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  • Dr. Krishna Kumari Challa

    Pulse oximeter measurements of blood oxygen levels are unreliable in assessing severity of Covid-19 pneumonia

    The severity of Covid-19 pneumonia can be difficult to assess in people from different ethnic groups, due to inaccurate readings from a device that measures the level of oxygen in the blood of patients.

    The findings of the research, published in the European Respiratory Journal, show that pulse oximeters gave false readings of nearly 7% higher in a group of patients of Mixed ethnicity with Covid-19, compared to White patients at just over 3%. There were also falsely high readings in patients with both Black and Asian ethnicity, which could delay patients receiving the best and most timely treatment for the virus.

    Pulse oximetry is a non-invasive test that measures the oxygen saturation level of the blood. It can rapidly detect even small changes in oxygen levels. These levels show how efficiently blood is carrying oxygen to the extremities furthest from the heart, including the arms and legs. Medical professionals routinely use them in primary care and critical care settings like emergency rooms or hospitals to monitor the clinical status of their patients.

    The light wave transmission that this technology uses is modified by skin pigmentation and may vary by skin colour. A recent study reported different outputs in patients with Black skin compared to patients with White skin, which has the potential to adversely affect patient care. This led to the Food and Drink Administration in the USA releasing an expression of concern about the accuracy of pulse oximeters in 2021, which led to the current study.

    Researchers  made use of the electronic datasets that are collected for clinical use in real time, but archived and available to answer important clinical questions and improve both patient care and patient safety in the future. The NUH Covid-19 Patient Safety Database is anonymised to allow lessons to be learned without compromising individual patient confidentiality. The team included clinicians, managers, statisticians, computer analysts, software coders and data warehouse archivists.

    The team of experts from Nottingham used data from patients with Covid-19 infection to look at the difference in blood oxygen levels as measured by pulse oximetry and arterial blood gas tests, spilt into different ethnic groups over a wide range of oxygen saturations. Arterial blood gas tests measure the levels of oxygen in the blood from an artery, and represent the gold standard measurement for oxygen levels.

    Part1

  • Dr. Krishna Kumari Challa

    The team used electronic data for patients admitted to Nottingham University Hospitals NHS Trust between February 2020 and September 2021 with Covid-19 infection. Pulse oximetry measurements with a paired blood gas measurement within a half an hour window were compared.

    Mean differences between pulse oximetry and blood gas oxygen saturations were recorded by ethnicity of White, Mixed, Asian, and Black patients, and were also split up by level of oxygen saturation as measured by arterial blood gases.

    There were differences in oxygen saturations (amounts of oxygen in the blood), between the pulse oximetry arterial blood gas readings in all groups. The highest difference was in the Mixed ethnicity group which was nearly 7% higher in the oximetry reading, with the lowest in the White group at 3.2% higher than the true measurement from arterial blood gases. A reading of 5.4% higher using pulse oximetry was found in the Black group of participants and 5.1% higher in the Asian population.

    The difference between the readings also increased in the clinically important range of 85 to 89%, when many clinical decisions are made. Mean values as measured by pulse oximeter were higher than reality in individuals with a recorded Black and Asian ethnicity, compared to those of a White ethnicity.

    The findings of the research are important as high levels of skin pigmentation are associated with ethnic groups who have a poorer outcome from Covid-19 infection, and would require the most accurate oxygen measurements available in order to deliver the most appropriate and timely treatment.

    1. Colin J Crooks, Joe West, Joanne R Morling, Mark Simmonds, Irene Juurlink, Steve Briggs, Simon Cruickshank, Susan Hammond-Pears, Dominick Shaw, Timothy R Card, Andrew W Fogarty. Pulse oximeters' measurements vary across ethnic groups: An observational study in patients with Covid-19 infection. European Respiratory Journal, 2022; 2103246 DOI: 10.1183/13993003.03246-2021

    https://researchnews.cc/news/11340/Pulse-oximeter-measurements-of-b...

    Part 2

  • Dr. Krishna Kumari Challa

    Morphological fingerprinting could help identify side effects and new bioactive compounds in drug discovery

    Pharmaceutical researchers speak of a hit when they come across a promising substance with a desired effect in early drug discovery. Unfortunately, hits are rarely bull's-eyes, often showing undesirable side effects that not only complicate the search for new hits, but also the subsequent development into a drug. A new study  could now help to better identify one of the most frequently observed side effects already in early drug discovery, but also to find new bioactivities.

    The most commonly used cancer drugs contain active substances that manipulate the cell's cytoskeleton by binding to microtubules. This can disrupt cell division as well as impair other essential processes, and leads to cell death. Such an effect is of course not desirable for other therapies. However, microtubules' surface has many deep binding pockets that makes them particularly susceptible to modulation by a wide variety of chemical substances with diverse chemical scaffolds.

    In the search for and development of new active substances, the study of known side effects plays a crucial role, especially when one considers that about 13 years and more than one billion US dollars are needed to develop a new drug. Although there are already standardized test procedures (screens) for identifying undesirable side effects, they certainly do not cover all targets in cells, often do not correctly reflect the cellular context, or they allow targets to be overlooked, e.g. binding to tubulin. Thus, drug discovery is always biased to a certain extent.

    Researchers now  used a new strategy to reliably detect side effects, such as the disruption of microtubules, at an early stage of the search for bioactive compounds. To do this, the researchers employed the so-called "cell painting" approach. Here, several functional areas of the cell are stained and then examined microscopically for changes after the addition of chemical substances. This enables recording hundreds of cellular parameters in a single morphological fingerprint. If one detects similarity of this fingerprint to those of known reference substances, conclusions about the effect of the unknown substance can be drawn. The value of this approach lies in the possibility of creating fingerprints for thousands of substances in a high-throughput process. This way, the researchers revealed that more than 1% of about 15,000 studied substances had a tubulin-modulating effect. Among them was also a large number of known reference substances for which an influence on tubulin was previously unknown.

    Part 1

  • Dr. Krishna Kumari Challa

    Reference substances play an essential role in the interpretation of a screen, so they should be carefully evaluated and tested. The compounds identified by the cell painting show a wide variety of chemical scaffolds and even small chemical modifications can have a dramatic impact on the tubulin-binding properties of a compound. This risk is ubiquitous, especially during the compound optimization phase, where existing atoms are exchanged or removed and new atoms are added in order to improve the pharmacological properties. Additional morphological profiling during the search for hits and their optimization could not only help unmask side effects such as tubulin modulation early on, but also identify desired and new bioactivities. Moreover, this approach could save time and money as it helps to early assess whether a promising substance has what it takes to become a useful compound or not.

    Mohammad Akbarzadeh, Ilka Deipenwisch, Beate Schoelermann, Axel Pahl, Sonja Sievers, Slava Ziegler, Herbert Waldmann. Morphological profiling by means of the Cell Painting assay enables identification of tubulin-targeting compounds. Cell Chemical Biology, 2021; DOI: 10.1016/j.chembiol.2021.12.009

    https://researchnews.cc/news/11353/Morphological-fingerprinting-cou...

    Part 2

  • Dr. Krishna Kumari Challa

    Scientists uncover how the shape of melting ice depends on water temperature

    A team of mathematicians and physicists has discovered how ice formations are shaped by external forces, such as water temperature. Its newly published research may offer another means for gauging factors that cause ice to melt.

    The shapes and patterning of ice are sensitive indicators of the environmental conditions at which it melted, allowing researchers to 'read' the shape to infer factors such as the ambient water temperature. This  helps to understand how melting induces unusual flow patterns that in turn affect melting, which is one of the many complexities affecting the ice on our planet.

    The researchers studied, through a series of experiments, the melting of ice in water and, in particular, how the water temperature affects the eventual shapes and patterning of ice. To do so, they created ultra-pure ice, which is free of bubbles and other impurities. The team recorded the melting of ice submerged into water tanks in a "cold room," which is similar to a walk-in refrigerator whose temperature is controlled and varied.

    They focused on the cold temperatures—0 to 10 degrees Celsius—at which ice in natural waters typically melts, and  found a surprising variety of shapes that formed. 

    Specifically, at very cold temperatures—those under about 5 degrees C—the pieces take on the shape of a spike or "pinnacle" pointing downward—similar to an icicle, but perfectly smooth (with no ripples). For temperatures above approximately 7 degrees C, the same basic shape forms, but upside down—a spike pointing upward. For in between temperatures, the ice has wavy and rippled patterns melted into its surface. Similar patterns, called "scallops," are found on icebergs and other ice surfaces in nature.

    These shape differences are due to changes in water flows, which are determined by their temperatures.

    Part 1

  • Dr. Krishna Kumari Challa

    Melting causes gradients in the temperature of the water near the ice, which causes the liquid at different places to have different densities. This generates flows due to gravity—with heavier liquid sinking and lighter fluid rising—and such flows along the surface lead to different rates of melting at different locations and thus changes in shape.

    The strange bit of physics is that liquid water has a highly unusual dependence of density on temperature, in particular a maximum of density at about 4 degrees C. "This 'density anomaly' makes water unique in comparison to other fluids."

    The research shows that this property is responsible for producing very different flows, depending on the precise value of the water temperature. The downward pinnacles at low temperatures are associated with upward flows, while the upward pinnacles have downward flows. The scalloped patterns form because upward flows very near the surface interact with downward flows further away, destabilizing into vortices that carve pits into the ice.

    Scott Weady et al, Anomalous Convective Flows Carve Pinnacles and Scallops in Melting Ice, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.128.044502

    https://phys.org/news/2022-01-scientists-uncover-ice-temperature.ht...

    Part 2

  • Dr. Krishna Kumari Challa

    A pill that releases RNA in the stomach could offer a new way to administer vaccines

    Like most vaccines, RNA vaccines have to be injected, which can be an obstacle for people who fear needles. Now, a team of  researchers has developed a way to deliver RNA in a capsule that can be swallowed, which they hope could help make people more receptive to them.

    In addition to making vaccines easier to tolerate, this approach could also be used to deliver other kinds of therapeutic RNA or DNA directly to the digestive tract, which could make it easier to treat gastrointestinal disorders such as ulcers.

    Nucleic acids, in particular RNA, can be extremely sensitive to degradation particularly in the digestive tract. Overcoming this challenge opens up multiple approaches to therapy, including potential vaccination through the oral route.

    In a new study, researchers showed that they could use the capsule they developed to deliver up to 150 micrograms of RNA—more than the amount used in mRNA COVID vaccines—in the stomach of pigs.

    part 1

  • Dr. Krishna Kumari Challa

    For several years, scientists have been developing novel ways to deliver drugs to the gastrointestinal tract. In 2019, the researchers designed a capsule that, after being swallowed, can place solid drugs, such as insulin, into the lining of the stomach.

    The pill, about the size of a blueberry, has a high, steep dome inspired by the leopard tortoise. Just as the tortoise is able to right itself if it rolls onto its back, the capsule is able to orient itself so that its contents can be injected into the lining of the stomach.

    In 2021, the researchers showed that they could use the capsule to deliver large molecules such as monoclonal antibodies in liquid form. Next, the researchers decided to try to use the capsule to deliver nucleic acids, which are also large molecules.

    Nucleic acids are susceptible to degradation when they enter the body, so they need to be carried by protective particles. For this study, the  team used a new type of polymeric nanoparticle  they had recently developed.

    These particles, which can deliver RNA with high efficiency, are made from a type of polymer called poly(beta-amino esters). The MIT team's previous work showed that branched versions of these polymers are more effective than linear polymers at protecting nucleic acids and getting them into cells. They also showed that using two of these polymers together is more effective than just one.

    Part 2

  • Dr. Krishna Kumari Challa

    To test the particles, the researchers first injected them into the stomachs of mice, without using the delivery capsule. The RNA that they delivered codes for a reporter protein that can be detected in tissue if cells successfully take up the RNA. The researchers found the reporter protein in the stomachs of the mice and also in the liver, suggesting that RNA had been taken up in other organs of the body and then carried to the liver, which filters the blood.

    Next, the researchers freeze-dried the RNA-nanoparticle complexes and packaged them into their drug delivery capsules. Working with scientists at Novo Nordisk, they were able to load about 50 micrograms of mRNA per capsule, and delivered three capsules into the stomachs of pigs, for a total of 150 micrograms of mRNA. This is the more than the amount of mRNA in the COVID vaccines now in use, which have 30 to 100 micrograms of mRNA.

    In the pig studies, the researchers found that the reporter protein was successfully produced by cells of the stomach, but they did not see it elsewhere in the body. In future work, they hope to increase RNA uptake in other organs by changing the composition of the nanoparticles or giving larger doses. However, it may also be possible to generate a strong immune response with delivery only to the stomach.

    "There are many immune cells in the gastrointestinal tract, and stimulating the immune system of the gastrointestinal tract is a known way of creating an immune response.

     Giovanni Traverso, Oral mRNA delivery using capsule-mediated gastrointestinal tissue injections, Matter (2022). DOI: 10.1016/j.matt.2021.12.022www.cell.com/matter/fulltext/S2590-2385(21)00680-9

    https://medicalxpress.com/news/2022-01-pill-rna-stomach-vaccines.ht...

    Part 3

    **

  • Dr. Krishna Kumari Challa

    How  Climate Change is Affecting Hibernation?

  • Dr. Krishna Kumari Challa

    Missing ear bone helps bats to echolocate

    Some bats have an anatomical quirk in their ears that could explain how they evolved to hunt in specialized ways, from sensing small fish to catching insects midflight. In 2015, researchers took 3D images of the inner ear of a bat skull but couldn’t find a feature shared by almost all mammals: a bony tube that connects the ear to the brain and encases nerve cells. A more thorough search revealed many more bat species in which this bony nerve channel was missing or poked with large holes. Researchers suspect the loss of this bony channel gave the bats new hearing capabilities because the nerves are less confined.

  • Dr. Krishna Kumari Challa

    Key growth factor protects gut from inflammatory bowel disease

    IBD, a disease category including ulcerative colitis and Crohn's disease, features chronic gut inflammation and many potential follow-on effects including arthritis and colorectal cancer.

     A growth factor protein produced by rare immune cells in the intestine can protect against the effects of inflammatory bowel disease (IBD), according to a new discovery. 

    In their study, published in Nature Immunology, the researchers found that the growth factor, HB-EGF, is produced in response to gut inflammation by a set of immune-regulating cells called ILC3s. These immune cells reside in many organs including the intestines, though their numbers are known to be depleted in the inflamed intestines of IBD patients.

    The researchers showed in experiments in mice that this growth factor can powerfully counter the harmful effects of a key driver of intestinal inflammation called TNF. In doing so, ILC3s protect gut-lining cells when they would otherwise die and cause a breach in the intestinal barrier. 

    Lei Zhou, Wenqing Zhou, Ann M. Joseph, Coco Chu, Gregory G. Putzel, Beibei Fang, Fei Teng, Mengze Lyu, Hiroshi Yano, Katrin I. Andreasson, Eisuke Mekada, Gerard Eberl, Gregory F. Sonnenberg. Group 3 innate lymphoid cells produce the growth factor HB-EGF to protect the intestine from TNF-mediated inflammationNature Immunology, 2022; DOI: 10.1038/s41590-021-01110-0

    https://researchnews.cc/news/11380/Key-growth-factor-protects-gut-f...

  • Dr. Krishna Kumari Challa

    Quantum leap on film

     In order to better understand (and possibly control) fast chemical reactions, it is necessary to study the behaviour of electrons as precisely as possible – in both space and time. However, up to now, microscopy methods have delivered only either spatially or temporally sharp images. By cleverly combining established techniques of tunnelling microscopy and laser spectroscopy, a team of researchers has now overcome these obstacles. Using their atomic quantum microscope, they can make the movement of electrons in individual molecules visible.

    It is essential not only for understanding biological processes (e.g. plant photosynthesis) to map the electron dynamics in molecules but also for many technical applications such as the development of solar cells or new types of electronic components. Until now, imaging methods have sometimes delivered images that are difficult to reproduce – or even contradictory. This is because they cannot map the fast electrons directly but rather must resort to techniques that can only reconstruct the behaviour of the electrons.

    Although modern microscopy techniques offer almost unlimited possibilities, certain compromises must be made. For example, scanning tunnelling microscopy with a resolution of one tenth of a picometre (1 × 10−12 m) allows extremely sharp images of individual atoms to be taken. However, this is slow and cannot capture the electron dynamics in a material. On the other hand, optical methods with ultra-fast laser pulses can detect electron movements in the attosecond (1 × 10−18 of a second) range. However, they can provide only coarse, washed-out spatial images – far removed from the atomic resolution possible with scanning tunnelling microscopes. The typical electron dynamics and laser pulses are in the range of a few hundred attoseconds.

    Part 1

  • Dr. Krishna Kumari Challa

    To do this, the researchers had to couple tried and tested scanning tunnelling microscopy with state-of-the-art laser technology. In a scanning tunnelling microscope, a wafer-thin, atomically thin tip travels just above a conductive surface. Thanks to the quantum-physical tunnel effect, electrons can flow between the surface and the microscope tip – even if there is no direct contact. For example, a molecule on a surface can gradually be shaved off atom by atom.

    The new microscopy technique uses laser pulses in order to modulate the tunnel current by selectively exciting the electrons in the material. “This must be done extremely quickly. Otherwise, thermal effects come into play and make the measurements impossible. 

    Thanks to the rapid development of laser technology in recent years, researchers have now been able to generate precisely the right pulses. Two years ago, Garg and Kern demonstrated the function of such an atomic quantum microscope for the first time.

    They have now been able to directly observe electron movement in molecules with this one-of-a-kind instrument. With the help of the ultra-short pulses, the electrons in the molecule can be excited to jump between the different orbitals. This was noticeable in the tunnel flow. The highlight of the new technique is being able to fire two minimally time-delayed pulses in quick succession at the molecule to be investigated with an exact time interval and scan it in the process. If this procedure is repeated several times and the time interval between the pulses varied, an image series that reproduces the behaviour of the electrons in this molecule with atomic accuracy is obtained. The fast laser pulses thus provide the information about the electron dynamics whilst the scanning tunnelling microscope precisely scans the molecule.

    This allowed the researchers to directly map the dynamics of electrons in molecules – how they jump from one orbital to another – for the first time. This basic technology provides completely new possibilities for directly observing quantum mechanical processes such as charge transfer in individual molecules and thus better understanding them. It is still not possible to predict the possible areas of application for such a quantum microscope. Especially in charge transfer processes, which play a crucial role in many biophysical reactions as well as in solar cells and transistors, it could provide crucial new insights.

    https://www.mpg.de/18173993/quantum-leap-electron-film

  • Dr. Krishna Kumari Challa

    Scientists discover link between high blood pressure and diabetes

    The long-standing enigma of why so many patients suffering with high blood pressure (known as hypertension) also have diabetes (high blood sugar) has finally been cracked by an international team of researchers.

    The important new discovery has shown that a small protein cell glucagon-like peptide-1 (GLP-1) couples the body's control of blood sugar and blood pressure.

    GLP-1 is released from the wall of the gut after eating and acts to stimulate insulin from the pancreas to control blood sugar levels. This was known but what has now been unearthed is that GLP-1 also stimulates a small sensory organ called the carotid body located in the neck. Locating the link required genetic profiling and multiple steps of validation. 

    The research group used an unbiased, high-throughput genomics technique called RNA sequencing to read all the messages of the expressed genes in the carotid body in rats with and without high BP. This led to the finding that the receptor that senses GLP-1 is located in the carotid body, but less so in hypertensive rats.

    The carotid body is the convergent point where GLP-1 acts to control both blood sugar and blood pressure simultaneously; this is coordinated by the nervous system which is instructed by the carotid body.

    People with hypertension and/or diabetes are at high risk of life-threatening cardiovascular disease. Even when receiving medication, a large number of patients will remain at high risk. This is because most medications only treat symptoms and not causes of high blood pressure and high sugar.

    It is known that blood pressure is notoriously difficult to control in patients with high blood sugar, so these findings are really important because by giving GLP-1 we might be able to reduce both sugar and pressure together, and these two factors are major contributors to cardiovascular risk.

    GLP1R attenuates sympathetic response to high glucose via carotid body inhibition, Circulation Research (2022). DOI: 10.1161/CIRCRESAHA.121.319874

    https://medicalxpress.com/news/2022-02-sweet-pressurescientists-lin...

  • Dr. Krishna Kumari Challa

    WHO warns of COVID medical waste threat

    The World Health Organization warned recently that the vast amount of waste produced in tackling the COVID-19 pandemic posed a threat to human and environmental health.

    The tens of thousands of tonnes of extra medical waste had put a huge strain on healthcare waste management systems, the WHO said in a report.

    The extra waste is "threatening human and environmental health and exposing a dire need to improve waste management practices", the UN health agency said.

    As countries scrambled to get personal protective equipment (PPE) to cope with the crisis, less attention was paid to disposing of COVID-19 health care waste safely and sustainably, the WHO said.

    The latest available data, from 2019, suggested that one in three healthcare facilities globally did not safely manage healthcare waste—and in the 46 least-developed countries, more than two in three facilities did not have a basic healthcare waste management service.

    "This potentially exposes health workers to needle stick injuries, burns and pathogenic microorganisms, while also impacting communities living near poorly-managed landfills and waste disposal sites through contaminated air from burning waste, poor water quality or disease-carrying pests," the WHO said.

    https://phys.org/news/2022-02-covid-medical-threat.html?utm_source=...

  • Dr. Krishna Kumari Challa

    World hits ten billion COVID vaccinations

    In little more than a year, ten billion doses of COVID-19 vaccines have been administered globally, in what has become the largest vaccination programme in history. Many nations began rolling out vaccines in late 2020 and early 2021. Since then, more than 60% of the world’s population — 4.8 billion people — is at least partially vaccinated with one of the more than 20 approved COVID-19 vaccines. “The world has never seen such rapid scale-up of a new life-saving technology,” says Amanda Glassman, with the Center for Global Development. But — as researchers warned last year when the first one billion doses had been administered — there are still huge inequities in access, with just 5.5% of people in low-income nations having received 2 doses.

    https://www.nature.com/articles/d41586-022-00285-2?utm_source=Natur...

  • Dr. Krishna Kumari Challa

  • Dr. Krishna Kumari Challa

    Flowers in The UK Are Blooming a Whole Month Earlier Than They Did in The 1980s

    For centuries, British flowers have been blooming like clockwork. A few months into spring, sometime around May or June, the nation bursts into color.

    Since the early 1980s, however, hundreds of plants have grown out of sync with the seasons, which means they're also unraveling from the complicated tapestry of interactions that keep ecosystems sustainably functioning.

    When analyzing the first blooms of 406 plant species from 1753 to 2019, researchers found a clear and worrisome shift.

    On average, flowers in the UK are blooming almost a whole month earlier than they were before 1986. In 2019, the first mean flowering date was as early as April 2.

    Obviously, not all plants bloom at the same time. Herbs and trees are the first to flower, sometime in mid-April. While shrubs take about a month longer to open up.

    The whole timeline, however, has been pushed forward as the climate changes.

    Today, human-caused global warming is progressing at a rapid and unprecedented rate, and it's impacting the very function of Earth's ecosystems.

    Something as dependable as the changing of the seasons is no longer so. 

    Early spring warming in the UK appears to be changing the amount of rain that falls and the snow that melts, and both of these factors are important when it comes to a budding flower.

    If temperatures continue to rise, the authors worry there will be a further shift in first flowering dates, possibly starting March or even earlier.

    This transition could lead some plants, including crops, to bud far too early, causing them to freeze or suffer frost damage.

    "We do not know whether adaptive evolution will allow populations to reach new [optimum flowering timing] rapidly enough to keep pace with climate change.

    Researchers fear these changes will lead to agricultural losses and extend the allergy season. But it's not just humans that will be impacted.

    "The timing of plant flowering can affect their pollination, especially when insect pollinators are themselves seasonal, and determine the timing of seed ripening and dispersal.

    Part 1

  • Dr. Krishna Kumari Challa

    Plant flowering also influences animals for which pollen, nectar, fruits and seeds are important resources… "

    The effects of an early flowering season could therefore ripple through ecosystems, causing what scientists call ecological (or phenological) mismatch – when the lifecycles of species that have evolved together and depend on each other fall out of sync.

    This can lead to disrupted migration patterns, species starvation, outbreaks of pests and disease, and even extinction.

    England isn't the only nation that has to worry about its flowering season. Earlier spring temperatures are being recorded throughout the world, both in the northern hemisphere and the southern hemisphere.

    Last year, in Japan, cherry blossoms bloomed the earliest they have in 1,200 years.

    Even with just a few centuries of data, however, the result of our emissions is clear to see. Climate change is winding up our Spring clock, and we don't know if we can wind it back again.

    https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2456

    Part 2

  • Dr. Krishna Kumari Challa

    Uranus And Neptune Aren't The Same Color. A New Study Could Finally Explain Why

    Uranus and Neptune are the most twin-like of all the planets in the Solar System. They are almost the same size and mass, have similar compositions and structures, even similar rotation rates.

    Which makes one glaring difference quite perplexing. Neptune is a fetching shade of azure, with visible swirling storms. Uranus is more of a featureless, delicate pale teal. If the two planets are so similar, whence the difference in their methane-based blues?

    New research, uploaded to preprint server arXiv and awaiting peer review, claims to have found an answer. According to a team led by planetary physicist Patrick Irwin of the University of Oxford in the UK, an extended layer of haze dilutes the hue of Uranus, resulting in a paler orb compared to its more distant twin; fraternal, not identical.

    Uranus and Neptune, according to our measurements of the two planets, are structured very similarly. A small, rocky core is surrounded by a mantle of water, ammonia, and methane ices; next, a gaseous atmosphere consisting primarily of hydrogen, helium and methane; and finally the upper atmosphere, including cloud tops. But that atmosphere isn't homogeneous; rather, it is thought to be layered, like every other atmosphere in the Solar System.

    Researchers analyzed visible and near-infrared observations of the two planets to generate new models of the atmospheric layers. They managed to find models that replicate the observations very well, including the storms on Neptune and the paler shade of Uranus.

    In their models, both planets have a layer of photochemical haze. This occurs when ultraviolet radiation from the Sun breaks down aerosol particles in the atmosphere, producing haze particles. It's a common process, seen on Venus, Earth, Saturn, Jupiter, dwarf planet Pluto, and moons Titan and Triton.

    The researchers called this the Aerosol-2 layer, and on both planets it seems to be a source of the cloud seeds that condense into methane ice at the lower boundary and snows deeper into the atmosphere. And on Uranus, this layer seems to be twice as opaque as it is on Neptune – and this is why the two planets look different.

    https://arxiv.org/abs/2201.04516

    https://www.sciencealert.com/we-might-finally-know-why-uranus-and-n...

  • Dr. Krishna Kumari Challa

    Almost No Coral Reefs in The World Will Be Safe at 1.5°C Warming, Scientists Warn

    Coral reefs have long been regarded as one of the earliest and most significant ecological casualties of global warming.

    In new research published in the journal PLOS Climate, we found that the future of these tropical ecosystems – thought to harbor more species than any other – is probably worse than anticipated.

    Climate change is causing more frequent marine heatwaves worldwide. Corals have adapted to live in a specific temperature range, so when ocean temperatures are too hot for a prolonged period, corals can bleach – losing the colorful algae that live within their tissue and nourish them via photosynthesis – and may eventually die.

    Across the tropics, mass bleaching and die-offs have gone from being rare to a somewhat regular occurrence as the climate has warmed. More frequent heatwaves mean that the time corals have to recover is getting shorter.

    In a 2018 report, the Intergovernmental Panel on Climate Change predicted that 1.5°C of global warming would cause between 70 and 90 percent of the world's coral reefs to disappear.

    Now, with models capable of examining temperature differences between coral reefs one kilometer apart, our team found that at 1.5°C of warming, which the world is predicted to reach in the early 2030s without drastic action to limit greenhouse gas emissions, 99 percent of the world's reefs will experience heatwaves that are too frequent for them to recover.

    That would spell catastrophe for the thousands of species that depend on coral reefs, as well as the roughly one billion people whose livelihoods and food supply benefits from coral reef biodiversity.

    Climate change is already degrading coral reefs globally. Now we know that protecting the last remaining temperature refuges will not work on its own. Slashing greenhouse gas emissions this decade is the best hope for saving what remains. The Conversation

    https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0...

    https://theconversation.com/safe-havens-for-coral-reefs-will-be-alm...

  • Dr. Krishna Kumari Challa

    World-Record 'Megaflash' of Lightning Stretched for Almost 500 Miles

    A jaw-dropping lightning megaflash that snaked across three states in the southern US just won a world record.

    A megaflash is not your standard cloud-to-ground lightning bolt. It's an enormous electric zigzag that travels from one electrified cloud to the next, almost instantaneously.

    https://www.sciencealert.com/space-images-show-700-km-lightning-meg...

  • Dr. Krishna Kumari Challa

    New insights about the toxicity of smoke produced by home stoves and power plants

    The color of smoke coming out from chimneys can vary greatly based on its source and how it is produced. For instance, small coal or biomass stoves typically release dense, black smoke, while power generation plants produce lighter-colored plumes of smoke.

    While these color differences are known to be linked to the different aerosols contained in smoke, so far not many studies have closely examined the major components of these aerosols and their effects on health. Researchers at Fudan University, Tsinghua University, and the Hong Kong Polytechnic University recently published a paper in Nature Energy outlining new interesting findings about the levels of toxicity of aerosols originating from different combustion sources, such as stoves in residential homes and coal-fired power plants (CFPPs).

    "Differences in the color of smoke coming out from distinct chimneys can indicate different aerosols in plumes. "A crucial question is, are the major components of aerosols from these emission sources different, and can they have different health impacts? To investigate this, we collected the aerosols from large scale CFPPs and common household stoves burning wood and coal."

    When researchers  analyzed the aerosols produced by CFPPs and common household stoves in the lab, they found that they had significant chemical differences. Interestingly, those emitted by household stoves primarily contained carbonaceous matter resulting from the incomplete combustion of coal or biomass material. On the other hand, large-scale powerplants that rely on efficient boilers could attain the complete combustion of fuels. This resulted in better pollution control metrics and a lower number of aerosols containing inorganic materials, such as transition and heavy metals.

    In the second part of their study, the researchers used real cells from human lungs (i.e., pulmonary cells) to determine the toxicity of the inhalable particulate matter (PM) produced by household stoves and CFPPs. They specifically examined the generation of intracellular reactive oxygen species (ROS) prompted by the PM, as well as cell viability and toxicity.

    Combining the chemical data with their previous information on chemical toxicity, they conducted a further aerosol toxic experiment with respiratory cells. In this experiment, they demonstrated that the toxicity of aerosols emitted from household coal/wood burning is more than 10 times higher than that from large scale coal-fired power plants.

    Di Wu et al, Toxic potency-adjusted control of air pollution for solid fuel combustion, Nature Energy (2022). DOI: 10.1038/s41560-021-00951-1

    https://techxplore.com/news/2022-02-insights-toxicity-home-stoves-p...

    **

  • Dr. Krishna Kumari Challa

    Scientists engineer new material that can absorb and release enormous amounts of energy

    A team of researchers  recently announced in the Proceedings of the National Academy of Sciences that they had engineered a new rubber-like solid substance that has surprising qualities. It can absorb and release very large quantities of energy. And it is programmable. Taken together, this new material holds great promise for a very wide array of applications, from enabling robots to have more power without using additional energy, to new helmets and protective materials that can dissipate energy much more quickly.

    A hypothetical rubber band is made out of a new metamaterial—a substance engineered to have a property not found in naturally occurring materials—that combines an elastic, rubber-like substance with tiny magnets embedded in it. This new "elasto-magnetic" material takes advantage of a physical property known as a phase shift to greatly amplify the amount of energy the material can release or absorb.

    A phase shift occurs when a material moves from one state to another: think of water turning into steam or liquid concrete hardening into a sidewalk. Whenever a material shifts its phase, energy is either released or absorbed. And phase shifts aren't just limited to changes between liquid, solid and gaseous states—a shift can occur from one solid phase to another. A phase shift that releases energy can be harnessed as a power source.

     Xudong Liang et al, Phase-transforming metamaterial with magnetic interactions, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2118161119

    https://phys.org/news/2022-02-scientists-material-absorb-enormous-a...

  • Dr. Krishna Kumari Challa

    How to find a planet you can’t see

  • Dr. Krishna Kumari Challa

    CAR-T cells hold cancer at bay

    A last-resort cancer treatment called CAR-T cell therapy has kept two people leukaemia-free for 12 years. “We can now conclude that CAR T cells can actually cure patients with leukaemia,” says physician and study author Carl June. CAR-T cell therapies involve removing immune cells called T cells from a person with cancer, and genetically altering them so that they produce proteins — called chimeric antigen receptors, or CARs — that recognize cancer cells. The cells are then reinfused into the person, in the hope that they will seek out and destroy tumours. But the therapy is expensive, risky and technically demanding, and doesn’t work for everyone.

    --

    First COVID human challenge trial

    Initial results from the first COVID-19 human challenge study show that healthy, young people developed no or mild symptoms. Such trials intentionally expose participants to a disease, providing a unique opportunity to study viral infections in detail from start to finish — but they are controversial because of the risks they pose to volunteers. The UK study of 34 individuals, aged 18–30, shows that such trials can be done safely, say scientists, and lays the groundwork for more in-depth studies of vaccines, antivirals and immune responses to SARS-CoV-2 infection.

    --

    Direct evidence of two types of water

    Water is unlike most other liquids on Earth: it has at least 66 weird properties, including high surface tension, high heat capacity, high melting and boiling points and low compressibility. Some chemists have come to think of it as not being one liquid at all, but two distinct liquid phases that coexist in a mixture. Now, physicists might have made the first direct observation of the transformation between the two ..., in supercold water mixed with trehalose, a natural antifreeze that keeps the liquid from freezing.

  • Dr. Krishna Kumari Challa

    There's a Bunch of Bacteria exchanging genetic material  in Your Gut, And It's Wilder Than We Thought

    The human gut is the host of a rampant microscopic orgy. To survive, the microbes in our digestive tract are having 'sex' with each other on a regular basis, all in the name of swapping secrets on how to survive deadly doses of antibiotics.

    A team of researchers from the University of Illinois at Urbana-Champaign and University of California Riverside has now learned just how far this bacterial bump-and-grind goes, finding exchanges that go beyond what we knew previously.

    Bacteria, of course, don't have genitals, but technically 'sex' in biology refers to any process that exchanges genetic material.

    By forming a 'temporary union' with another bacterium in our gut, a microbe can therefore transfer its genes to another – it doesn't even have to be the same species.

    All the microbe has to do is stick out a tube, called a pilus, and attach itself to another cell, shooting off a transferable package of DNA called a mobile genetic element when it's ready.

    The discovery of bacterial sex was made over 70 years ago, when scientists realized this horizontal gene transfer was how microbes were sharing resistance genes for certain antibiotics, thereby spreading antibiotic resistance.

    More recently, it's become clear that bacterial sex doesn't just occur when microbes are under attack. It happens all the time, and it's probably part of what keeps our microbiome fit and healthy.

    https://www.cell.com/cell-reports/fulltext/S2211-1247(21)01664-8?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2211124721016648%3Fshowall%3Dtrue

    https://www.sciencealert.com/there-are-a-bunch-of-bacteria-having-s...

  • Dr. Krishna Kumari Challa

    Three COVID-19 exposures needed for broad immunity

    The immune system develops a high-quality antibody response after three encounters with the coronavirus spike protein. These antibodies are also capable of neutralizing omicron efficiently. This applies to people who are triple-vaccinated, to those having recovered and then received two vaccinations and to double-vaccinated individuals who have experienced a breakthrough infection. These are results of a study which tracked the antibodies of vaccinated and recovered individuals for two years.

    Answers to the question how the immune systems can be "educated" to battle omicron and other immune escape variants of the virus are provided by a team of researchers. As they report in Nature Medicine, a total of three exposures to the viral spike protein leads to production of virus neutralizing antibodies not only in high quantity, but also high quality. These high-quality antibodies bind to the viral spike protein more vigorously and are also capable of effectively fighting the omicron variant. This applies to triple-vaccinated people, to people who have recovered from COVID-19 and then had two vaccinations, and to double-vaccinated people who then had a breakthrough infection.

    In the new study the team now defined several parameters in the blood of study participants: the concentration of antibodies to the viral spike protein, the binding strength of these antibodies, and their ability to neutralize infection of SARS-CoV-2 variants in cell culture. For estimating the extent of protective immunity, the latter two parameters are particularly important. The study revealed that the ability of the immune system to neutralize the virus correlates only weakly with the antibody titer. Rather, it was critical how effectively these antibodies bind to the virus and thus disable infection.

    As predicted from its many mutations, omicron exhibited the most pronounced evasion from neutralizing antibodies compared to all other viral variants tested. "For omicron, you need considerably more and better antibodies to prevent infection" . The researchers developed a new virus neutralization test, which allowed them to analyze antibodies in many serum samples and different variants of the virus at high throughput rates. A new finding of this study is that people require three separate exposures to the spike protein to build up high-level neutralizing activity against all viral variants, including omicron.

    As the scientists report, various constellations are possible for these three spike encounters. Triple-vaccinated people without prior SARS-CoV-2 infection had almost the same titer and quality of neutralizing antibodies against omicron as vaccinated convalescents or people who had a breakthrough infection with delta or omicron.

    In all cases, the neutralization activity reached similarly high levels and this was paralleled by an increased binding strength of the antibodies.

    Paul R. Wratil et al, Three exposures to the spike protein of SARS-CoV-2 by either infection or vaccination elicit superior neutralizing immunity to all variants of concern, Nature Medicine (2022). DOI: 10.1038/s41591-022-01715-4

    Nina Koerber et al, Dynamics of spike-and nucleocapsid specific immunity during long-term follow-up and vaccination of SARS-CoV-2 convalescents, Nature Communications (2022). DOI: 10.1038/s41467-021-27649-y

    https://researchnews.cc/news/11427/Three-COVID-19-exposures-needed-...

  • Dr. Krishna Kumari Challa

    Why water flows weirdly in nanotubes

    Normally, water flows faster through a wider pipe than a narrower one. But in tiny carbon nanotubes, the flow rate is flipped, with water moving faster through the narrowest channels. This week, the Nature Podcast features researchers who have come up with a new explanation for this phenomenon. The nanotubes are perfectly smooth, so there should be no friction of the classical kind. But there is still ‘quantum friction’ because of interactions between the atoms of water and carbon. There is less quantum friction in narrower tubes because of the way the layers of the tube walls are aligned, say the researchers.

  • Dr. Krishna Kumari Challa

    Mosquitoes are seeing red: These new findings about their vision could help you hide from these disease vectors

    Beating the bite of mosquitoes this spring and summer could hinge on your attire and your skin. New research indicates that a common mosquito species—after detecting a telltale gas that we exhale—flies toward specific colors, including red, orange, black and cyan. The mosquitoes ignore other colours, such as green, purple, blue and white. The researchers think these findings help explain how mosquitoes find hosts, since human skin, regardless of overall pigmentation, emits a strong red-orange "signal" to their eyes.

    Mosquitoes appear to use odours to help them distinguish what is nearby, like a host to bite. When they smell specific compounds, like CO2 from our breath, that scent stimulates the eyes to scan for specific colors and other visual patterns, which are associated with a potential host, and head to them.

    The results, published Feb. 4 in Nature Communications, reveal how the mosquito sense of smell—known as olfaction—influences how the mosquito responds to visual cues. Knowing which colours attract hungry mosquitoes, and which ones do not, can help design better repellants, traps and other methods to keep mosquitoes at bay.

    There are three major cues that attract mosquitoes: your breath, your sweat and the temperature of your skin. In this study, researchers found a fourth cue: the colour red, which can not only be found on your clothes, but is also found in everyone's skin. The shade of your skin doesn't matter, we are all giving off a strong red signature. Filtering out those attractive colours in our skin, or wearing clothes that avoid those colours, could be another way to prevent a mosquito biting.

    In the experiments conducted, without any odour stimulus, mosquitoes largely ignored a dot at the bottom of the chamber they were locked in, regardless of colour. After a spritz of CO2 into the chamber, mosquitos continued to ignore the dot if it was green, blue or purple in colour. But if the dot was red, orange, black or cyan, mosquitoes would fly toward it!

    The olfactory gating of visual preferences to human skin and visible spectra in mosquitoes, Nature Communications (2022). DOI: 10.1038/s41467-022-28195-x

    https://phys.org/news/2022-02-mosquitoes-red-vision-disease-vectors...

  • Dr. Krishna Kumari Challa

    Mind-blowing mission to the early Universe

    --
    Liquid Metal Magic: Hands free levitation and manipulation
  • Dr. Krishna Kumari Challa

    Your culture informs the emotions you feel when listening to music

    https://theconversation.com/how-your-culture-informs-the-emotions-y...

  • Dr. Krishna Kumari Challa

    Researchers report game-changing technology to remove 99% of carbon dioxide from air

    Researchers have demonstrated a way to effectively capture 99% of carbon dioxide from air using a novel electrochemical system powered by hydrogen.

    It is a significant advance for carbon dioxide capture and could bring more environmentally friendly fuel cells closer to market.

    Fuel cells work by converting fuel chemical energy directly into electricity. They can be used in transportation for things like hybrid or zero-emission vehicles.

    They found a way to embed the power source for the electrochemical technology inside the separation membrane. The approach involved internally short-circuiting the device.

    It's risky, but they managed to control this short-circuited fuel cell by hydrogen. And by using this internal electrically shorted membrane, they were able to get rid of the bulky components, such as bipolar plates, current collectors or any electrical wires typically found in a fuel cell stack.

    Now, the research team had an electrochemical device that looked like a normal filtration membrane made for separating out gases, but with the capability to continuously pick up minute amounts of carbon dioxide from the air like a more complicated electrochemical system.

    In effect, embedding the device's wires inside the membrane created a short-cut that made it easier for the carbon dioxide particles to travel from one side to the other. It also enabled the team to construct a compact, spiral module with a large surface area in a small volume. In other words, they now have a smaller package capable of filtering greater quantities of air at a time, making it both effective and cost-effective for fuel cell applications. Meanwhile, fewer components mean less cost, and more importantly, provide a way to easily scale up for the market.

    The research team's results showed that an electrochemical cell measuring 2 inches by 2 inches could continuously remove about 99% of the carbon dioxide found in air flowing at a rate of approximately two liters per minute. An early prototype spiral device about the size of a 12-ounce soda can is capable of filtering 10 liters of air per minute and scrubbing out 98% of the carbon dioxide, according to the researchers.

    Lin Shi et al, A shorted membrane electrochemical cell powered by hydrogen to remove CO2 from the air feed of hydroxide exchange membrane fuel cells, Nature Energy (2022). DOI: 10.1038/s41560-021-00969-5

    https://researchnews.cc/news/11453/Researchers-report-game-changing...

  • Dr. Krishna Kumari Challa

    A never-before-seen way bacteria infect cells

     A child is born into a world full of bacteria, starting with the birth process, where contact with the mother during vaginal birth introduces the infant to the first cultures, which are far different (and absent) during a Caesarian section. Nursing and breast-feeding provide additional early exposure to bacteria that will later contribute to the development of the immune system and influence the central nervous system.

    Bacteria can enter the body through an opening in your skin, such as a cut or a surgical wound, or through your airway and cause infections like bacterial pneumonia. They also enter and colonize in our gastrointestinal tract mainly by food sources. Bacteria that are in dirt, in milk and on plant surfaces enter our body.

    Bacteria are much larger than viruses, and they are too large to be taken up by receptor-mediated endocytosis. Cells engulf the larger objects and pull them in, which is generally called endocytosis. There are many different types of endocytosis, one of which is called phagocytosis.

     Biologists  have now identified a new way that one type of bacteria invades multiple cells within a living organism.

    The study, published this week in Nature Communications, describes how a new species of bacteria, Bordetella atropi, invades its roundworm host.

    And it is aptly named because the bacteria changes its shape into a long thread, growing up to 100 times the usual size of one bacterium in the span of 30 hours without dividing.

    By altering the genes of Bordetella atropi, the research team discovered that this invasive threading relies on the same genes and molecules that other bacteria use when they are in a nutrient-rich environment. However, these other bacteria only use this pathway to make subtly larger cells, whereas the B. atropi bacteria grows continuously.

    Other bacteria often transform into threads, called filamentation, in response to dangerous environments or damage to their DNA. This lets them continue to grow in size, but delay dividing into new bacterial cells until they fix the damage caused by the stress. 

    Here, however, the researchers were the first to observe filamentation as a way of spreading from cell to cell in a living organism for a purpose other than the stress response. They think that instead the new species is invading the host cells, detecting this rich environment and triggering filamentation in order to quickly infect more cells and access additional nutrients for their growth. 

    Although neither the bacteria nor the roundworm  infects humans, it is possible that the spreading mechanism may also be used by human pathogens. Separately, the nutrient-induced filamentation process might be used by other  bacteria to form biofilms, which can coat the tubing of catheters and lead to complications for patients.

    Tuan D. Tran et al, Bacterial filamentation as a mechanism for cell-to-cell spread within an animal host, Nature Communications (2022). DOI: 10.1038/s41467-022-28297-6

    https://phys.org/news/2022-02-never-before-seen-bacteria-infect-cel...

  • Dr. Krishna Kumari Challa

    New Discovery could help finetune immunity to fight infections, disease

    New Research  by scientists supports a novel theory that the innate immune system people are born with can respond differently to specific pathogens. This quality, known as immunological specificity, was previously ascribed only to the adaptive immune system, which develops over time through disease exposure.

    Published in the journal Cell Reports, the study suggests that this innate immune specificity is driven by the  nervous system and identifies a neuronal protein as a critical link in the process.

    Based on an animal model, these findings hold early promise for the treatment of conditions such as sepsis, arthritis and inflammatory bowel disease, in which the innate immune system attacks the body and causes uncontrolled inflammation. They could also provide the basis for finetuning an experimental treatment that harnesses the nervous system to fight infection.

    Clinical studies have shown that stimulating impaired neural circuits—either electrically or pharmacologically—can cure or alleviate many innate immune diseases. Knowing how the innate immune system generates a specific response to a particular pathogen enables us to manipulate neural circuits to adjust the intensity of the immune response as needed.

    This would essentially help restore balance to the immune system, either by dialing back an excessive response that can cause prolonged inflammation, tissue damage and even death; or by boosting an insufficient response to keep an infection from getting worse. 

    Jingru Sun, Neuronal GPCR NMUR-1 regulates distinct immune responses to different pathogens, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.110321www.cell.com/cell-reports/full … 2211-1247(22)00032-8

    https://medicalxpress.com/news/2022-02-discovery-finetune-immunity-...

  • Dr. Krishna Kumari Challa

    New implant offers promise for the paralyzed

  • Dr. Krishna Kumari Challa

    Mysterious Link Between Vitamin D And COVID-19 Reaffirmed in 'Striking' New Findings

    Scientists found "striking" differences in the chances of getting seriously ill from COVID-19 when they compared patients who had sufficient vitamin D levels prior to contracting the disease, with those who didn't.

    A study published recently  in research journal PLOS One found that about half of people who were vitamin D deficient before getting COVID-19 developed severe illness, compared to less than 10 percent of people who had sufficient levels of the vitamin in their blood.

    We know vitamin D is vital for bone health, but its role in protecting against severe COVID-19 is less-well established. 

    The latest research was the first to examine vitamin D levels in individuals prior to them contracting COVID-19, the study authors said.

    The findings suggested vitamin D helped bolster the immune system to deal with viruses that attack the respiratory system.

    https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

    **

  • Dr. Krishna Kumari Challa

    As seed-hauling animals decline, some plants can’t keep up with climate change

  • Dr. Krishna Kumari Challa

     

    Happy women scientists day!

    The United Nations General Assembly declared 11 February as the International Day of Women and Girls in Science in 2015.

  • Dr. Krishna Kumari Challa

    Just 14 cases: Guinea worm disease nears eradication

  • Dr. Krishna Kumari Challa

    Less powerful black hole blows environment clean 

    Until now, astronomers have always assumed that only blackholes with strong radiation stop star formation from within the galaxy. This is because these black holes blow away gas, which is the building block for stars. The question, however, is whether galaxies without strongly radiating black holes are also inhibited in their growth.

    An international team of astronomers has discovered that even a weak jet stream from a low-active black hole can be a kind of leaf blower to clean parts of a galaxy. The observed black hole removes about 75% of the cold gas in the central regions of the galaxy in a few million years. This probably stops the formation of stars. The researchers publish their findings on Thursday in the journal Nature Astronomy.

    This low-power black hole is found in the galaxy B2 0258+35 in the constellation of Perseus. It does not emit strong radiation but has radio plasma jets that are bright, as opposed to black holes that emit visible light, ultraviolet or X-rays.

    The gas at B2 0258+35 is blown away steadily at a speed of about 500 kilometers per second. It is roughly five to ten solar masses per year and takes a few million years. The gas is not moving fast enough to escape from the reach of the galaxy. It eventually falls back and ends up at the edges of the galaxy. From there, it cannot properly form new stars.

    Suma Murthy, Cold gas removal from the centre of a galaxy by a low-luminosity jet, Nature Astronomy (2022). DOI: 10.1038/s41550-021-01596-6www.nature.com/articles/s41550-021-01596-6

    https://phys.org/news/2022-02-powerful-black-hole-environment.html?...

  • Dr. Krishna Kumari Challa

    Making installed train windows permeable to mobile-phone signals

  • Dr. Krishna Kumari Challa

    The chronic growing pains of communicating science online

    https://www.science.org/doi/10.1126/science.abo0668

  • Dr. Krishna Kumari Challa

    Lifetime of knowledge can clutter memories of older adults, researchers suggest

    When a person tries to access a memory, their brain quickly sifts through everything stored in it to find the relevant information. But as we age, many of us have difficulty retrieving memories. In a review publishing in the journal Trends in Cognitive Sciences on February 11, researchers propose an explanation for why this might be happening: the brains of older adults allocate more space to accumulated knowledge and have more material to navigate when attempting to access memories. While this wealth of prior knowledge can make memory retrieval challenging, the researchers say it has its upsides—this life experience can aid with creativity and decision-making.

    Researchers looked at several behavioral and neuroimaging studies, which show that older adults have difficulty suppressing information that is no longer relevant and that when searching for a specific memory, they often retrieve other, irrelevant memories along with it. The studies also showed that when given a cognitive task, older adults rely more heavily on previous knowledge than younger adults do.

    While the researchers focus primarily on the difficulties that these cluttered memories may pose, they also highlight a few situations in which these crowded memoryscapes may be useful. "Evidence suggests that older adults show preserved, and at times enhanced, creativity as a function of enriched memories," the researchers write. They further hypothesize that older adults may be well served by their prior knowledge when it comes to decision-making, where they can pull on their accumulated wisdom.

    With continued study and increased understanding of how memory works in older adults, researchers are hopeful that they may be able to find new ways to help them. It is possible that the increased binding and richer encodings of older adults can even be leveraged to improve older adults' learning and memory.

    Trends in Cognitive Sciences, Amer: "Cluttered memory representations shape cognition in old age" www.cell.com/trends/cognitive- … 1364-6613(21)00310-7 , DOI: 10.1016/j.tics.2021.12.002

    https://medicalxpress.com/news/2022-02-lifetime-knowledge-clutter-m...

  • Dr. Krishna Kumari Challa

    Space weather took out 40 SpaceX satellites, and it could get worse

    SpaceX can mitigate the risk to its satellites my monitoring space weather in real time, but an increasingly active Sun and the large number of satellites in orbit won’t make it easy!

    SpaceX just lost 40 of its newest satellites to a geomagnetic storm caused by solar radiation, a hazard that will only increase for Elon Musk’s company and other satellite operators over the coming few years.

    SpaceX launched its latest batch of 49 Starlink satellites on 3 February, the latest in a constellation of more than 1900 small satellites providing broadband internet connectivity from low Earth orbit. On 4 February, a mass of charged particles ejected from the sun in late January reached Earth, dumping their energy into the planet’s magnetic field and increasing the density of the upper atmosphere.

    Satellites launched into low Earth orbit always contend with some amount of atmospheric drag, but in a statement released 8 February, SpaceX noted the drag produced by the geomagnetic storm was 50% higher than in earlier launches. The company acknowledged that the drag was too much for 40 of the 49 satellites, which have reentered or will soon reenter the Earth’s atmosphere.

  • Dr. Krishna Kumari Challa

    Reusable plastic bottles shown to release hundreds of chemicals

    Researchers  have found several hundred different chemical substances in tap water stored in reusable plastic bottles. Several of these substances are potentially harmful to human health. There is a need for better regulation and manufacturing standards for manufacturers, according to the chemists behind the study.

    Have you ever experienced the strange taste of water after it has been in a reusable plastic bottle for a while? It appears that there is a solid, yet worrying reason for this.

    Chemists  have studied which chemical substances are released into liquids by popular types of soft plastic reusable bottles. The results were quite a surprise.

    The researchers were taken aback by the large amount of chemical substances they found in water after 24 hours in the bottles. There were hundreds of substances in the water—including substances never before found in plastic, as well as substances that are potentially harmful to health. After a dishwasher cycle, there were several thousand.

    They  detected more than 400 different substances from the bottle plastic and over 3,500 substances derived from dishwasher soap. A large portion of these are unknown substances that the researchers have yet to identify. But even of the identified chemicals, the toxicity of at least 70 % remains unknown.

    Photo-initiators are among the toxic substances in the water which worry the researchers. These are known to have potentially harmful effects on health in organisms, such as being endocrine disruptors and carcinogens. Furthermore, the researchers found a variety of plastic softeners, antioxidants and release agents used in the manufacture of the plastic, as well as Diethyltoluamide (DEET), commonly known as the active substance in mosquito spray.

    Machine washing adds more substances into the bottled water
    In their experiments, the researchers mimicked the ways in which many people typically use plastic drinks bottles. People often drink water that has been kept in bottles for several hours. The researchers left ordinary tap water in both new and used drinking bottles for 24 hours, both before and after machine washing, as well as after the bottles had been in the dishwasher and rinsed thoroughly in tap water.

    What is released most after machine washing are the soap substances from the surface. Most of the chemicals that come from the water bottle itself remain after machine washing and extra rinsing. The most toxic substances that we identified actually came after the bottle had been in the dishwasher—presumably because washing wears down the plastic and thereby increases leaching. In new reusable bottles, close to 500 different substances remained in the water after an additional rinse. Over 100 of these substances came from the plastic itself.

    Just because these substances are in the water, doesn't mean that the water is toxic and affects us humans. But the problem is, is that we just don't know. And in principle, it isn't all that great to be drinking soap residues or other chemicals.

    Part1

  • Dr. Krishna Kumari Challa

    The researchers suspect that bottle manufacturers only add a small proportion of the substances found intentionally. The majority have inadvertently occurred either during the production process or during use, where substances may have been converted from other substances. This includes the presence of the mosquito repellent DEET, where the researchers hypothesize that as one of the plastic softeners degrades, it is converted into DEET.

    But even of the known substances that manufacturers deliberately add, only a tiny fraction of the toxicity has been studied. So, as a consumer, you don't know if any of the others have a detrimental effect on your health.

    The study results were published in the Journal of Hazardous Materials.

    1. Selina Tisler, Jan H. Christensen. Non-target screening for the identification of migrating compounds from reusable plastic bottles into drinking water. Journal of Hazardous Materials, 2022; 429: 128331 DOI: 10.1016/j.jhazmat.2022.128331

    https://researchnews.cc/news/11590/Reusable-plastic-bottles-shown-t...

    Part2

  • Dr. Krishna Kumari Challa

    Blood clot testing using smartphones

  • Dr. Krishna Kumari Challa

    Two Simple Muscle Exercises Can Help Reduce Dizziness When Standing Up

    Feeling dizzy or light-headed when standing is a common experience caused by a drop in blood pressure. When this blood pressure dip is very brief and rapid, and not tied to any other health problems, it's referred to as initial orthostatic hypotension or IOH.

    New research suggests some simple muscle exercises before or after standing could limit the effects of IOH, bringing relief to those who experience it, with no cost and no drugs involved. The key, it seems, is activating the lower body muscles before or after standing.

    While researchers tested the muscle-tensing idea before – after people already stood up – with some success, this new study looked at whether it could work as a pre-emptive measure.

    These are simple, effective, and cost-free interventions that patients can use to prevent their symptoms from IOH

    The study involved 22 young women with a history of IOH, and two exercises were tested: repeatedly raising the knees while sitting for 30 seconds before standing and crossing the legs for 30 seconds after standing.

    Researchers monitored the participants' heart rate and blood pressure during the experiments, with intervals between each one. Participants were also asked to self-report on the symptoms of IOH, including feelings of dizziness.

    Compared with no intervention measures – so simply standing up as normal – both exercises made a significant difference in limiting the temporary drop in blood pressure and relieving the symptoms of IOH.

    Since it is a physical maneuver, it simply requires the lower body limbs, which patients can utilize at any time and from anywhere to combat their symptoms