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All about Science - to remove misconceptions and encourage scientific temper

Communicating science to the common people

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  • Dr. Krishna Kumari Challa

    The Probability of Another COVID-Level Pandemic Emerging is higher than you think

    a new statistical study has discovered that large pandemics are much more common than you might expect. In fact, the team found that a pandemic with a similar level of impact to COVID-19 has around a 2 percent probability of occurring each year.

    When you add that up across an entire lifetime, this means we each have a 38 percent chance of experiencing a big one at least once, and the odds look set to get worse with time.

    The most important takeaway is that large pandemics like COVID-19 and the Spanish flu are relatively likely.

    The team looked at the historical record of epidemics from the year 1600 until now. They found 476 documented epidemics, around half of which had a known number of casualties. About 145 caused less than 10,000 deaths, while 114 others we know existed, but not the number of deaths.

    Importantly, infectious diseases that are currently active were excluded from the analysis – so that means no COVID-19, HIV, or malaria.

    The team used detailed modelling with a generalized Pareto distribution to analyze the data, finding that the yearly number of epidemics is immensely variable, and an extreme epidemic like the Spanish flu of 1918-1920 had a probability of occurring somewhere between 0.3 and 1.9 percent each year over the last 400 years.

    "The slow decay of probability with epidemic intensity implies that extreme epidemics are relatively likely, a property previously undetected due to short observational records and stationary analysis methods

    part 1

  • Dr. Krishna Kumari Challa

    In the last 50 years, we've seen increasing levels of new pathogens spreading through humans. SARS-CoV-2 is the most obvious example, but even in the last few decades we've had swine flu, bird flu, Ebola, and many, many more.

    "Together with recent estimates of increasing rates of disease emergence from animal reservoirs associated with environmental change," the team writes, "this finding suggests a high probability of observing pandemics similar to COVID-19 (probability of experiencing it in one's lifetime currently about 38 percent), which may double in coming decades.

    So, even while we are recovering from a current outbreak, it's important that we don't assume we won't see another life-changing pandemic soon enough.

    In fact, if we play our cards right, our response and resources for COVID-19 can prepare us for the next pandemic.

    https://www.pnas.org/content/118/35/e2105482118

    part 2

  • Dr. Krishna Kumari Challa

    Why the changing colour of our streetlights could be a danger for insect populations

    Life on Earth has evolved alongside predictable cycles of day and night. But this pattern has become increasingly blurred. Between 2012 and 2016, satellite measurements revealed that the global area polluted by artificial light grew by 2% each year, intruding ever deeper into biodiversity hotspots like tropical forests.

    In this context, there is an important change taking place in the world: the replacement of older, less energy-efficient sodium street-lighting with white LEDs.

    LEDs used in streetlights typically emit white light, while sodium lamps have a characteristic yellow glow – as seen in the picture below. This change in the colour of artificial light is predicted to have major consequences for wildlife. That’s because white LEDs emit light across the entire visible spectrum. The more wavelengths emitted, the greater the diversity of species and biological processes that are likely to be disrupted.

    Insects are known to be more sensitive to shorter, bluer wavelengths of light, which are largely absent from sodium lighting. Biological processes that are controlled by daylight and internal circadian rhythms, such as reproduction, are more likely to be disrupted or prevented by white LEDS.

    A study results published in Science Advances recently were striking. Lighting reduced the numbers of caterpillars by between one half and one third. Lit areas almost universally had lower numbers than their darker counterparts. Sites with white LEDs also had a steeper reduction in numbers compared to sites with sodium lamps.

    We suspect the reason there were fewer caterpillars in lit areas was because the lighting prevented females from laying eggs, a behaviour that has evolved in darkness. In addition, adult moths can be drawn up to streetlights, where they’re easy pickings for bats. Our recent review article revealed many other plausible mechanisms through which lighting could cause population declines throughout the moths’ life cycles.

    https://advances.sciencemag.org/content/7/35/eabi8322

    https://theconversation.com/why-the-changing-colour-of-our-streetli...

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

    A Badge That Measures Exposures to Dangerous Chemicals

  • Dr. Krishna Kumari Challa

    In a first, scientists capture a 'quantum tug' between neighboring water molecules

    Water is the most abundant yet least understood liquid in nature. It exhibits many strange behaviors that scientists still struggle to explain. While most liquids get denser as they get colder, water is most dense at 39 degrees Fahrenheit, just above its freezing point. This is why ice floats to the top of a drinking glass and lakes freeze from the surface down, allowing marine life to survive cold winters. Water also has an unusually high surface tension, allowing insects to walk on its surface, and a large capacity to store heat, keeping ocean temperatures stable.

    Now, a team of researchers   has made the first direct observation of how hydrogen atoms in water molecules tug and push neighboring water molecules when they are excited with laser light. Their results, published in Nature today, reveal effects that could underpin key aspects of the microscopic origin of water's strange properties and could lead to a better understanding of how water helps proteins function in living organisms.

    Each water molecule contains one oxygen atom and two hydrogen atoms, and a web of hydrogen bonds between positively charged hydrogen atoms in one molecule and negatively charged oxygen atoms in neighboring molecules holds them all together. This intricate network is the driving force behind many of water's inexplicable properties, but until recently, researchers were unable to directly observe how a water molecule interacts with its neighbors.

    The low mass of the hydrogen atoms accentuates their quantum wave-like behavior. This study is the first to directly demonstrate that the response of the hydrogen bond network to an impulse of energy depends critically on the quantum mechanical nature of how the hydrogen atoms are spaced out, which has long been suggested to be responsible for the unique attributes of water and its hydrogen bond network.

    Direct observation of ultrafast hydrogen bond strengthening in liquid water, Nature (2021). DOI: 10.1038/s41586-021-03793-9 , www.nature.com/articles/s41586-021-03793-9

    https://phys.org/news/2021-08-scientists-capture-quantum-neighborin...

  • Dr. Krishna Kumari Challa

    YouTube says it removed 1mn 'dangerous' videos on COVID-19

    YouTube said Wednesday it has removed more than one million videos with "dangerous coronavirus misinformation" since the start of the COVID-19 pandemic.

    YouTube said in a blog post it relies on "expert consensus from health organizations," including the US Centers for Disease Control and the World Health Organization, but noted that, in some cases, "misinformation is less clear-cut" as new facts emerge.

    YouTube said it was working to accelerate the process for removing videos with misinformation while simultaneously delivering those from authoritative sources.

    IANS

  • Dr. Krishna Kumari Challa

    Protecting gardens and crops from insects using the 'smell of fear'

    For home gardeners and farmers, herbivorous insects present a major threat to their hard work and crop yields. The predator insects that feed on these bugs emit odors that pests can sense, which changes the pests' behavior and even their physiology to avoid being eaten. With bugs becoming more resistant to traditional pesticides, researchers now report they have developed a way to bottle the "smell of fear" produced by predators to repel and disrupt destructive insects naturally without the need for harsh substances.

    Smell of fear: Harnessing predatory insect odor cues as a pest management tool for herbivorous insects, ACS Fall 2021.

  • Dr. Krishna Kumari Challa

    New class of habitable exoplanets represent a big step forward in the search for life

    A new class of exoplanet very different to our own, but which could support life, has been identified by astronomers, which could greatly accelerate the search for life outside our Solar System.

    In the search for life elsewhere, astronomers have mostly looked for planets of a similar size, mass, temperature and atmospheric composition to Earth. However, astronomers  now think there are more promising possibilities out there.

    The researchers have identified a new class of habitable planets, dubbed 'Hycean' planets—hot, ocean-covered planets with hydrogen-rich atmospheres—which are more numerous and observable than Earth-like planets.

    The researchers say the results, reported in The Astrophysical Journal, could mean that finding biosignatures of life outside our Solar System within the next two or three years is a real possibility.

    Many of the prime Hycean candidates identified by the researchers are bigger and hotter than Earth, but still have the characteristics to host large oceans that could support microbial life similar to that found in some of Earth's most extreme aquatic environments.

    These planets also allow for a far wider habitable zone, or 'Goldilocks zone', compared to Earth-like planets. This means that they could still support life even though they lie outside the range where a planet similar to Earth would need to be in order to be habitable.

    Habitability and Biosignatures of Hycean Worlds, Astrophysical Journal (2021). doi.org/10.3847/1538-4357/abfd9c

    part1

  • Dr. Krishna Kumari Challa

     researchers to identify a new class of planets, Hycean planets, with massive planet-wide oceans beneath hydrogen-rich atmospheres. Hycean planets can be up to 2.6 times larger than Earth and have atmospheric temperatures up to nearly 200 degrees Celsius, but their oceanic conditions could be similar to those conducive for microbial life in Earth's oceans. Such planets also include tidally locked 'dark' Hycean worlds that may have habitable conditions only on their permanent night sides, and 'cold' Hycean worlds that receive little radiation from their stars.

    Planets of this size dominate the known exoplanet population, although they have not been studied in nearly as much detail as super-Earths. Hycean worlds are likely quite common, meaning that the most promising places to look for life elsewhere in the Galaxy may have been hiding in plain sight.

    However, size alone is not enough to confirm whether a planet is Hycean: other aspects such as mass, temperature and atmospheric properties are required for confirmation.

    https://phys.org/news/2021-08-class-habitable-exoplanets-big-life.h...

    part 2

  • Dr. Krishna Kumari Challa

    Study identifies nearly 600 genetic loci associated with anti-social behavior, alcohol use, opioid addiction and more

    An analysis of data from 1.5 million people has identified 579 locations in the genome associated with a predisposition to different behaviors and disorders related to self-regulation, including addiction and child behavioral problems.

    With these findings, researchers have constructed a genetic risk score—a number reflecting a person's overall genetic propensity based on how many risk variants they carry—that predicts a range of behavioral, medical and social outcomes, including education levels, obesity, opioid use disorder, suicide, HIV infections, criminal convictions and unemployment.

    [This study] illustrates that genes don't code for a particular disorder or outcome; there are no genes 'for' substance use disorder, or 'for' behavior problems. Instead, genes influence the way our brains are wired, which can make us more at risk for certain outcomes. In this case, we find that there are genes that broadly influence self-control or impulsivity, and that this predisposition then confers risk for a variety of life outcomes.

    Multivariate analysis of 1.5 million people identifies genetic associations with traits related to self-regulation and addiction, Nature Neuroscience (2021). DOI: 10.1038/s41593-021-00908-3 , www.nature.com/articles/s41593-021-00908-3

    https://medicalxpress.com/news/2021-08-genetic-loci-anti-social-beh...

  • Dr. Krishna Kumari Challa

    Plant roots and animals embryos rely on the same chemical for successful development

    What do frog eggs have in common with anti-aging creams? Their success depends on a group of chemical compounds called retinoids, which are capable of generating and re-generating tissues. A new study in plants shows that retinoids' tissue-generating capacities are also responsible for the appropriate development of roots.

    In a new study, appearing August 26 in the journal Science, a research team led by Alexandra Dickinson, assistant professor at the University of California, San Diego, and Philip Benfey, the Paul Kramer Distinguished Professor of Biology at Duke University, identifies the compound that plays a key role in triggering the development of plants' lateral roots.

    The research team had a good suspect: retinal, a type of retinoid, looked like it would fit the bill.

    In humans, as well as all vertebrate animals, turning a fertilized egg into an embryo with a little beating heart requires that stem cells differentiate, specialize, and generate specific tissues, such as bones, blood vessels and a nervous system. This process is kickstarted and regulated by retinal. Animals can't produce their own retinal, though, they must ingest it from plants, or from animals that eat plants.

    "We know plants have the ability to produce this compound, that it's very important for animal development, and so it was very tempting to check its role in plant development as well.

    A plant lipocalin promotes retinal-mediated oscillatory lateral root initiation, Science (2021). DOI: 10.1126/science.abf7461

    https://phys.org/news/2021-08-roots-animals-embryos-chemical-succes...

    **

  • Dr. Krishna Kumari Challa

    Migraines protect against diabetes

    Migraines protect against diabetes!

    People who get migraines are less likely to develop type 2 diabetes, while some people who develop diabetes become less prone to migraines. Today, scientists studying the link between these conditions report how the peptides that cause migraine pain can influence production of insulin in mice, possibly by regulating the amount of secreted insulin or by increasing the number of pancreatic cells that produce it. These findings could improve methods to prevent or treat diabetes.

    Researchers already knew that two peptides in the nervous system—calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP)—play a major role in causing the pain of migraines. These same peptides, along with the related peptide amylin, are also found in the pancreas. There, they influence release of insulin from beta cells.

    Insulin regulates blood sugar levels by helping other cells in the body absorb glucose and either store it or use it for energy. In type 2 diabetes, those other cells become resistant to insulin and less capable of absorbing glucose, leading to high blood sugar levels. The beta cells initially compensate by ramping up insulin production but eventually wear themselves out and die, exacerbating the issue.

    Because CGRP and PACAP can seemingly protect against diabetes, researchers worry that the anti-CGRP and anti-PACAP treatments under development or already on the market for migraine could have the unintended consequence of increasing the risk of diabetes. In addition, these peptides are involved in numerous other beneficial functions in the body, such as blood vessel dilation. So scientists are also exploring the potential risks of altering the peptides' activity.

    https://www.acs.org/content/acs/en/pressroom/newsreleases/2021/augu...

    https://medicalxpress.com/news/2021-08-migraines-diabetes.html?utm_...

  • Dr. Krishna Kumari Challa

    Female hummingbirds avoid harassment by looking as flashy as males

    Much like in human society, female hummingbirds have taken it into their own hands to avoid harassment. By watching white-necked Jacobin hummingbirds in Panama, researchers discovered that over a quarter of females have the same brightly colored ornamentation as males, which helps them avoid aggressive male behaviors during feeding, such as pecking and body slamming. This paper appears August 26 in the journal Current Biology.

    All of the Jacobin  juvenile females  had showy colors. For birds that's really unusual because you usually find that when the males and females are different the juveniles usually look like the adult females, not the adult males, and that's true almost across the board for birds. It was unusual to find one where the juveniles looked like the males. So it was clear something was at play.

    Male white-necked Jacobin hummingbirds are known to have bright and flashy colors, with iridescent blue heads, bright white tails, and white bellies. Female Jacobins, on the other hand, tend to be drabber in comparison, with a muted green, gray, or black colors that allow them to blend into their environment. Researchers, however, found that around 20% of adult females have showy colors like males.

    As juveniles, all females have the showy colors, but this 20% of females doesn't change to the muted color as they age. It is not clear whether this phenomenon is genetic, by the choice of the hummingbird, or due to environmental factors. However, the researchers found that it is probably the result of the female hummingbirds trying to evade harassment, including detrimental aggression during mating or feeding.

    To learn why some female hummingbirds kept their showy colors, the researchers set up a scenario with stuffed hummingbirds on feeders and watched as real hummingbirds interacted with them. They found that hummingbirds harassed mainly the muted colored female hummingbirds, which is in favor of the hypothesis that the showy colors are caused by social selection. Furthermore, most females had showy colors during their juvenile period and not during their reproductive period. This means that the only time they had showy colors is precisely during the period when they're not looking for mates. In combination with other results from the study, this indicates that it is not sexual selection causing the phenomenon.

    Current Biology, Falk et al.: "Male-like ornamentation in female hummingbirds results from social harassment rather than sexual selection" www.cell.com/current-biology/f … 0960-9822(21)01033-2 , DOI: 10.1016/j.cub.2021.07.043

    https://phys.org/news/2021-08-female-hummingbirds-flashy-males.html...

  • Dr. Krishna Kumari Challa

    Breaking Bad Chemicals With Bacterial Detoxifiers

    India’s landfills are home to tiny environmental detoxifiers—bacteria that transform chemical wastes into harmless substances.

    While bacteria get a bad rap as disease-causing agents, some of these tiny organisms may just be the rescuers of the environment. An international team found that bacteria from Indian landfills could detoxify chemical wastes called hexabromocyclodecane (HBCD), publishing their study in Chemosphere.

    For a long time, industrial production has been a major culprit of environmental pollution, releasing hazardous waste like HBCD. At peak production, HBCD hit scales of 10,000 tons a year as a flame retardant used in textile manufacturing and integrated in plastics for electronic devices.

    By the time the chemical was banned worldwide in 2014, the damage had been done. As a long-lived environmental toxin, HBCD had already seeped into sewages, soil and the air—found even in the food chain and consequently, in human blood samples and breast milk.

    Given HBCD’s persistence in the surroundings, researchers have been searching for ways to detoxify the chemical pollution from the past to create a cleaner future. Scientists from the University of Delhi and the India Habitat Center, together with collaborators from Sweden, found a solution from nature itself—showing that Sphingobium indicum bacteria inhabiting India’s landfills could digest these chemicals.

    The detoxifying abilities of these bacteria come from an enzyme called LinA, which is involved in metabolizing another now-banned insecticide and chemical sibling of HBCD. Known as biological catalysts, enzymes speed up reactions like the breakdown of chemicals.

    On the designated binding site, the toxin attaches itself to LinA, similar to a key being inserted into a lock. HBCD rapidly splits up into non-toxic fragments, which are then released to make room for the next chemical to latch onto the enzyme’s binding site.

    By genetically modifying the bacteria, the team also altered the structure of the enzymes they produced. While LinA enzymes are highly selective about the molecules they can accept on the binding site, the genetic changes led to a more spacious site for accommodating larger chemicals.

    According to the researchers, these experiments highlight the possibility of designing enzymes that can degrade other toxins besides HBCD. Through modifying biological structures, biotransformation may be key to engineering useful bacterial enzymes for remediating heavily polluted environments.

     Heeb et al. (2021) Transformation of ε-HBCD with the Sphingobium indicum Enzymes LinA1, LinA2 and LinATM, a Triple Mutant of LinA2.

    https://www.asianscientist.com/2021/08/in-the-lab/bacteria-chemical...

  • Dr. Krishna Kumari Challa

    COVID-19, not vaccination, presents biggest blood clot risks: study

    COVID-19, not vaccination, presents biggest blood clot risks

    Part 1

  • Dr. Krishna Kumari Challa

    Researchers from the University of Oxford have recently announced the results of a study into thrombocytopenia (a condition with low platelet counts) and thromboembolic events (blood clots) following vaccination for COVID-19, some of the same events which have led to restricted use of the Oxford-AstraZeneca vaccine in a number of countries.

    Writing in the British Medical Journal (BMJ), they detail the findings from over 29 million people vaccinated with first doses of either the ChAdOx1 nCov-19 "Oxford-AstraZeneca" vaccine or the BNT162b2 mRNA "Pfizer-BioNTech' vaccine. They conclude that with both of these vaccines, for short time intervals following the first dose, there are increased risks of some hematological and vascular adverse events leading to hospitalization or death.

    However, people should be aware of these increased risks after COVID-19 vaccination and seek medical attention promptly if they develop symptoms, but also be aware that the risks are considerably higher and over longer periods of time if they become infected with SARS-CoV-2.

    The authors further note that the risk of these adverse events is substantially higher and for a longer period of time, following infection from the SARS-CoV-2 "coronavirus" than after either vaccine.

    All of the coronavirus vaccines currently in use have been tested in randomized clinical trials, which are unlikely to be large enough to detect very rare adverse events. When rare events are uncovered, then regulators perform a risk-benefit analysis of the medicine; to compare the risks of the adverse events if vaccinated versus the benefits of avoidance of the disease—in this case, COVID-19.

    part 2

  • Dr. Krishna Kumari Challa

    This enormous study, using data on over 29 million vaccinated people, has shown that there is a very small risk of clotting and other blood disorders following first dose COVID-19 vaccination. Though serious, the risk of these same outcomes is much higher following SARS-CoV-2 infection.

    Julia Hippisley-Cox et al, Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study, BMJ (2021). DOI: 10.1136/bmj.n1931

    https://medicalxpress.com/news/2021-08-covid-vaccination-biggest-bl...

    part3

  • Dr. Krishna Kumari Challa

    Mutation rate of COVID-19 virus is at least 50 percent higher than previously thought

    The virus that causes COVID-19 mutates almost once a week—significantly higher than the rate estimated previously—according to a new study by scientists . Their findings indicate that new variants could emerge more quickly than thought previously.

    SARS-CoV-2, the virus that causes COVID-19, was previously thought to mutate about once every two weeks. However, new research shows that this estimate overlooked many mutations that happened but were never sequenced.

    Viruses regularly mutate, for example when mistakes are made in copying the genomes whilst the virus replicates.

    Usually when we consider natural selection, we think about new mutations that have an advantage and so spread, such as the Alpha and Delta variants of COVID-19. This is known as Darwinian selection or positive selection.

    However, most mutations are harmful to the virus and reduce its chances of surviving—this is called purifying or negative selection. These negative mutations don't survive in the patient long enough to be sequenced and so are missing from calculations of the mutation rate.

    Allowing for these missing mutations, the team estimates that the true mutation rate of the virus is at least 50% higher than previously thought.

    The findings, published in Genome Biology and Evolution, reinforce the need to isolate individuals with immune systems that struggle to contain the virus.  These findings mean that if a patient suffers COVID-19 for more than a few weeks, the virus could evolve which could potentially lead to new variants.

    The Alpha variant is thought to be the result of evolution of the virus within an individual who was unable to clear the infection.

    It's not all bad news because most individuals transmit and clear the virus before it mutates all that much, meaning that the chance of evolution within one patient isn't usually that high. However, this new estimate of the mutation rate indicates that there is more scope for evolution of the virus within such individuals than scientists assumed.

     Atahualpa Castillo Morales et al, Causes and consequences of purifying selection on SARS-CoV-2, Genome Biology and Evolution (2021). DOI: 10.1093/gbe/evab196

    https://phys.org/news/2021-08-mutation-covid-virus-percent-higher.h...

  • Dr. Krishna Kumari Challa

    Covid-19 not developed as biological weapon: US intelligence community

    SARS-CoV-2, the virus that causes Covid-19, was 'not developed' as a biological weapon, the US intelligence community has concluded in a report

    SARS-CoV-2, the virus that causes COVID-19, was "not developed" as a biological weapon, the US intelligence community has concluded in a report.

    The Director of National Intelligence in a report, prepared at the direction of the president, on Friday said SARS-CoV-2 probably emerged and infected humans through an initial small-scale exposure that occurred no later than November 2019 with the first known cluster of COVID-19 cases arising in Wuhan, China in December 2019.

    However, there was no unanimity among the intelligence community (IC) on the origins of the 

    The virus was not developed as a biological weapon. Most agencies also assess with low confidence that SARS-CoV-2 probably was not genetically engineered; however, two agencies believe there was not sufficient evidence to make an assessment either way, said the unclassified version of the report.

    The IC also assesses that China's officials did not have foreknowledge of the virus before the initial outbreak of COVID-19 emerged, it said.

    After examining all available intelligence reporting and other information, though, the IC remains divided on the most likely origin of COVID-19. All agencies assess that two hypotheses are plausible: natural exposure to an infected animal and a laboratory-associated incident, the report said.

    Four IC elements and the National Intelligence Council assess with low confidence that the initial SARS-CoV-2 infection was most likely caused by natural exposure to an animal infected with it or a close progenitor virus-a virus that probably would be more than 99 per cent similar to SARS-CoV-2.

    These analysts give weight to Chinese officials' lack of foreknowledge, the numerous vectors for natural exposure, and other factors, the report said.

    part 1

  • Dr. Krishna Kumari Challa

    One IC element assesses with moderate confidence that the first human infection with SARS-CoV-2 most likely was the result of a laboratory-associated incident, probably involving experimentation, animal handling, or sampling by the Wuhan Institute of Virology. These analysts give weight to the inherently risky nature of work on coronaviruses, it said.

    Analysts at three IC elements remain unable to coalesce around either explanation without additional information, with some analysts favouring natural origin, others a laboratory origin, and some seeing the hypotheses as equally likely. Variations in analytic views largely stem from differences in how agencies weigh intelligence reporting and scientific publications, and intelligence and scientific gaps, the report said.

    Press Trust of India

    https://www.business-standard.com/article/current-affairs/covid-19-...

    https://www.dni.gov/index.php/newsroom/reports-publications/reports...

    https://www.nature.com/articles/d41586-021-02366-0

  • Dr. Krishna Kumari Challa

    If You See Square Waves, Get Out of the Water!

  • Dr. Krishna Kumari Challa

    We Can Make Powerful Nature-Inspired 'Pesticides' Without Poison, Scientists Say

    While no one enjoys seeing carefully nurtured crops destroyed by hordes of hungry insects, the most common way to prevent it – the use of insecticides – is causing massive ecological problems.

    Some are wreaking havoc on bee populations globally, killing birds and piling onto the challenges already faced by endangered species. Thankfully, insecticides are generally only in our food at low levels, but they do harm humans who are highly exposed to them too, like the workers growing our crops

    They also destroy predatory insect populations, which just makes the problem of crop pests worse in the long term - with fewer pest enemies around to keep their numbers in check.

    One alternative that researchers and farmers have been putting to the test is the use of predatory insects to control the problematic plant eaters. However, this approach, known as biological control, has its own challenges.

    While insecticides can target multiple pest species, this is a lot harder to achieve when relying on natural predators. Releasing multiple predators could just lead to them preying on each other, or competing with each other for the same pest, as predators may not always target their intended species.

    The predators are also very reliant on environmental conditions – temperature and day length can alter their behavior so they may only be effective during certain seasons. This, along with the fact that some pests are invasive and have no native predators means some pesticides may still need to be used, which can then also impact the predators.

    part 1

  • Dr. Krishna Kumari Challa

    So insect ecologists Jessica Kansman and Sara Hermann are looking into ways of tweaking the use of pest species' natural enemies to make it more practical. They presented results of their progress at this week's meeting of the American Chemical Society.

    In a series of trials the researchers let collard-snacking aphids (Myzus persicae) choose between the scent of leaves with predatory ladybugs (Harmonia axyridis) on them or the smell of leaves with no ladybug.

    They found exposure to the ladybug scent impacted the aphids' plant choices and even reduced their reproductive rate.

    "Our early work has shown that these fear-based responses can change insect behaviors in ways that reduce their damage on these crop plants.

    Preliminary field tests using three methoxypyrazine compounds (which we humans would recognize as the smell of ladybugs) isolated from ladybug stink have produced promising results - with aphids avoiding the sprayed collard crops as if ladybugs were present.

    "The beauty of these compounds being specific to these insects is that it's an honest cue. The use of natural enemy odor cues is a promising future direction for applied chemical ecology in sustainable pest management

    https://scitechdaily.com/using-the-smell-of-fear-to-protect-gardens...

    https://www.sciencealert.com/researchers-propose-harnessing-the-ste...

    part2

  • Dr. Krishna Kumari Challa

    Protecting gardens and crops from insects using the ‘smell of fear’

  • Dr. Krishna Kumari Challa

    Combo therapy cuts risk of heart attacks and strokes in half

    A combination therapy of aspirin, statins and at least two blood pressure medications given in fixed doses can slash the risk of fatal cardiovascular disease (CVD) by more than half, says an international study.

    The fixed-dose combination (FDC) therapies were examined both with and without aspirin versus control groups in a combined analysis of more than 18,000 patients without prior CVD from three large clinical trials. FDCs including aspirin cut the risk of heart attacks by 53 percent, stroke by 51 percent, and deaths from cardiovascular causes by 49 percent.

    This combination, either given separately or combined as a polypill, substantially reduces fatal and non-fatal CVD events.

    The largest effects are seen with treatments that include blood pressure lowering agents, a statin and aspirin together, which can reduce fatal and non-fatal cardiovascular events by about half.

    The benefits are consistent at different blood pressure levels, cholesterol levels and with or without diabetes, but larger benefits may occur in older people.

     Philip Joseph et al, Fixed-dose combination therapies with and without aspirin for primary prevention of cardiovascular disease: an individual participant data meta-analysis, The Lancet (2021). DOI: 10.1016/S0140-6736(21)01827-4

    https://medicalxpress.com/news/2021-08-combo-therapy-heart.html?utm...

  • 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-...

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  • Dr. Krishna Kumari Challa

    A gecko-inspired robot's crash-landing correction