting the Qintai Grand Theatre in Wuhan, near to where the COVID-19 pandemic began © Aly Song/Wellcome Photography Prize 2021

  • Dr. Krishna Kumari Challa

    Scientists  discover a rare, aggressive form of Alzheimer's that begins in the early 40s

    A newly discovered gene mutation linked to early onset Alzheimer's disease has been discovered by an international team of scientists, who traced the DNA flaw through multiple members of a single family.

    Alzheimer's has long been known as a mind-robbing disease that that wipes out memories and destroys one's sense of self. Most cases of arise sporadically, emerging after age of 65—transmuting one's golden years into a nightmare marked by an incurable brain disease.

    Aside from Alzheimer's dementia that begins sporadically in old age, are insidious familial forms that begin years to decades earlier. Early onset refers Alzheimer's that begins before age 65.

    Now, an international team of scientists—led by neurobiologists in Sweden—have identified an extraordinarily rare form of the disease that so far has been found only in one family. This form of Alzheimer's is aggressive, rapid and steals its victims' most productive years along their cognitive functions.

    Researchers in Sweden have named this form of Alzheimer's—the Uppsala APP deletion—after the family that's endowed with this notorious DNA miscue. It invariably causes descent into dementia at a young age.

    Affected individuals have an age at symptom onset  in their early forties, and suffer from a rapidly progressing disease course.

    Researchers found that the mutation accelerates the formation of brain-damaging protein plaques, known as amyloid beta, or more simply as Aβ. The gooey plaques destroy neurons and, as a result, annihilate the executive functions of the brain itself. Neuroscientists basically define executive functions as working memory, mental flexibility and self control.

    María Pagnon de la Vega et al, The Uppsala APP deletion causes early onset autosomal dominant Alzheimer's disease by altering APP processing and increasing amyloid β fibril formation, Science Translational Medicine (2021). DOI: 10.1126/scitranslmed.abc6184

    https://medicalxpress.com/news/2021-09-scientists-sweden-rare-aggre...

  • Dr. Krishna Kumari Challa

    Do genetics control who our friends are? It seems so with mice

    Have you ever met someone you instantly liked, or at other times, someone who you knew immediately that you did not want to be friends with, although you did not know why?

    Some people speculated that "unconscious" part of the brain enables us to process information spontaneously, when, for example, meeting someone for the first time, interviewing someone for a job, or faced with making a decision quickly under stress.

    Now, a new study from the University of Maryland School of Medicine (UMSOM) suggests that there may be a biological basis behind this instantaneous compatibility reaction. A team of researchers showed that variations of an enzyme found in a part of the brain that regulates mood and motivation seems to control which mice want to socially interact with other mice—with the genetically similar mice preferring each other.

    These findings may indicate that similar factors could contribute to the social choices people make. Understanding what factors drive these social preferences may help us to better recognize what goes awry in diseases associated with social withdrawal, such as schizophrenia or autism, so that better therapies can be developed.

    The study was published on July 28 in Molecular Psychiatry, a Nature publication.

    But, let us wait till these results are reproduced several times before coming to a conclusion.

     Abigail J. Smith et al, A genetic basis for friendship? Homophily for membrane-associated PDE11A-cAMP-CREB signaling in CA1 of hippocampus dictates mutual social preference in male and female mice, Molecular Psychiatry (2021). DOI: 10.1038/s41380-021-01237-4

    https://medicalxpress.com/news/2021-09-genetics-friends-mice.html?u...

  • Dr. Krishna Kumari Challa

    Hidden bacterial hairs power nature's 'electric grid'

    A hair-like protein hidden inside bacteria serves as a sort of on-off switch for nature's "electric grid," a global web of bacteria-generated nanowires that permeates all oxygen-less soil and deep ocean beds,  researchers report in the journal Nature.

    The ground beneath our feet, the entire globe, is electrically wired. These previously hidden bacterial hairs are the molecular switch controlling the release of nanowires that make up nature's electrical grid.

    Almost all living things breathe oxygen to get rid of excess electrons when converting nutrients into energy. Without access to oxygen, however, soil bacteria living deep under oceans or buried underground over billions of years have developed a way to respire by "breathing minerals," like snorkeling, through tiny protein filaments called nanowires.

    Scientists had thought that the nanowires are made up of a protein called "pili" ("hair" in Latin) that many bacteria show on their surface. This work has reveal that this pili structure is made up of two proteins And instead of serving as nanowires themselves, pili remain hidden inside the bacteria and act like pistons, thrusting the nanowires into the environment. Previously nobody had suspected such a structure.

    Just how these soil bacteria use nanowires to exhale electricity, however, has remained a mystery. Now that mystery has been solved.

    Understanding how bacteria create nanowires will allow scientists to tailor bacteria to perform a host of functions—from combatting pathogenic infections or biohazard waste to creating living electrical circuits, the authors say. It will also assist scientists seeking to use bacteria to generate electricity, create biofuels, and even develop self-repairing electronics.

    Structure of Geobacter pili reveals secretory rather than nanowire behaviour, Nature (2021). DOI: 10.1038/s41586-021-03857-w , www.nature.com/articles/s41586-021-03857-w

    https://phys.org/news/2021-09-hidden-bacterial-hairs-power-nature.h...

  • Dr. Krishna Kumari Challa

    Ultrasonic social distancing

    Social distancing has been a critical component of the world's response to the COVID-19 pandemic. The idea being that keeping physical apart from other people will reduce the risk of a person spreading the respiratory virus to someone else. It is just one component of our response, which also includes wearing face coverings, frequent hand sanitisation, and obtaining a vaccine against the virus.

    New research in the International Journal of Sensor Networks discusses the potential of ultrasonic sensors to help people keep a safe distance from others when social distancing is deemed necessary in a pandemic situation.

    Mohit Ghai and Ruchi Gupta of the Department of Electrical and Electronics Engineering at ADGITM, IP University in Delhi, India, describe a small, portable sensor-alarm device based on an Arduino system. Arduino is an open-source hardware and software system that can be used to quickly build single-board microcontrollers and microcontroller kits with a variety of inexpensive applications. There is scope to add Wi-Fi capability and other networking functionality to a device too.

    The team's Arduino device has an ultrasonic sensor that continuously probes the space around a person and is triggered when another person enters one's personal space within a pre-determined threshold distance set according to social distancing rules. The system is not dissimilar to the parking sensors with which many vehicles are fitted and so could give a timely indication to the user that they have moved too close to another person unwittingly or alert them when another person moves nearer to them in a shopping queue or other setting, for instance.

    Given how often people misjudge distances between themselves and others especially in busy environments, a portable alarm system of this sort could be a boon to those hoping to ensure social distancing is maintained to help reduce the risk of spreading infection.

    Mohit Ghai et al, Ultrasonic sensor based social distancing device, International Journal of Sensor Networks (2021). DOI: 10.1504/IJSNET.2021.117227

    https://techxplore.com/news/2021-09-ultrasonic-social-distancing.ht...

  • Dr. Krishna Kumari Challa

    Scientific breakthrough in the battle against cancer: First 3D printing of glioblastoma cancer tumor

  • Dr. Krishna Kumari Challa

    Biologists Just Got Closer to The DNA Secrets That Stop Species From Interbreeding

    We think of DNA as the vitally important molecules that carry genetic instructions for most living things, including ourselves. But not all DNA actually codes proteins; now, we're finding more and more functions involving the non-coding DNA scientists used to think of as 'junk'.

    A new study suggests that satellite DNA – a type of non-coding DNA arranged in long, repetitive, apparently nonsensical strings of genetic material – may be the reason why different species can't successfully breed with each other.

    It appears that satellite DNA plays an essential role in keeping all of a cell's individual chromosomes together in a single nucleus, through the work of cellular proteins.

    According to biologists Madhav Jagannathan and Yukiko Yamashita who authored the new study, that important role is managed differently in each species, leading to genetic incompatibility. The clash of the different strategies between species may be what causes chromosomes to scatter outside of the nucleus, at least in part, preventing reproduction.

    "We propose a unifying framework that explains how the widely observed satellite DNA divergence between closely related species can cause reproductive isolation," they write in their paper.

    This "satellite DNA divergence" has been well established in previous research, leading to suspicions about its role in speciation. In the case of the chimpanzee genome and the human genome, for example, the protein-coding DNA is almost identical, while the 'junk' DNA is almost entirely different.

    https://academic.oup.com/mbe/advance-article/doi/10.1093/molbev/msa...

    https://www.sciencealert.com/junk-dna-could-be-why-different-specie...

  • Dr. Krishna Kumari Challa

    Study explores the influence of the X-chromosome on brain anatomy

    Past neuroscience research suggests that common differences in people's genetic profiles can explain a significant proportion of variations in people's brain anatomy. In more specific terms, they found that neuroanatomical variation is partly explained by genetic variation.

    Scientists have hypothesized that the X-chromosome has a particularly crucial influence on the brain, as it is known to be associated with the expression of many genes. In addition, several types of intellectual disabilities have been found to be related with mutations of genes on the X chromosome.

    All existing studies investigating the role of genetics on brain anatomy excluded the X-chromosome, which accounts for about 5% of our genomes. it would be important to address this gap because—beyond the basic need to complete the missing analysis—there were lot of existing hints that the X-chromosome might actually have a special capacity to explain variation in brain anatomy.

    So  if a common genetic variation explains 30% of variation in total brain volume, then a chromosome which represents 10% of the genome would explain 3% of variation in total brain volume.

    The X-chromosome consists of approximately 5% of the total genome. Taking this into consideration, researchers calculated the proportion of anatomical variation that could be explained by the X-chromosome. They found that given its known size and the percentage of the human genome it represents, the proportion they calculated differed significantly from the expected proportion.

    The main take-aways from our studies are that the X-chromosome does indeed 'punch above its weight' in its capacity to explain differences in brain anatomy and that this phenomenon seems to be concentrated in particular brain systems important for complex thinking, decision making and action.

    In terms of practical implications— this finding tells us that we really do need to put an end to exclusion of the X-chromosome from genetic analyses of the brain and related traits such as cognition and behavior.

    The findings gathered by this team of researchers significantly enrich the current understanding of the X-chromosome's role in human neurodevelopment.

    X-chromosome influences on neuroanatomical variation in humans. Nature Neuroscience(2021). DOI: 10.1038/s41593-021-00890-w

    https://medicalxpress.com/news/2021-09-explores-x-chromosome-brain-...

    **

  • Dr. Krishna Kumari Challa

    A gecko-inspired robot's crash-landing correction

  • Dr. Krishna Kumari Challa

    Birds and mammals evolve faster if their home is rising

    The rise and fall of Earth's land surface over the last three million years shaped the evolution of birds and mammals, a new study has found, with new species evolving at higher rates where the land has risen most.

    Researchers at the University of Cambridge have combined reconstructions of the Earth's changing surface elevations over the past three million years with data on climate change over this timeframe, and with bird and mammal species' locations. Their results reveal how species evolved into new ones as land elevation changed—and disentangle the effects of elevation from the effects of climate.

    The study found that the effect of elevation increase is greater 

    than that of historical climate change, and of present-day elevation and temperature, in driving the formation of new species – 'or speciation'.

    In contrast to areas where land elevation is increasing, elevation loss was not found to be an important predictor of where speciation happens. Instead, present-day temperature is a better indicator of speciation in these areas.

    The results are published today in the journal Nature Ecology and Evolution.

     Global topographic uplift has elevated speciation in mammals and birds over the last 3 million years, Nature Ecology and Evolution (2021). DOI: 10.1038/s41559-021-01545-6 , www.nature.com/articles/s41559-021-01545-6

    https://phys.org/news/2021-09-birds-mammals-evolve-faster-home.html...

  • Dr. Krishna Kumari Challa

    Nano 'camera' made using molecular glue allows real-time monitoring of chemical reactions

    Researchers have made a tiny camera, held together with 'molecular glue' that allows them to observe chemical reactions in real time.

    The device, made by a team from the University of Cambridge, combines tiny semiconductor nanocrystals called quantum dots and gold nanoparticles using molecular glue called cucurbituril (CB). When added to water with the molecule to be studied, the components self-assemble in seconds into a stable, powerful tool that allows the real-time monitoring of chemical reactions.

    The camera harvests light within the semiconductors, inducing electron transfer processes like those that occur in photosynthesis, which can be monitored using incorporated gold nanoparticle sensors and spectroscopic techniques. They were able to use the camera to observe chemical species which had been previously theorized but not directly observed.

    The platform could be used to study a wide range of molecules for a variety of potential applications, such as the improvement of photocatalysis and photovoltaics for renewable energy. The results are reported in the journal Nature Nanotechnology.

    Földes, T. et al, Nanoparticle surfactants for kinetically arrested photoactive assemblies to track light-induced electron transfer, Nat. Nanotechnol. (2021). DOI: 10.1038/s41565-021-00949-6 , www.nature.com/articles/s41565-021-00949-6

    https://phys.org/news/2021-09-nano-camera-molecular-real-time-chemi...

  • Dr. Krishna Kumari Challa

    Decaying forest wood releases 10.9 billion tons of carbon yearly, which will increase with climate change

    If you've wandered through a forest, you've probably dodged dead, rotting branches or stumps scattered on the ground. This is "deadwood," and it plays several vital roles in forest ecosystems.

    It provides habitat for small mammals, birds, amphibians and insects. And as deadwood decomposes it contributes to the ecosystem's cycle of nutrients, which is important for plant growth.

    But there's another important role we have little understanding of on a global scale: the carbon deadwood releases as it decomposes, with part of it going into the soil and part into the atmosphere. Insects, such as termites and wood borers, can accelerate this process.

    The world's deadwood currently stores 73 billion tons of carbon. Our new research in Nature has, for the first time, calculated that 10.9 billion tons of this (around 15%) is released into the atmosphere and soil each year—a little more than the world's emissions from burning fossil fuels.

    But this amount can change depending on insect activity, and will likely increase under climate change. It's vital deadwood is considered explicitly in all future climate change projections.

    Sebastian Seibold et al, The contribution of insects to global forest deadwood decomposition, Nature (2021). DOI: 10.1038/s41586-021-03740-8

    https://phys.org/news/2021-09-forest-wood-billion-tons-carbon.html?...

    **

  • Dr. Krishna Kumari Challa

    How harmful is methane?

    Methane contributes to global warming; it is therefore a greenhouse gas. Of all the methane produced in some developed countries, 70% comes from livestock farming. A substantial percentage. But how harmful is it? Because, unlike other greenhouse gasses, methane breaks down relatively quickly in the atmosphere. 

    Greenhouse gasses are important. They form a blanket around the earth. Without greenhouse gasses, it would be unbearably cold on earth. The problem with the greenhouses gasses is that we too much of them. The blanket becomes so thick, that the earth's temperature rises. This causes periods of drought and in other places too much precipitation, the polar caps melt, and so on.

    there are three greenhouse gasses: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Roughly speaking, you can say that all three are created during the breakdown or combustion of organic substances. CO2 (and NOx) are mainly created through the combustion of diesel, lignite or gasoline. Not only in transport and traffic, but also in production processes. From the concrete in your house to the staples in your furniture, almost everything in our lives produces CO2 during its production.

    Methane is released during the breakdown of organic substances. For example, in the gastrointestinal tract of animals. Ruminants (cows, goats, sheep) in particular produce a lot of methane. Methane is also 34 times more powerful than carbon dioxide. So, the earth warms up extra fast when there is more methane in the atmosphere. N2O is created in processes where nitrogen compounds play a role: in manure storage and manure application."

    part 1

  • Dr. Krishna Kumari Challa

    CO2 stays in the atmosphere for a very, very long time. Many thousands of years. So that greenhouse gas accumulates, and the 'blanket' around the earth thickens. The unique thing about methane is that it halves in the atmosphere in just over 8 years. The other half becomes CO2. So if you emit 100 kilos of methane today, in 8.5 years there will be 50 kilos left, and after another 8.5 years only 25 kilos, and so on," Vellinga explains. "That CO2 has gone through what is known as the short carbon cycle: it was converted by grass, corn, etc. into plant material, which the cow converts back into CO2 and CH4. And that CH4 becomes CO2 again pretty quickly. Nothing to worry about, you might say."

    "But be careful not to make the problem too small. Before you know it, it seems as if there is nothing wrong with methane. On the contrary. As long as methane is in the atmosphere, it contributes very strongly to warming. Over the lifetime of methane, this is as much as 80 to 100 times more than CO2.

    But the advantage is that it disappears quickly. Reducing methane emissions can cause the concentration of methane in the atmosphere to drop and therefore even reduce the greenhouse effect. When reducing CO2, the current greenhouse effect remains the same and only does not increase. So reducing methane is more effective than reducing CO2. But it has to be done both ways."

    https://phys.org/news/2021-09-fact-methane.html?utm_source=nwletter...

    Part 2

    **

  • Dr. Krishna Kumari Challa

    How Do Ants Tunnel So Well?

  • Dr. Krishna Kumari Challa

    Drug cocktail reduces aging-associated disc degeneration

    Chronic back pain affects  millions of  adults in the world. Degeneration of the discs that cushion and support vertebrae, a common occurrence of aging, is a major contributor to low back pain. Although a widespread condition, few treatments are available.

    With age, every tissue in the body accumulates senescent cells. Senescent cells secrete destructive enzymes and inflammatory proteins that affect nearby healthy cells. Senolytic drugs remove these deteriorating cells, leaving room for new cells to replace them. The idea is that removing senescent cells from a tissue will improve the tissue's function.

    New research has shown  that treating mice with a drug cocktail that removes aging cells reduces disc degeneration. The findings, reported in Nature Communications on September 3rd, show how a novel approach to preventing age-related disc degeneration may pave the way for treating chronic back pain.

    The findings show that senolytic drugs—ones already approved for use in clinical trials—can mitigate disc degeneration that occurs with aging.

    Just because the drugs work in one tissue doesn't mean they will also work in another. Every tissue is different and should be treated differently.

    Young and middle-aged mice given the senolytic cocktail showed less disc degeneration and fewer senescent cells by the time they reached an advanced age compared to mice given a placebo.

    "Long-term treatment with senolytic drugs Dasatinib and Quercetin ameliorates age-dependent intervertebral disc degeneration in mice." Nature Communications (2021) , DOI: 10.1038/s41467-021-25453-2

    https://medicalxpress.com/news/2021-09-drug-cocktail-aging-associat...

  • Dr. Krishna Kumari Challa

    The first cells might have used temperature to divide

    A simple mechanism could underlie the growth and self-replication of protocells—putative ancestors of modern living cells—suggests a study publishing September 3 in Biophysical Journal. Protocells are vesicles bounded by a membrane bilayer and are potentially similar to the first unicellular common ancestor (FUCA). On the basis of relatively simple mathematical principles, the proposed model suggests that the main force driving protocell growth and reproduction is the temperature difference that occurs between the inside and outside of the cylindrical protocell as a result of inner chemical activity.

    The purpose of this study was to identify the main forces driving cell division. This is important because cancer is characterized by uncontrolled cell division. This is also important to understand the origin of life.

    The splitting of a cell to form two daughter cells requires the synchronization of numerous biochemical and mechanical processes involving cytoskeletal structures inside the cell. But in the history of life, such complex structures are a high-tech luxury and must have appeared much later than the ability to split. Protocells must have used a simple splitting mechanism to ensure their reproduction, before the appearance of genes, RNA, enzymes, and all the complex organelles present today, even in the most rudimentary forms of autonomous life.

    In the new study, researchers proposed a model based on the idea that the early forms of life were simple vesicles containing a particular network of chemical reactions—a precursor of modern cellular metabolism. The main hypothesis is that molecules composing the membrane bilayer are synthesized inside the protocell through globally exothermic, or energy-releasing, chemical reactions.

    The slow increase of the inner temperature forces the hottest molecules to move from the inner leaflet to the outer leaflet of the bilayer. This asymmetric movement makes the outer leaflet grow faster than the inner leaflet. This differential growth increases the mean curvature and amplifies any local shrinking of the protocell until it splits in two. The cut occurs near the hottest zone, around the middle.

    The scenario described can be viewed as the ancestor of mitosis. Having no biological archives as old as 4 billion years, we don't know exactly what FUCA contained, but it was probably a vesicle bounded by a lipid bilayer encapsulating some exothermic chemical reactions.

    Although purely theoretical, the model could be tested experimentally.

    Biophysical Journal, Attal and Schwartz: "Thermally driven fission of protocells" www.cell.com/biophysical-journ … 0006-3495(21)00686-X  , DOI: 10.1016/j.bpj.2021.08.020

    https://phys.org/news/2021-09-cells-temperature.html?utm_source=nwl...

    **

  • Dr. Krishna Kumari Challa

    Unified theory explains how materials transform from solids to liquids

    A new study unveils a unified mathematical expression that defines how soft-yet-rigid materials transition from a solid into a liquid flow when they exceed their specific stress threshold.

    This study has shown   that these physical states—solid and liquid—can exist together in the same material, and we can explain it using one mathematical expression.

    To develop this model, the team performed numerous studies that subjected a variety of different soft materials to stress while measuring the individual solidlike and liquidlike strain responses using a device called a rheometer.

    The researchers were able to observe a material's behavior and see a continuous transition between the solid and liquid states and were able to resolve two distinct behaviors that reflect energy dissipation via solid and fluid mechanisms.

    Krutarth Kamani et al, Unification of the Rheological Physics of Yield Stress Fluids, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.218002

    https://phys.org/news/2021-09-theory-materials-solids-liquids.html?...

  • Dr. Krishna Kumari Challa

    Fish eyes grown in a petri dish from embryonic stem cells

    A research team has demonstrated that complex retinal tissue can be cultured in a Petri dish from embryonic stem cells of bony fish. Until now, stem cells from mammals, including humans, have been used in organoid research. For the first time, researchers have demonstrated that stem cells from medaka and zebrafish can also form highly organized neural structures under controlled laboratory conditions. Among other things, the researchers expect to gain new insights into the basic mechanisms of retinal development.

    Organoids are bits of tissue that are grown from stem cells and resemble actual organs. They are used in basic research to gain new information on cell organization and organ development, to investigate the origin of disease, and to develop and test new medications. The major advantage of fish organoids is that they are highly reproducible, unlike organoids from mammalian stem cells. They develop reliably and very quickly and enable a direct comparison with living embryos that in fish grow outside of the womb.

    Researchers are  now able to manipulate the molecular and genetic mechanisms of retina  formation.

      Researchers used pluripotent stem cells  from medaka and zebrafish embryos. Such cells have not yet differentiated and can potentially develop into many different cell types. All the cells taken from a single embryo independently aggregated into one large retina within 24 hours. In a matter of a few days, it then formed layers of different cell types that are also found in the fish eye, including photoreceptor cells, bipolar cells, amacrine cells, and ganglion cells. The growth process proved to be incredibly efficient. Hundreds of small retina organoids could be generated within a day. The high throughput allowed the researchers to precisely isolate the conditions in which structures resembling a head with two eyes, including both brain and retina, are formed.

    Lucie Zilova et al, Fish primary embryonic pluripotent cells assemble into retinal tissue mirroring in vivo early eye development, eLife (2021). DOI: 10.7554/eLife.66998

    https://phys.org/news/2021-09-fish-eyes-grown-petri-dish.html?utm_s...

  • Dr. Krishna Kumari Challa

    Coronavirus epidemics first hit more than 21,000 years ago

    Sarbecoviruses have crossed into humans twice in the last decade, leading to the deadly SARS-CoV-1 outbreak in 2002-04 and the current COVID-19 pandemic, caused by the SARS-CoV-2 virus. A new Oxford University study, published today, shows that the most recent common ancestor of these viruses existed more than 21,000 years ago, nearly 30 times older than previous estimates.

    Despite having a very rapid rate of evolution over short timescales, to survive, viruses must remain highly adapted to their hosts—this imposes severe restrictions on their freedom to accumulate mutations without reducing their fitness. This causes the apparent rate of evolution of viruses to slow down over time. The new research, for the first time, successfully recreates the patterns of this observed rate decay in viruses.

    The study also demonstrates that while existing evolutionary models have often failed to measure the divergence between virus species over periods—from a few hundred to a few thousands of years—the evolutionary framework developed in this study will enable the reliable estimation of virus divergence across vast timescales, potentially over the entire course of animal and plant evolution.

    The new model enables us to not only reconstruct the evolutionary history of viruses related to SARS-CoV-2, but also a much wider range of RNA and DNA viruses during more remote periods in the past.

    Mahan Ghafari et al, A mechanistic evolutionary model explains the time-dependent pattern of substitution rates in viruses, Current Biology (2021). DOI: 10.1016/j.cub.2021.08.020

    https://phys.org/news/2021-09-coronavirus-epidemics-years.html?utm_...

  • Dr. Krishna Kumari Challa

    Hormones May Contribute to Asymmetrical Effects of Brain Injury


    Researchers studying rats claim to have found a novel connection between damage on one side of the brain and problems with the posture or movement of limbs on the opposite side of the body.

    Injury to one side of the brain can cause abnormalities in posture or movement on the opposite side of the body. These effects, which are sometimes seen in people who have suffered a stroke or head trauma, have typically been attributed to neural pathways that link the right side of the brain to spinal cord neurons controlling muscles on the left side of the body, and vice versa. 

    But in a new study on rats that had their spinal cords severed, researchers claim to have discovered another, parallel pathway that triggers opposite-side effects following brain injury and might instead operate via hormones circulating in the blood.

    If similar mechanisms operate in humans, it’s conceivable that drugs blocking receptors for particular hormones could help treat some of the physical effects of brain injury

    https://elifesciences.org/articles/65247

    https://www.the-scientist.com/news-opinion/hormones-may-contribute-...


  • Dr. Krishna Kumari Challa

    “Mystery Fever” Claims the Lives of Dozens of Indian Children

    So far, more than 50 people have died of a febrile illness, though the cause isn’t clear.

    In addition to the ongoing COVID-19 pandemic and an uptick of malaria cases across the country, an unknown disease has killed more than 50 people in the state of Uttar Pradesh, India in the last week; most were children. All of the patients tested negative for COVID-19, and India Today reports it is likely that scrub typhus is to blame, though other possibilities, such as dengue, have not been ruled out.

     The Hindustan Times reports, and monsoon season has brought a greater number of mosquito-borne illnesses. Now, many regions in the state are reporting illness and death due to a mystery fever.

    Water-logging, and lack of sanitation and hygiene are the reasons behind the disease spread. The patients, especially children, in hospitals are dying very quickly.

    According to multiple news outlets, the hundreds of people hospitalized by the illness have experienced fever, headaches, joint pain, nausea, rashes, and dehydration. A drop in platelet count has also been observed in many fatal cases. Though many of these symptoms can occur in severe dengue cases, The Hindustan Times and others report that the likely culprit is a bacterial disease called scrub typhus.

    Scrub typhus can occur after a person is bitten by chiggers infected with Orientia tsutsugamushi bacteria. According to the BBC, these mites live on plants that flourish after the monsoon rains, and they can hitchhike into people’s homes on firewood. The symptoms of O. tsutsugamushi infection largely overlap with what has been seen in the patients.

    According to the US Center for Disease Control and Prevention (CDC), there are no vaccinations for scrub typhus and it should be treated with the antibiotic doxycycline. The agency recommends covering exposed skin to prevent chigger bites.

    https://www.the-scientist.com/news-opinion/mystery-fever-claims-the...

  • Dr. Krishna Kumari Challa

    Biomedical Innovations from Women Less Likely to be Adopted: Study

    An analysis of scientists’ networks finds discrepancies in the diffusion of novel ideas through communities.

    A study published Monday (August 30) by the National Bureau of Economic Research finds that new ideas in biomedical research are less likely to spread when they are generated by women and minorities than when generated by men.

    The authors of the study, which was not peer-reviewed, used a computational technique called natural language processing to scan titles and abstracts in MEDLINE for novel one, two, or three-word phrases originating in biomedical research papers published between 1980 and 2008. The researchers ranked these phrases by the total number of mentions they received in the year when they first appeared and analyzed the top 0.1 percent of phrases for each year to assess whether each represented an actual new idea or scientific innovation.

    Ideas generated by teams of mostly male innovators were mentioned just over one percent more frequently in subsequent titles and abstracts than ideas generated by mostly female teams over a period of five years after they were first published.

    Biomedical Innovations from Women Less Likely to be Adopted: Study
    An analysis of scientists' networks finds discrepancies in the diffusion of novel ideas through communities.
  • Dr. Krishna Kumari Challa

    Why words become harder to remember as we get older

    As we get older, we find it increasingly difficult to have the right words ready at the right moment, even though our vocabulary actually grows continuously over the course of our lives. Until now, it was unclear why this is. Researchers  have now found out: It is the networks in the brain that change their communication over time. This makes them more inefficient.

    The researchers investigated these connections with the help of two groups - younger study participants between the ages of 20 and 35 and older ones between the ages of 60 and 70. Both groups were asked to name words in the MRI scanner that belong to certain categories, including animals, metals or vehicles.

    It became clear that both age groups were good at finding words. However, the younger ones were somewhat faster. The reason for this could be the different brain activities. For one thing, not only were the language areas themselves more active in the younger ones. They also showed a more intensive exchange within two decisive networks: the network for semantic memory, in which factual knowledge is stored, and the executive network, which is responsible for general functions such as attention and memory.

    The reverse was true for older people. Here, executive areas showed stronger activity, indicating that the task was more difficult for these individuals overall. In addition, the exchange within the crucial networks was less effective than in the younger people. The older group was most likely to benefit from inter-network exchange, but this is associated with losses. Communication within neuronal networks is more efficient and thus faster than between them.

     Why these activity patterns shift with age has not yet been fully explained. One theory, says Martin, is that as people age, they rely more on the linguistic knowledge they have, so exchanges between networks come into focus, while younger people rely more on their fast working memory and cognitive control processes. On the structural level, the loss of grey matter in the brain could also play a role, which is compensated for by the exchange between networks.

    Age-Dependent Contribution of Domain-General Networks to Semantic C...” by Sandra Martin et al. Cerebral Cortex

    https://researchnews.cc/news/8725/Why-words-become-harder-to-rememb...

  • Dr. Krishna Kumari Challa

    Robo Pill

  • Dr. Krishna Kumari Challa

    Sport science: How do swimmers control their front crawl swimming velocity?

    A research team  has reviewed the hydrodynamics literature related to swimming. They identified certain biomechanical aspects, including the relationship between velocity and drag forces, that are not completely understood. This work may help direct future research that could improve the performance of competitive swimmers.

    The recent Tokyo Olympics provided impressive feats of speed in the pool, with elite athletes setting many new Olympic and World records. What viewers might not realize, however, is the complexity of the science underlying the sometimes split-second difference between winning a gold medal and going home empty-handed. Biomechanics, the study of motion of the body, and hydrodynamics, the area of physics dealing with fluid flows, contain many questions that remain poorly understood—and swimming fits right at the intersection of these topics. For swimmers who participate in races, even a tiny advance in knowledge can led to a competitive edge.

    Now, a team of researchers  has drawn together research on front crawl swimming biomechanics, focusing on propulsive and resistive forces at different swimming velocities, to form a more complete picture of the relationships between the critical variables. New knowledge of swimming energetics and fluid mechanics has improved our understanding of factors that determine swimming performance.

    One of the most important relationships to understand is how resistive forces, like drag when moving through the water, depend on the speed of the swimmer. The researchers looked at recent studies that indicated the resistive force increases in proportion to the cube of the velocity. To compensate, swimmers may try to increase their stroke frequency. However, this has limitations. Researchers inferred from experimental and simulation studies that there is a maximum frequency beyond which swimmers cannot further increase swimming velocity due to a change in the angle of attack of the hand that reduces its propulsive force. The different balance of forces at different swimming speeds also means that optimal technique may differ between long-distance and short-distance swimming.

    The team also identified conflicting evidence over the effectiveness of kicking for increasing the speed of high-velocity front crawl. This indicates an opportunity to further optimize competitive swimming technique if future research can further unpack the relevant hydrodynamic factors.

    The researchers found that certain simplified models of swimming often break down when trying to model more realistic conditions. For example, swimmers are not simply 'pushing' or 'pulling' the water to increase their velocity, as some textbooks frame it. This is because the increase in the negative pressure acting on the dorsal side of the hand is crucial for increasing propulsion. Therefore, teaching the proper technique is important, even for phases considered to be non-propulsive.

    Hideki Takagi et al, How do swimmers control their front crawl swimming velocity? Current knowledge and gaps from hydrodynamic perspectives, Sports Biomechanics (2021). DOI: 10.1080/14763141.2021.1959946

    https://phys.org/news/2021-09-swimmers-front-velocity.html?utm_sour...

  • Dr. Krishna Kumari Challa

    Cavendish Gravity Experiment

    A qualitative demonstration of universal gravitation using a torsion balance.

    The Cavendish Experiment Explained
  • Dr. Krishna Kumari Challa

     Fridge-free COVID-19 vaccines  grown in plants and bacteria

    Nanoengineers have developed COVID-19 vaccine candidates that can take the heat. Their key ingredients? Viruses from plants or bacteria.

    The new fridge-free COVID-19 vaccines are still in the early stage of development. In mice, the vaccine candidates triggered high production of neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19. If they prove to be safe and effective in people, the vaccines could be a big game changer for global distribution efforts, including those in rural areas or resource-poor communities.

    What's exciting about this vaccine technology is that is thermally stable, so it could easily reach places where setting up ultra-low temperature freezers, or having trucks drive around with these freezers, is not going to be possible.

    The researchers created two COVID-19 vaccine candidates. One is made from a plant virus, called cowpea mosaic virus. The other is made from a bacterial virus, or bacteriophage, called Q beta.

    Both vaccines were made using similar recipes. The researchers used cowpea plants and E. coli bacteria to grow millions of copies of the plant virus and bacteriophage, respectively, in the form of ball-shaped nanoparticles. The researchers harvested these nanoparticles and then attached a small piece of the SARS-CoV-2 spike protein to the surface. The finished products look like an infectious virus so the immune system can recognize them, but they are not infectious in animals and humans. The small piece of the spike protein attached to the surface is what stimulates the body to generate an immune response against the coronavirus.

    The researchers note several advantages of using plant viruses and bacteriophages to make their vaccines. For one, they can be easy and inexpensive to produce at large scales.

    Another big advantage is that the plant virus and bacteriophage nanoparticles are extremely stable at high temperatures. As a result, the vaccines can be stored and shipped without needing to be kept cold. 

    Trivalent subunit vaccine candidates for COVID-19 and their delivery devices, Journal of the American Chemical Society (2021). DOI: 10.1021/jacs.1c06600

    https://phys.org/news/2021-09-fridge-free-covid-vaccines-grown-bact...

  • Dr. Krishna Kumari Challa

    How do pathogens evolve novel virulence activities and why does it matter?

  • Dr. Krishna Kumari Challa

    Why are planets round?

     Earth is round. So are other planets in the solar system.
    When you drop anything, gravity causes it to fall directly toward the center of the Earth, at least until it hits the ground. Gravity is a force that is caused by nearly everything that has mass. Mass is a measure of how much material there is in anything. It could be in the form of rocks, water, metal, people – anything. Everything material has mass, and therefore everything causes gravity. Gravity always pulls toward the center of mass.

    The Earth and all planets are round because when the planets formed, they were composed of molten material – essentially very hot liquid. Since gravity always points toward the center of a mass, it squeezed the stuff the Earth is made of equally in all directions and formed a ball. When the Earth cooled down and became a solid, it was a round ball. If the Earth didn’t spin, then it would have been a perfectly round planet. Scientists call something that is perfectly round in all directions a “sphere.”

    The gas cloud that the Earth was made from was slowly rotating in one direction around an axis. The top and bottom of this axis are the north and south poles of Earth.

    If you ever played on a merry-go-round, you know that the spinning merry-go-round tends to throw you off. The faster it spins, the harder it is to stay on. This tendency to be flung off is called centrifugal force and pushes the mass on the equator outward. This makes the planet bulge at the equator.

    The faster the spin, the more unround it becomes. Then, when it cools and hardens, it retains that shape. If a molten planet starts off spinning faster, it would be less round and have a bigger bulge.

    The planet Saturn is very oblate – non-spherical – because it rotates very fast. Because of gravity, all planets are round, and because they rotate at different rates, some have fatter equators than their poles. So the shape of the planet and the speed and direction that it rotates depends on the initial condition of the material out of which it forms.

    https://theconversation.com/why-are-planets-round-164903?utm_medium...

  • Dr. Krishna Kumari Challa

    New Mathematical Solutions to An Old Problem in Astronomy

  • Dr. Krishna Kumari Challa

    Hundreds of Medical Journals Just United Together to Issue a Brutally Frank Warning

    Global warming is already affecting people's health so much that emergency action on climate change cannot be put on hold while the world deals with the COVID-19 pandemic, medical journals across the globe warned on Monday.

    Health is already being harmed by global temperature increases and the destruction of the natural world," read an editorial published in more than 220 leading journals ahead of the COP26 climate summit in November.

    Since the pre-industrial era, temperatures have risen around 1.1 degrees Celsius.

    The editorial, written by the editors-in-chief of over a dozen journals including the Lancet, the East African Medical Journal, Brazil's Revista de Saude Publica and the International Nursing Review, said this had caused a plethora of health problems.

    "In the past 20 years, heat-related mortality among people older than 65 years has increased by more than 50 percent," it read.

    "Higher temperatures have brought increased dehydration and renal function loss, dermatological malignancies, tropical infections, adverse mental health outcomes, pregnancy complications, allergies, and cardiovascular and pulmonary morbidity and mortality."

    It also pointed to the decline in agricultural production, "hampering efforts to reduce undernutrition".

    These effects, which hit those most vulnerable like minorities, children, and poorer communities hardest, are just the beginning, it warned.

    https://www.bmj.com/content/374/bmj.n1734

  • Dr. Krishna Kumari Challa

    NASA Testing Electric 'Air Taxi' Prototype Designed to Carry Passengers in The Sky

    NASA is commonly thought of as America's space agency, but its name also emphasizes another research area. The National Aeronautics and Space Administration is also America's civilian aerospace research organization. 

    Electric Vertical Take-Off and Landing Aircraft

  • Dr. Krishna Kumari Challa

    The squid and its giant nerve fibre Part 1

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

    Scientists create artificial cells that mimic living cells' ability to capture, process, and expel material

    Researchers have developed artificial cell-like structures using inorganic matter that autonomously ingest, process, and push out material—recreating an essential function of living cells.

    Their article, published in Nature, provides a blueprint for creating "cell mimics," with potential applications ranging from drug delivery to environmental science.

    A fundamental function of living cells is their ability to harvest energy from the environment to pump molecules in and out of their systems. When energy is used to move these molecules from areas of lower concentration to areas of higher concentration, the process is called active transport. Active transport allows cells to take in necessary molecules like glucose or amino acids, store energy, and extract waste.

    For decades, researchers have been working to create artificial cells—engineered microscopic structures that emulate the features and behavior of biological cells. But these cell mimics tend to lack the ability to perform complex cellular processes like active transport.

    In the Nature study, researchers describe a new, fully synthetic cell mimic that is one step closer to replicating the function of living cells. When deployed in mixtures of different particles, the cell mimics can perform active transport tasks by autonomously capturing, concentrating, storing, and delivering microscopic cargo. These artificial cells are fabricated using minimal ingredients and borrow no materials from biology.

    To design the cell mimics, the researchers created a spherical membrane the size of a red blood cell using a polymer, a stand-in for the cellular membrane that controls what goes in and out of a cell. They pierced a microscopic hole into the spherical membrane creating a nano-channel through which matter can be exchanged, imitating a cell's protein channel.

    But in order to perform the tasks required for active transport, the cell mimics needed a mechanism to power the cell-like structure to pull in and expel material. In a living cell, mitochondria and ATP provide the necessary energy for active transport. In the cell mimic, the researchers added a chemically reactive component inside the nano-channel that, when activated by light, acts as a pump. When light hits the pump, it triggers a chemical reaction, turning the pump into a tiny vacuum and pulling cargo into the membrane. When the pump is switched off, the cargo is trapped and processed inside the cell mimic. And when the chemical reaction is reversed, the cargo is pushed out on demand.

     Transmembrane transport in inorganic colloidal cell mimics, Nature (2021). DOI: 10.1038/s41586-021-03774-y , www.nature.com/articles/s41586-021-03774-y

    https://phys.org/news/2021-09-scientists-artificial-cells-mimic-abi...