Despite that, the Indian recommendation still works out to a wide range across moderate and severe categories — from a low of about 35 mg to a high of 140 mg (for a 70kg person). This is in sharp contrast to the 32mg (total daily dose) recommendation in the US.
Indian government spokespersonshave attributed the rise in fungal infections to the fact doctors in the country may have irrationally used steroids.
But given the government’s own guidelines for steroid use are so much higher than in other countries, there should be analysis into whether this may be contributing to the significant rise in fungal infections (3).
Those findings would have profound implications on India’s pandemic management.
A framework to simulate the same physics using two different Hamiltonians
Researchers have recently been investigating situations in which two distinct Hamiltonians could be used to simulate the same physical phenomena. A Hamiltonian is a function or model used to describe a dynamic system, such as the motion of particles.
In a paper published in Physical Review Letters, researchers introduced a framework that could prove useful for simulating the same physics with two distinct Hamiltonians. In addition, they provide an example of an analog simulation and show how one could build an alternative version of a digital quantum simulator.
Their result indicates that using the same Hamiltonian is not always a necessary condition. As an example, they showed that the physics of one-axis twisting can be simulated by a spin chain with an external field, even though the one-axis twisting model has infinite range interactions and this spin chain model has only nearest-neighboring interactions. The Hamiltonian of these two models are physically different, i.e. having different energy spectra, but still one can simulate the one with the other if the dynamics starts with special states.
A new material made from carbon nanotubes can generate electricity by scavenging energy from its environment
Engineers have discovered a new way of generating electricity using tiny carbon particles that can create a current simply by interacting with liquid surrounding them.
The liquid, anorganic solvent, draws electrons out of the particles, generating a current that could be used to drivechemical reactionsor to power micro- or nanoscale robots, the researchers say.
"This mechanism is new, and this way of generatingenergyis completely new.
When a carbon nanotube is coated with layer of fuel, moving pulses of heat, or thermopower waves, travel along the tube, creating an electrical current.
This technology is intriguing because all you have to do is flow a solvent through a bed of these particles. This allows you to do electrochemistry, but with no wires.
In a new study describing this phenomenon, the researchers showed that they could use this electric current to drive a reaction known as alcohol oxidation—an organic chemical reaction that is important in the chemical industry.
Albert Tianxiang Liu et al, Solvent-induced electrochemistry at an electrically asymmetric carbon Janus particle, Nature Communications (2021). DOI: 10.1038/s41467-021-23038-7
Physicists report definitive evidence how auroras are created
The aurora borealis, or northern lights, that fill the sky in high-latitude regions have fascinated people for thousands of years. But how they're created, while theorized, had not been conclusively proven till recently.
In a new study, a team of physicists reports definitive evidence that the most brilliant auroras are produced by powerful electromagnetic waves during geomagnetic storms. The phenomena, known as Alfven waves, accelerate electrons toward Earth, causing the particles to produce the familiar atmospheric light show.
The study, published online June 7 in the journalNature Communications, concludes a decades-long quest to demonstrate experimentally the physical mechanisms for the acceleration of electrons by Alfven waves under conditions corresponding to Earth's auroral magnetosphere.
Measurements revealed this small population of electrons undergoes 'resonant acceleration' by the Alfven wave's electric field, similar to a surfer catching a wave and being continually accelerated as the surfer moves along with the wave.
Scientists have known that energized particles that emanate from the sun—such as electrons racing at approximately 45 million miles per hour—precipitate along the Earth'smagnetic field linesinto the upper atmosphere, where they collide with oxygen and nitrogen molecules, kicking them into an excited state. These excited molecules relax by emitting light, producing the colorful hues of the aurora.
The theory was supported by spacecraft missions that frequently found Alfven waves traveling Earthward above auroras, presumably accelerating electrons along the way. Although space-based measurements had supported the theory, limitations inherent to spacecraft and rocket measurements had prevented a definitive test.
The physicists were able to find confirmatory evidence in a series of experiments conducted at the Large Plasma Device (LPD) in UCLA's Basic Plasma Science Facility, a national collaborative research facility supported jointly by the U.S. Department of Energy and National Science Foundation.
Turning off lights can save migrating birds from crashing into buildings
Every night during the spring and fall migration seasons, thousands of birds are killed when they crash into illuminated windows, disoriented by the light. But a new study in PNAS shows that darkening just half of a building's windows can make a big difference for birds. Using decades' worth of data and birds collected by Field Museum scientists at Chicago's McCormick Place convention center, the researchers found that on nights when half the windows were darkened, there were 11 times fewer bird collisions during spring migration and 6 times fewer collisions during fall migration than when all the windows were lit.
This research provides the best evidence yet that migrating birds are attracted to building lights, often causing them to collide with windows and die. And that turning off the lights can save the birds.
Bacteriophages prove to be more effective at fighting antibiotic resistance when trained
The threat of antibiotic resistance rises as bacteria continue to evolve to foil even the most powerful modern drug treatments. By 2050, antibiotic resistant-bacteria threaten to claim more than 10 million lives as existing therapies prove ineffective.
Bacteriophage, or "phage," have become a new source of hope against growingantibiotic resistance. Ignored for decades bywestern science, phages have become the subject of increasing research attention due to their capability to infect and kill bacterial threats.
A new project has provided evidence that phages that undergo special evolutionary training increase their capacity to subduebacteria. Like a boxer in training ahead of a title bout, pre-trained phages demonstrated they could delay the onset of bacterial resistance.
The trained phage had already experienced ways that the bacteria would try to dodge it. It had 'learned' in a genetic sense. It had already evolved mutations to help it counteract those moves that the bacteria were taking. Scientists are using phage's own improvement algorithm, evolution by natural selection, to regain its therapeutic potential and solve the problem of bacteria evolving resistance to yet another therapy.
The researchers are now extending their findings to research how pre-trained phages perform on bacteria important in clinical settings, such as E. coli. They are also working to evaluate how well training methods work in animal models.
Joshua M. Borin et al, Coevolutionary phage training leads to greater bacterial suppression and delays the evolution of phage resistance, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2104592118
Cancer patients who are undergoing targeted therapy can look forward to a new blood test that could tell their doctors whether the treatment is working, within one day after the start of the treatment. This will significantly speed up the evaluation process and enable doctors to make adjustments to the treatment plan, if necessary, to improve patients' chances of recovery.
Sijun Pan et al, Extracellular vesicle drug occupancy enables real-time monitoring of targeted cancer therapy, Nature Nanotechnology (2021). DOI: 10.1038/s41565-021-00872-w
More than 65% of inhaled coronavirus particles reach the deepest region of our lungs where damage to cells can lead to low blood oxygen levels, new research has discovered, and more of these aerosols reach the right lung than the left.
For more than 25 years, Burmese pythons have been living and breeding in the Florida Everglades, where they prey on native wildlife and disrupt the region's delicate ecosystems. A new study shows that infrared cameras could make it easier to spot these invasive snakes in the Florida foliage, providing a new tool in the effort to remove them.
Studies reveal skull as unexpected source of brain immunity
he immune system is the brain’s best frenemy. It protects the brain from infection and helps injured tissues heal, but it also causes autoimmune diseases and creates inflammation that drives neurodegeneration.
Two new studies in mice suggest that the double-edged nature of the relationship between the immune system and the brain may come down to the origins of the immune cells that patrol the meninges, the tissues that surround the brain and spinal cord. In complementary studies published June 3 in the journal Science, two teams of researchers unexpectedly found that many of the immune cells in the meninges come from bone marrow in the skull and migrate to the brain through special channels without passing through the blood.
These skull-derived immune cells are peacekeepers, dedicated to maintaining a healthy status quo. It’s the other immune cells, the ones that arrive from the bloodstream, that seem to be the troublemakers. They carry genetic signatures that mark them as likely to promote autoimmunity and inflammation, and they become more abundant with aging or under conditions of disease or injury. Taken together, the findings reveal a key aspect of the connection between the brain and the immune system that could inform our understanding of a wide range of brain disorders.
Andrea Cugurra, Tornike Mamuladze, Justin Rustenhoven, Taitea Dykstra, Giorgi Beroshvili, Zev J. Greenberg, Wendy Baker, Zach Papadopoulos, Antoine Drieu, Susan Blackburn, Mitsuhiro Kanamori, Simone Brioschi, Jasmin Herz, Laura G. Schuettpelz, Marco Colonna, Igor Smirnov, Jonathan Kipnis.Skull and vertebral bone marrow are myeloid cell reservoirs for the meninges and CNS parenchyma.Science, 2021; eabf7844 DOI:10.1126/science.abf7844
Defying body clock linked to depression and lower wellbeing
People whose sleep pattern goes against their natural body clock are more likely to have depression and lower levels of wellbeing, according to a largescale new study.
This research also found the most robust evidence to date that being genetically programmed to be an early riser is protective against major depression, and improves wellbeing. Researchers suggest this may be because society is set up to be more aligned to early risers, through the standard 9-5 working pattern.
Sea level rise isn't the only way climate change will devastate the coast. Our research, published today, found it is also making waves more powerful, particularly in the Southern Hemisphere.
Scientists can predict which women will have serious pregnancy complications
Women who will develop potentially life-threatening disorders during pregnancy can be identified early when hormone levels in the placenta are tested, a new study has shown.
Pregnancy disorders affect around one in tenpregnant women. Nearly all of the organ systems of the mother's body need to alter their function during pregnancy so that the baby can grow. If the mother's body cannot properly adapt to the growing baby this leads to major and common issues including fetal growth restriction, fetal over-growth,gestational diabetes, and preeclampsia—a life-threateninghigh blood pressurein the mother.
Many of these complications lead to difficult labors forwomenwith more medical intervention and lifelong issues for the baby including diabetes, heart issues and obesity.
Pregnancy disorders are usually diagnosed during the second or third trimester of gestation when they have often already had a serious impact on the health of the mother and baby. The current methods to diagnose pregnancy disorders are not sensitive or reliable enough to identify all at risk pregnancies.
Now scientists have found a way to test hormone levelsin the placenta to predict which women will have serious pregnancy complications.
This study found hormonal biomarkers from the placenta could indicate which women would have pregnancy complications. We found that these biomarkers are present from the first trimester of pregnancy, normally women are only diagnosed with complications during the second or third trimester when disorders may already have had serious consequences for the health of the mother and her developing baby.
Subatomic particle seen changing to antiparticle and back
Physicists have proved that a subatomic particle can switch into its antiparticle alter-ego and back again, in a new discovery revealed recently.
The extraordinarily precise measurement was made by UK researchers using the Large Hadron Collider beauty (LHCb) experiment at CERN.
It has provided the first evidence that charmmesons can change into their antiparticle and back again.
For more than 10 years, scientists have known that charm mesons,subatomic particlesthat contain a quark and an antiquark, can travel as a mixture of their particle and antiparticle states.
It is a phenomenon called mixing.
However, this new result shows for the first time that they can oscillate between the two states.
Armed with this new evidence, scientists can try to tackle some of the biggest questions in physics around how particles behave outside of the Standard Model.
One being, whether these transitions are caused by unknown particles not predicted by the guiding theory.
The research, submitted toPhysical Review Lettersand available on arXiv.
Observation of the mass difference between neutral charm-meson eigenstates. arXiv:2106.03744v1 [hep-ex] arxiv.org/abs/2106.03744
Slow-moving arctic soils form patterns that, from a distance, resemble those found in common fluids such as drips in paint and birthday cake icing. Los Alamos researchers and their collaborators analyzed existing arctic soil formations and compared them to viscous fluids, determining that there is a physical explanation for this pattern that is common to both Earth and Mars landscapes.
Potentially lethal marine algae blooms have not increased in number over the last three decades, but pose a serious threat to aquaculture, according to a UN global assessment released recently.
Small pieces of plastic are everywhere, stretching from urban environments to pristine wilderness. Left to their own devices, it can take hundreds of years for them to degrade completely. Catalysts activated by sunlight could speed up the process, but getting these compounds to interact with microplastics is difficult. In a proof-of-concept study, researchers reporting in ACS Applied Materials & Interfaces developed self-propelled microrobots that can swim, attach to plastics and break them down.
The World Health Organization and the Centers for Disease Control recommend keeping a certain distance between people to prevent the spread of COVID-19. These social distancing recommendations are estimated from a variety of studies, but further research about the precise mechanism of virus transport from one person to another is still needed.
This "cloud avalanche" occurred near the Kapuche Glacier Lake in the mountains of Nepal last month. At that time, a group of travel companions were camping by the lake, and they took the risk of taking pictures of this rare visual feast. The white snow clouds rushed down the valley, unstoppable, instantly swallowing the mountains and hitting the lake surface. Against the backdrop of the blue sky and the yellow-brown mountains, they were more distinct, magnificent and shocking. The strong air flow overturned the tents and sleeping bags, frightening the travellers, but fortunately no casualties were reported. After that, a small rainbow appeared by the lake, which was extremely beautiful, and the travelers all cheered and marveled at it. Call it "perfect cloud collapse".
Bacteria-sized robots take on microplastics and win by breaking them down
Small pieces of plastic are everywhere, stretching from urban environments to pristine wilderness. Left to their own devices, it can take hundreds of years for them to degrade completely. Catalysts activated by sunlight could speed up the process, but getting these compounds to interact with microplastics is difficult. In a proof-of-concept study, researchers reporting in ACS Applied Materials & Interfaces developed self-propelled microrobots that can swim, attach to plastics and break them down.
While plastic products are omnipresent indoors, plastic waste and broken bits now litter the outdoors, too. The smallest of these—microplastics less than 5 mm in size—are hard to pick up and remove. In addition, they can adsorb heavy metals and pollutants, potentially harming humans or animals if accidently consumed. So, previous researchers proposed a low-energy way to get rid of plastics in the environment by using catalysts that use sunlight to produce highly reactive compounds that break down these types of polymers. However, getting the catalysts and tiny plastic pieces in contact with each other is challenging and usually requires pretreatments or bulky mechanical stirrers, which aren't easily scaled-up. so wanted to create a sunlight-propelled catalyst that moves toward and latches onto microparticles and dismantles them.
To transform a catalytic material into light-driven microrobots, the researchers made star-shaped particles of bismuth vanadate and then evenly coated the 4–8 µm-wide structures with magnetic iron oxide. The microrobots could swim down a maze of channels and interact with microplastic pieces along their entire lengths. The researchers found that under visible light, microrobots strongly glommed on to four common types of plastics. The team then illuminated pieces of the four plastics covered with the microrobot catalyst for seven days in a dilute hydrogen peroxide solution. They observed that the plastic lost 3% of its weight and that the surface texture for all types changed from smooth to pitted, and small molecules and components of the plastics were found in the left-over solution. The researchers say the self-propelled microrobot catalysts pave the way toward systems that can capture and degrade microplastics in hard-to-reach-locations.
Seyyed Mohsen Beladi-Mousavi et al, A Maze in Plastic Wastes: Autonomous Motile Photocatalytic Microrobots against Microplastics, ACS Applied Materials & Interfaces (2021). DOI: 10.1021/acsami.1c04559
Researchers create quantum microscope that can see the impossible
In a major scientific leap, researchers have created a quantum microscope that can reveal biological structures that would otherwise be impossible to see.
This paves the way for applications in biotechnology, and could extend far beyond this into areas ranging from navigation to medical imaging.
The microscopeis powered by the science of quantum entanglement, an effect Einstein described as "spooky interactions at a distance".
The quantum entanglementin this microscope provides 35 percent improved clarity without destroying the cell, allowing us to see minute biological structures that would otherwise be invisible.
"The benefits are obvious—from a better understanding of living systems, to improved diagnostic technologies.
Scientists Have Calculated The Weight of All The SARS-CoV-2 in The World
If all the SARS-CoV-2 particles currently circulating in humans around the globe were gathered together into one place, they would weigh somewhere between the weight of an apple and that of a young toddler, according to a new study.
A group of researchers recently calculated that each infected individual carries about 10 billion to 100 billion individual SARS-CoV-2 particles at the peak of their infection. That suggests that all of the SARS-CoV-2 viruses currently infecting people around the world — which has been about 1 million to 10 million infections at any given time during the course of the pandemic — have a collective mass of somewhere between 0.22 and 22 pounds (0.1 and 10 kilograms).
Small doesn't mean insignificant, however.
Here we are talking about a super-tiny mass of viruses, and they are completely wreaking havoc on the world.
'Vegan spider silk' provides sustainable alternative to single-use plastics
Researchers have created a plant-based, sustainable, scalable material that could replace single-use plastics in many consumer products.
The researchers, from the University of Cambridge, created a polymer film by mimicking the properties of spider silk, one of the strongest materials in nature. The new material is as strong as many common plastics in use today and could replace plastic in many common household products.
The material was created using a new approach for assemblingplant proteinsinto materials which mimic silk on a molecular level. The energy-efficient method, which uses sustainable ingredients, results in a plastic-like free-standing film, which can be made at industrial scale. Non-fading 'structural' color can be added to the polymer, and it can also be used to make water-resistant coatings.
The material is home compostable, whereas other types of bioplastics require industrial composting facilities to degrade.
Ever since scientists discovered cells under the microscope more than 350 years ago, they have noted that each type of cell has a characteristic size. From tiny bacteria to inches-long neurons, size matters for how cells work. The question of how these building blocks of life regulate their own size, however, has remained a mystery.
Now we have an explanation for this long-standing biological question. In a study focusing on the growing tip of plants, researchers show that cells use their DNA content as an internal gauge to assess and adjust their size.
Hydrogen sulfide critical to innate ability of bacteria to survive antibiotics
The signaling molecule hydrogen sulfide (H2S) plays a critical role in antibiotic tolerance, the innate ability of bacteria to survive normally lethal levels of antibiotics, a new study finds.
the study revolves around tolerance, wherein bacteria in general have evolved to use common defense systems to resistantibiotics. Tolerance differs from antibiotic resistance, where one species happens to acquire a genetic change that helps them resist treatment.
In one defense mechanism, tolerant bacteria, also called "persisters," stop multiplying (proliferating), reducing their energy use (metabolism) to survive antibiotic treatment, but resuming growth when the treatment ends. Persisters are particularly abundant in biofilms,bacterial coloniesthat live in tough polymeric matrices which further prevent their eradication.
The combined trends toward resistant infections and fewer new antimicrobials are projected to kill 10 million people annually by the year 2050. New approaches are urgently needed to prevent this, and this study suggests that suppressing bacterial H2S would make different antibiotics more potent.
In a breakthrough in metamaterials, for the first time in the world, researchers at Tel Aviv University have developed an innovative nanotechnology that transforms a transparent calcite nanoparticle into a sparkling gold-like particle. In other words, they turned the transparent particle into a particle that is visible despite its very small dimensions. According to the researchers the new material can serve as a platform for innovative cancer treatments.
Biodegradable microspheres can be used to deliver heart cells generated from stem cells to repair damaged hearts after a heart attack, according to new findings by UCL researchers. This type of cell therapy could one day cure debilitating heart failure, which affects an estimated 920,000 people in the UK and continues to rise as more people are surviving a heart attack than ever before.
Nepal's unique lightning signature involves up to four strikes per flash
While every lightning flash is unique in the way the discharge travels through the atmosphere, whether cloud-to-cloud, cloud-to-ground or the more esoteric sprites, halos, jets, and elves of the upper atmosphere. There are common features in these different types of lightning and for cloud-to-ground flashes, it has been assumed that there are two main types of flash known to meteorologists and atmospheric scientists—negative ground flashes and positive ground flashes.
The difference between the negative and positive flash is simply that the polarity of the discharge reaching the ground in the lightning flash. Most (90 percent) cloud-to-ground flashes are negative ground flashes. Just 10 percent are positive. The positive ground flash involves a single stroke.
A novel phenomenon has been found in the sub-tropical, mountainous region of Nepal now.
Researchers have used a simple circuit and antenna system to measure the electrical signature of lightning flashes in the Himalayan region and found that positive ground flashes there are unique. Instead of involving a single strike, lightning here involves up to four strikes per flash, or discharge.
They explain that the lightning signature in this region is characterized by a relatively slow, negative electric field event preceded by a pronounced opposite-polarity pulse. The average duration of the main waveform was about 500 microseconds and the average duration of the preceding opposite-polarity pulses was approximately 40 microseconds. These figures are based on measurements of more than 5000 lightning flashes.
A likely explanation may lie in the fact that Nepal has regions that are a mere 60 metres above sea level and then within just 160 kilometres we can figuratively scale the giddy heights of Mount Everest, the peak at 8848 metres above sea level. Moreover across this altitude gradient and through the course of the seasons, Nepal can have a temperature ranging from a balmy 30 degrees Celsius down to –50 Celsius. All such characteristics are unique of themselves and so it is perhaps no surprise that the lightning seen in this region is unique too.
It is worth pointing out that lightening signatures not dissimilar to the unique flashes measured in Nepal have been seen occasionally in Sweden and Florida but not at anything like the frequency compared to other flashes seen in Nepal.
Pitri Bhakta Adhikari, Unique lightning signatures observed from sub-tropical, mountainous country, Nepal, International Journal of Hydrology Science and Technology (2021). DOI: 10.1504/IJHST.2021.115488
The digestive system of cows influences human's vitamin B12 intake
What a cow eats determines how much vitamin B12 you get from milk!
Milk is the main source of vitamin B12 consumption for many people around the world. A glass of cow’s milk contains about 46% of the daily-recommended dietary intake of vitamin B12 for adults. But what factors influence the concentration of B12 in a glass of milk? Turns out, what cows eat and how they digest it can impact human’s B12 intake.
Many plants that grow on our planet cannot be used directly by humans as food. But cows have the ability to convert these plants into proteins and vitamins humans can consume through milk. Vitamin B12 comes from animal products, produced by microorganisms in the digestive tract of cows, sheep, and goats. Cow’s milk is an excellent natural source of B12, because of the abundance of bacteria in their digestive tract capable of producing the vitamin.
Specifically, cows have a digestive system that is uniquely different from our own. Instead of a single compartment to the stomach they have four. Of the four compartments, the rumen is the largest and the main digestive center filled with billions of microorganisms that are able to break down grass and other vegetation that animals with one stomach, including humans, cannot digest.
This research has found that certain microorganisms in the rumen of cows are linked to vitamin B12 abundance. Diets higher in acid detergent fibre, such as grass, tended to encourage increased vitamin B12 concentrations in milk. Alternativity, diets higher in starch and energy concentration, based feed tended to result in lower vitamin B12 concentrations. When the pH in the rumen is lower there tends to be higher production of vitamin B12. However, we do not know at this time if vitamin B12 concentration is driving changes in the microbiome or if the microbiome is driving changes in the concentration of vitamin B12.
Physicists dream big with an idea for a particle collider on the moon
A lunar particle accelerator could reach 1,000 times the energy of Earth’s largest collider
A very high energy hadron collider on the Moon
A particle collider encircling the moon could reach an energy of 14 quadrillion electron volts, physicists report June 6 at arXiv.org. That’s about 1,000 times the energy of the world’s biggest particle accelerator, the Large Hadron Collider, or LHC, at CERN near Geneva.
Such a fantastical machine would probably be buried under the moon’s surface to avoid wild temperature swings, the researchers say, and could be powered by a ring of solar panels around the moon.
The mere sight of illness may kick-start a canary’s immune system
Simply seeing another bird get sick is enough to trigger an immune response in healthy birds
For canaries, just seeing their feathered friends get sick may be enough to preemptively rev up their immune systems.
Healthy birds housed within view of fellow fowl infected with a common pathogenmounted an immune response, despite not being infected themselves, researchers report online June 9 inBiology Letters.
It’s fascinating that some sort of visual cue could alter immune function.
one experiment in humans found that a mere photo of a sick person increases the activity of inflammation-stimulating chemicals called cytokines. But no one had ever looked to see whether being within eyeshot of an actually sick individual could compel the immune system to preemptive action.
In the experiments researchers conducted, as healthy birds witnessed neighbors becoming visibly sick, their immune systems stirred. A measure of the birds’ ability to burst foreign cells, called CH50 complement activity, rose in conjunction with how sick the infected birds appeared. White blood cell counts were also significantly different in birds exposed to sick individuals, rather than healthy ones. Cytokine levels did not differ between the two groups.
Blood tests showed that no healthy birds caught MG during the experiment, suggesting that some sort of external cue altered immune function. That cue was likely visual.
Bodies May Treat Fast Food Like a Dangerous Infection
The immune system can respond to a fast food diet in much the same way it does to a bacterial infection, according to a 2018 study on mice, raising new questions about just how damaging regular trips to burger and pizza chains could be to our health.
Mice fed the equivalent of a "Western diet" high in saturated fats, sugar, and salt for a month, with nothing in the way of fresh fruit, vegetables, or fibre, were shown to increase the number of immune cells in their blood, just as they would if they'd been hit by a microbial infection.
What's more, this aggressive state of alarm that fast food triggers could stick around for the long term, said the international team of researchers – that's based onrecent researchinto the way our immune systems can remember aspects of past battles they've fought.
Those white blood cells pointed the scientists towards certain genes that were activated by the mouse diets, genes containingprogenitor cells– the types of cells responsible for raising up an immune cell army.
That genetic breadcrumb trail matters, because it's these progenitor cells that have previously been found to havea kind of memoryin dealing with biological attack.
In other words, once the body has started to react to a fast food diet, returning to a healthy eating regime may not be enough to completely undo the changes, and that's got some implications for our overall health.
Indeed, when the mice went back to their regular cereal diet after a month, the inflammation disappeared – but the genetic reprogramming that kept the mice more sensitive to a future attack stuck around.
New discovery shows human cells can write RNA sequences into DNA
Cells contain machinery that duplicates DNA into a new set that goes into a newly formed cell. That same class of machines, called polymerases, also build RNA messages, which are like notes copied from the central DNA repository of recipes, so they can be read more efficiently into proteins. But polymerases were thought to only work in one direction DNA into DNA or RNA. This prevents RNA messages from being rewritten back into the master recipe book of genomic DNA. Now, researchers provide the first evidence that RNA segments can be written back into DNA, which potentially challenges the central dogma in biology and could have wide implications affecting many fields of biology.
Polθ reverse transcribes RNA and promotes RNA-templated DNA repair, Science Advances (2021). DOI: 10.1126/sciadv.abf1771
South African worker honeybees reproduce by making near-perfect clones of themselves
A team of researchers has found that workers in a species of honeybee found in South Africa reproduce by making near-perfect clones of themselves.
Prior research has found that some creatures reproduce through parthenogenesis, in which individuals reproduce without mating. This form of reproduction has the advantage of not wasting time and energy on mating and the gene pool remains undiluted. The downside, of course, is loss of genetic diversity, which helps species survive in changing conditions. Prior research has also shown that for most species, parthenogenesis is a less-than-perfect way to produce offspring. This is because some tiny bit of genetic material is generally mixed wrong—these mistakes, known as recombinations, can lead to birth defects or non-productive eggs. In this new effort, the researchers have found a kind of honeybee that has developed a way to avoid recombinations.
The researchers found that South African Cape honeybee queens reproduce sexually, but the workers reproduce asexually.
They then conducted a small experiment—they affixed tape to the reproductive organs of a queen, preventing males from mating with her, and then allowed both her and the worker bees in the same hive to reproduce asexually. They then tested the degree of recombination in both. They found that offspring of the queen had approximately 100 times as much recombination as the worker bees. Even more impressive, the offspring of the worker bees were found to be nearly identical clones of their parent. More testing showed that one line of worker bees in the hive had been cloning themselves for approximately 30 years—a clear sign that workers in the hive were not suffering from birth defects or an inability to produce viable offspring. It also showed that they have evolved a means for preventing recombination when they reproduce. The researchers note that despite their unique abilities, the bees are still in line with evolutionary theory—they are simply doing what works best for their continued existence.
Benjamin P. Oldroyd et al, Adaptive, caste-specific changes to recombination rates in a thelytokous honeybee population, Proceedings of the Royal Society B: Biological Sciences (2021). DOI: 10.1098/rspb.2021.0729
A 36-year-old woman in South Africa with HIV carried Covid for 216 days, during which Covid viruses accumulated 32 mutations - 13 to the spike protein (could help Covid viruses escape immune responses).
If more such cases are found, it raises the prospect that HIV infection could be a source of new variants simply because the patients could carry the virus for longer.
Scientists only spotted this case because she was enrolled in a study of 300 people with HIV looking at their immune response to Covid.
The researchers also found that four other people with HIV had carried the coronavirus for longer than a month.
…there have been reported cases of people with kidney transplants testing positive for almost a year.
Dark matter is slowing the spin of the Milky Way's galactic bar
The spin of the Milky Way's galactic bar, which is made up of billions of clustered stars, has slowed by about a quarter since its formation, according to a new study by researchers.
For 30 years, astrophysicists have predicted such a slowdown, but this is the first time it has been measured.
The researchers say it gives a new type of insight into the nature of dark matter, which acts like a counterweight slowing the spin.
Researchers analysed Gaia space telescope observations of a large group of stars, the Hercules stream, which are in resonance with the bar—that is, they revolve around the galaxy at the same rate as the bar's spin.
These stars are gravitationally trapped by the spinning bar. The same phenomenon occurs with Jupiter's Trojan and Greek asteroids, which orbit Jupiter's Lagrange points (ahead and behind Jupiter). If the bar's spin slows down, these stars would be expected to move further out in the galaxy, keeping their orbital period matched to that of the bar's spin.
The researchers found that the stars in the stream carry a chemical fingerprint—they are richer in heavier elements (called metals in astronomy), proving that they have traveled away from the galactic center, where stars and star-forming gas are about 10 times as rich in metals compared to the outer galaxy.
Using this data, the team inferred that the bar—made up of billions of stars and trillions of solar masses—had slowed down its spin by at least 24% since it first formed.
The counterweight slowing this spin must be dark matter. Until now, researchers have only been able to infer dark matter by mapping the gravitational potential of galaxies and subtracting the contribution from visible matter.
This new research provides a new type of measurement of dark matter—not of its gravitational energy, but of its inertial mass (the dynamical response), which slows the bar's spin.
Rimpei Chiba et al, Tree-ring structure of Galactic bar resonance, Monthly Notices of the Royal Astronomical Society (2021). DOI: 10.1093/mnras/stab1094
Microbes in ocean play important role in moderating Earth's temperature
Methane is a strong greenhouse gas that plays a key role in Earth's climate. Anytime we use natural gas, whether we light up our kitchen stove or barbeque, we are using methane.
Only three sources on Earth produce methane naturally: volcanoes, subsurface water-rock interactions, and microbes. Between these three sources, most is generated by microbes, which have deposited hundreds of gigatons of methane into the deep seafloor. At seafloor methane seeps, it percolates upwards toward the open ocean, and microbial communities consume the majority of this methane before it reaches the atmosphere. Over the years, researchers are finding more and more methane beneath the seafloor, yet very little ever leaves the oceans and gets into the atmosphere. Where is the rest going?
A team of researchers now discovered that microbial communities that rapidly consume the methane, preventing its escape into Earth's atmosphere. The study published inProceedings of the National Academy of Sciencescollected and examined methane-eating microbes from seven geologically diverse seafloor seeps and found, most surprisingly, that the carbonate rocks from one site in particular hosts methane-oxidizing microbial communitieswith the highest rates of methane consumption measured to date.
The microbes in these carbonate rocks are acting like a methane bio filter consuming it all before it leaves the ocean.
Jeffrey J. Marlow el al., "Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2006857118
Scarce as they are, copper and iron metals are necessary for our survival, playing essential roles in human growth and metabolism. But one place we wouldn't expect to find either is clumped inside our brain cells.
However, for people with the neurodegenerative disorderAlzheimer'sdisease, something seems to be turning these elements into microscopic ingots.
A team of researchers from the US and UK spotted the tell-tale glint of copper and iron in their elemental forms using a form of X-ray microscopy (STXM) on samples of neural plaques taken from the frontal and temporal lobes of Alzheimer's patients.
Plaques are a typical feature of this particular form of dementia, made up of proteins broken down into what's known as beta-amyloid.
Yet therapies focused on clearing clumps of beta-amyloid from the brain haven't led us much closer to a treatment for Alzheimer's, leaving researcherswondering what role– if any – they play in the disease's progress.
One angle that hasn't been fully explored is the toxic effect of biomineralization, or the accumulation ofminerals such as hematitein brain cells.
Trapped as a charged ionic form inside hemoglobin, iron is a handy way to transport oxygen around the body. And few places are as desperate for oxygen as the human brain.
Once released from its protein shackles, however, iron shows its nasty side as what's known as itslabile form, generating reactive species of oxygen that wreak havoc on delicate biochemistry and destroying cells.
High levels of labile iron have beenlinked to neurodegenerative disorderslike Alzheimer's before. Similarly, copper is another mineral typically shielded safely in a protein, yetthoroughly capableof making a mess of our brains in labile form.
New treatment stops progression of Alzheimer's disease in monkey brains
A new therapy prompts immune defense cells to swallow misshapen proteins, amyloid beta plaques and tau tangles, whose buildup is known to kill nearby brain cells as part of Alzheimer's disease, a new study shows.
Led by researchers at NYU Grossman School of Medicine, the investigation showed that elderly monkeys had up to 59 percent fewer plaque deposits in their brains after treatment with CpG oligodeoxynucleotides (CpG ODN), compared with untreated animals. Theseamyloid beta plaquesare protein fragments that clump together and clog the junctions betweennerve cells(neurons).
Brains of treated animals also had a drop in levels of toxic tau. This nerve fiber protein can destroy neighboring tissue when disease-related changes to its chemical structure causes it to catch on other cells.
Study finds association between head impacts and imaging changes in youth football players
A new study shows that head impacts experienced during practice are associated with changes in brain imaging of young players over multiple seasons.
A group of 16 youth athletes who participated in non-contact sports, such as swimming, tennis and track, served as the control group in the study.
Pre- and post-season MRIs were completed for both groups of study participants using diffusion tensor imaging (DTI), a type of neuroimaging that can be used to assess the integrity of the brain's white matter, indicating possible sites of injury.
In addition, the research team gathered biomechanical data of linear and rotational head accelerations of head impacts from the football group during all practice and games via the Riddell Head Impact Telemetry System in the helmets. That information was transmitted in real time to a sideline data collection field unit for later analysis.
In 19 of the 47 youth football athletes, brain images were obtained pre- and post-season for two consecutive football seasons. Using data from the DTIs and the head impact telemetry system, the researchers found variations in head impact exposures (i.e., the number and severity of head impacts measured) from year-to-year and between athletes. For example, in an examination of data from three consecutive seasons, some youths experienced more impacts in their second year of play than in their first, while other youths experienced fewer impacts in later years of play.
They observed variability in the amount and direction of imaging changes in the brain related to the amount of exposure that the players experienced on the field. If efforts are taken to reduce that exposure on-field, changes in brain imaging can be potentially mitigated.
These findings further support ongoing efforts to reduce the number of head impacts in football practices.
Combining classical and quantum computing opens door to new discoveries
Researchers have discovered a new and more efficient computing method for pairing the reliability of a classical computer with the strength of a quantum system.
This new computing method opens the door to different algorithms and experiments that bring quantum researchers closer to near-term applications and discoveries of the technology.
In the future, quantum computers could be used in a wide variety of applications including helping to remove carbon dioxide from the atmosphere, developing artificial limbs and designing more efficient pharmaceuticals.
The research team is the first to propose the measurement-based approach in afeedback loopwith a regularcomputer, inventing a new way to tackle hard computing problems. Their method is resource-efficient and therefore can use small quantum states because they are custom-tailored to specific types of problems.
Hybrid computing, where a regular computer's processor and a quantum co-processor are paired into a feedback loop, gives researchers a more robust and flexible approach than trying to use a quantum computer alone.
While researchers are currently building hybrid, computers based on quantum gates, this research team was interested in the quantum computations that could be done without gates. They designed an algorithm in which a hybrid quantum-classical computation is carried out by performing a sequence of measurements on an entangled quantum state.
The team's theoretical research is good news for quantum software developers and experimentalists because it provides a new way of thinking about optimization algorithms. The algorithm offers high error tolerance, often an issue in quantum systems, and works for a wide range of quantum systems, including photonic quantum co-processors.
R. R. Ferguson et al, Measurement-Based Variational Quantum Eigensolver, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.220501
A previously unreported anatomical structure named the 'cantil' has been described in the popular plant model, Arabidopsis thaliana. Scientists reveal that the cantil forms between the stem and flower-bearing stalk when flowering is delayed. Published in the journal Development, this study highlights that there are still discoveries to be made, even in some of the most meticulously studied species, and provides new clues for understanding conditional growth in plants.
Cantils are rare; they only develop under certain conditions that cause the plant to delay flowering, such as short day lengths, and cantils only form at the precise point at which the plant begins to flower.
However, some popular Arabidopsis strains have genetic mutations that make them incapable of producing cantils at all.
Gookin, T. E. and Assmann, S. M. (2021). Cantil: a previously unreported organ in wild-type Arabidopsis regulated by FT, ERECTA and heterotrimeric G proteins. Development, 148, dev195545. DOI: 10.1242/dev.195545
Photoemission is a property of metals and other materials that emit electrons when struck by light. Electron emission after light absorption was already explained by Albert Einstein. But since this effect is a highly complex process, scientists have still not been able to fully elucidate its details. Prof. Dr. Bernd von Issendorff and his team at the University of Freiburg's Institute of Physics have now succeeded in detecting a previously unknown quantum effect in the angular distributions of photoelectrons from cryogenic mass-selected metal clusters. The angular distributions resemble those of classical particles, a behavior that is surprisingly explainable by the strong electron-electron interaction in these many-electron systems. The researchers published this finding in the current issue of Physical Review Letters.
Many cosmetics sold in the United States and Canada likely contain high levels of per- and polyfluoroalkyl substances (PFAS), a potentially toxic class of chemicals linked to a number of serious health conditions, according to new research from the University of Notre Dame.
More than half the cosmetics sold in the United States and Canada likely contain high levels of a toxic industrial compound linked to serious health conditions, including cancer and reduced birth weight, according to a new study.
Use of PFAS in cosmetics 'widespread,' new study finds
Many cosmetics sold in the United States and Canada likely contain high levels of per- and polyfluoroalkyl substances (PFAS), a potentially toxic class of chemicals linked to a number of serious health conditions, according to new research from the University of Notre Dame.
Scientists tested more than 200 cosmetics including concealers, foundations, eye and eyebrow products and various lip products. According to the study, 56 percent of foundations and eye products, 48 percent of lip products and 47 percent of mascaras tested were found to contain high levels of fluorine, which is an indicator of PFAS use in the product. The study was recently published in the journal of Environmental Science and Technology Letters.
There's the individual risk—these are products that are applied around the eyes and mouth with the potential for absorption through the skin or at the tear duct, as well as possible inhalation or ingestion. PFAS is a persistent chemcial—when it gets into the bloodstream, it stays there and accumulates. There's also the additional risk of environmental contamination associated with the manufacture and disposal of these products, which could affect many more people.
Studies have linked certain PFAS to kidney cancer, testicular cancer, hypertension, thyroid disease, low birth weight and immunotoxicity in children.
Heather D. Whitehead et al, Fluorinated Compounds in North American Cosmetics, Environmental Science & Technology Letters (2021). DOI: 10.1021/acs.estlett.1c00240
New material could remove respiratory droplets from air
Although plexiglass barriers are seemingly everywhere these days—between grocery store lanes, around restaurant tables and towering above office cubicles—they are an imperfect solution to blocking virus transmission.
Instead of capturing virus-ladenrespiratory dropletsand aerosols, plexiglass dividers merely deflectdroplets, causing them to bounce away but remain in the air. To enhance the function of these protective barriers, Northwestern University researchers have developed a new transparent material that can capture droplets and aerosols, effectively removing them from air.
The material is a clear, viscous liquid that can be painted onto any surface, including plastic, glass, wood, metal, stainless steel, concrete and textiles. When droplets collide with the coated surface, they stick to it, get absorbed and dry up. The coating also is compatible with antiviral and antimicrobial materials, so sanitizing agents, such as copper, could be added to the formula.
Genetically engineered nanoparticle delivers dexamethasone directly to inflamed lungs
Nanoengineers at the University of California San Diego have developed immune cell-mimicking nanoparticles that target inflammation in the lungs and deliver drugs directly where they're needed. As a proof of concept, the researchers filled the nanoparticles with the drug dexamethasone and administered them to mice with inflamed lung tissue. Inflammation was completely treated in mice given the nanoparticles, at a drug concentration where standard delivery methods did not have any efficacy.
What's special about these nanoparticles is that they are coated in a cell membrane that's been genetically engineered to look for and bind to inflamed lung cells. They are the latest in the line of so-called cell membrane-coated nanoparticles.
But while these previous cell membranes were naturally derived from the body'scells, the cell membranes used to coat this dexamethasone-filled nanoparticle were not.
"In this paper, researchers used a genetic engineering approach to edit thesurface proteinson the cells before we collected the membranes. This significantly advanced our technology by allowing us to precisely overexpress certain functional proteins on the membranes or knockout some undesirable proteins.
Giant Rats Are Sniffing Out Landmines and Tuberculosis
These 2-foot giant pouched rats are giving rats a good name. Referred to as 'Hero Rats', they have a superpower that's saving thousands of lives: a powerful nose that can detect unexploded landmines and Tuberculosis. And now, they're being trained to sniff out just about anything, from illegal wildlife trafficking to humans trapped under rubble after a natural disaster.
Physicists bring human-scale object to near standstill, reaching a quantum state
To the human eye, most stationary objects appear to be just that—still, and completely at rest. Yet if we were handed a quantum lens, allowing us to see objects at the scale of individual atoms, what was an apple sitting idly on our desk would appear as a teeming collection of vibrating particles, very much in motion.
In the last few decades, physicists have found ways to super-cool objects so that their atoms are at a near standstill, or in their "motionalground state." To date, physicists have wrestled small objects such as clouds of millions of atoms, or nanogram-scale objects, into such pure quantum states.
Now for the first time, scientists at MIT and elsewhere have cooled a large, human-scaleobjectto close to its motional ground state. The object isn't tangible in the sense of being situated at one location, but is the combined motion of four separate objects, each weighing about 40 kilograms. The "object" that the researchers cooled has an estimated mass of about 10 kilograms, and comprises about 1x1026, or nearly 1 octillion, atoms.
The researchers took advantage of the ability of the Laser Interfrometer Gravitational-wave Observatory (LIGO) to measure the motion of the masses with extreme precision and super-cool the collective motion of the masses to 77 nanokelvins, just shy of the object's predicted ground state of 10 nanokelvins.
Their results, appearing today inScience, represent the largest object to be cooled to close to its motional ground state. The scientists say they now have a chance to observe the effect of gravity on a massive quantum object.
Giant spider webs blanket Australian landscape after heavy rainfall
Stunning photographs of vast, ghostly spider webs blanketing the flood-affected region of Gippsland in Victoria have gone viral online, prompting many to muse on the wonder of nature.
But what's going on here? Why do spiders do this after floods and does it happen everywhere?
The answer is: these webs have nothing to do with spiders trying to catch food. Spiders often use silk to move around and in this case are using long strands of web to escape from waterlogged soil.
When these flood events happen, they need evacuate quickly up out of holes they live in underground. They come out en masse and use their silk to help them do that.
You'll often see juvenile spiders let out a long strand of silk which is caught by the wind and lifted up. The web catches onto another object such as a tree and allows the spider to climb up.
That's how baby spiders (spiderlings!) disperse when they emerge from their egg sacs – it's called ballooning. They have to disperse as quickly as possible because they are highly cannibalistic so they need to move away from each other swiftly and find their own sites to hunt or build their webs.
Bacteria can recover precious metals from electric vehicle batteries
Bioleaching, also called biomining, employs microbes which can oxidise metal as part of their metabolism. It has been widely used in the mining industry, where microorganisms are used to extract valuable metals from ores. More recently, this technique has been used to clean up and recover materials from electronic waste, particularly the printed circuit boards of computers, solar panels, contaminated water and even uranium dumps.
All metals present in EV batteries can be recovered using bioleaching. Bacteria like Acidithiobacillus ferrooxidans and other non-toxic species target and recover the metals individually without the need for high temperatures or toxic chemicals. These purified metals constitute chemical elements, and so can be recycled indefinitely into multiple supply chains.
Scaling up bioleaching involves growing bacteria in incubators at 37°C, often using carbon dioxide. Not a lot of energy is needed, so the process has a much smaller carbon footprint than typical recycling plants, while also contributing less pollution. While reducing EV battery waste, bioleaching facilities mean manufacturers can recover these precious metals locally, and rely less on the few producer countries.
EV batteries are a technology still in their infancy. The reuse of their components should be considered as part of their design. Rather than remaining an afterthought, recycling can become both the beginning and end of an EV battery’s life cycle with bioleaching, producing high-quality raw materials for new batteries at low environmental cost.
Dr. Krishna Kumari Challa
Part 4:
Footnotes:
Jun 7, 2021
Dr. Krishna Kumari Challa
A framework to simulate the same physics using two different Hamiltonians
Researchers have recently been investigating situations in which two distinct Hamiltonians could be used to simulate the same physical phenomena. A Hamiltonian is a function or model used to describe a dynamic system, such as the motion of particles.
In a paper published in Physical Review Letters, researchers introduced a framework that could prove useful for simulating the same physics with two distinct Hamiltonians. In addition, they provide an example of an analog simulation and show how one could build an alternative version of a digital quantum simulator.
Their result indicates that using the same Hamiltonian is not always a necessary condition. As an example, they showed that the physics of one-axis twisting can be simulated by a spin chain with an external field, even though the one-axis twisting model has infinite range interactions and this spin chain model has only nearest-neighboring interactions. The Hamiltonian of these two models are physically different, i.e. having different energy spectra, but still one can simulate the one with the other if the dynamics starts with special states.
Simulating the same physics with two distinct Hamiltonians. Physical Review Letters(2021). DOI: 10.1103/PhysRevLett.126.160402.
https://phys.org/news/2021-06-framework-simulate-physics-hamiltonia...
Jun 8, 2021
Dr. Krishna Kumari Challa
A new material made from carbon nanotubes can generate electricity by scavenging energy from its environment
Engineers have discovered a new way of generating electricity using tiny carbon particles that can create a current simply by interacting with liquid surrounding them.
The liquid, an organic solvent, draws electrons out of the particles, generating a current that could be used to drive chemical reactions or to power micro- or nanoscale robots, the researchers say.
"This mechanism is new, and this way of generating energy is completely new.
When a carbon nanotube is coated with layer of fuel, moving pulses of heat, or thermopower waves, travel along the tube, creating an electrical current.
This technology is intriguing because all you have to do is flow a solvent through a bed of these particles. This allows you to do electrochemistry, but with no wires.
In a new study describing this phenomenon, the researchers showed that they could use this electric current to drive a reaction known as alcohol oxidation—an organic chemical reaction that is important in the chemical industry.
Albert Tianxiang Liu et al, Solvent-induced electrochemistry at an electrically asymmetric carbon Janus particle, Nature Communications (2021). DOI: 10.1038/s41467-021-23038-7
https://phys.org/news/2021-06-material-carbon-nanotubes-electricity...
Jun 8, 2021
Dr. Krishna Kumari Challa
Physicists report definitive evidence how auroras are created
The aurora borealis, or northern lights, that fill the sky in high-latitude regions have fascinated people for thousands of years. But how they're created, while theorized, had not been conclusively proven till recently.
In a new study, a team of physicists reports definitive evidence that the most brilliant auroras are produced by powerful electromagnetic waves during geomagnetic storms. The phenomena, known as Alfven waves, accelerate electrons toward Earth, causing the particles to produce the familiar atmospheric light show.
The study, published online June 7 in the journal Nature Communications, concludes a decades-long quest to demonstrate experimentally the physical mechanisms for the acceleration of electrons by Alfven waves under conditions corresponding to Earth's auroral magnetosphere.
Measurements revealed this small population of electrons undergoes 'resonant acceleration' by the Alfven wave's electric field, similar to a surfer catching a wave and being continually accelerated as the surfer moves along with the wave.
Laboratory measurements of the physics of auroral electron acceleration by Alfvén waves, Nature Communications (2021). DOI: 10.1038/s41467-021-23377-5 , www.nature.com/articles/s41467-021-23377-5
Jun 8, 2021
Dr. Krishna Kumari Challa
part 2:
Scientists have known that energized particles that emanate from the sun—such as electrons racing at approximately 45 million miles per hour—precipitate along the Earth's magnetic field lines into the upper atmosphere, where they collide with oxygen and nitrogen molecules, kicking them into an excited state. These excited molecules relax by emitting light, producing the colorful hues of the aurora.
The theory was supported by spacecraft missions that frequently found Alfven waves traveling Earthward above auroras, presumably accelerating electrons along the way. Although space-based measurements had supported the theory, limitations inherent to spacecraft and rocket measurements had prevented a definitive test.
The physicists were able to find confirmatory evidence in a series of experiments conducted at the Large Plasma Device (LPD) in UCLA's Basic Plasma Science Facility, a national collaborative research facility supported jointly by the U.S. Department of Energy and National Science Foundation.
https://phys.org/news/2021-06-physicists-definitive-evidence-aurora...
Jun 8, 2021
Dr. Krishna Kumari Challa
Turning off lights can save migrating birds from crashing into buildings
Every night during the spring and fall migration seasons, thousands of birds are killed when they crash into illuminated windows, disoriented by the light. But a new study in PNAS shows that darkening just half of a building's windows can make a big difference for birds. Using decades' worth of data and birds collected by Field Museum scientists at Chicago's McCormick Place convention center, the researchers found that on nights when half the windows were darkened, there were 11 times fewer bird collisions during spring migration and 6 times fewer collisions during fall migration than when all the windows were lit.
This research provides the best evidence yet that migrating birds are attracted to building lights, often causing them to collide with windows and die. And that turning off the lights can save the birds.
Benjamin M. Van Doren el al., "Drivers of fatal bird collisions in an urban center," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2101666118
https://phys.org/news/2021-06-migrating-birds.html?utm_source=nwlet...
Jun 8, 2021
Dr. Krishna Kumari Challa
Bacteriophages prove to be more effective at fighting antibiotic resistance when trained
The threat of antibiotic resistance rises as bacteria continue to evolve to foil even the most powerful modern drug treatments. By 2050, antibiotic resistant-bacteria threaten to claim more than 10 million lives as existing therapies prove ineffective.
Bacteriophage, or "phage," have become a new source of hope against growing antibiotic resistance. Ignored for decades by western science, phages have become the subject of increasing research attention due to their capability to infect and kill bacterial threats.
A new project has provided evidence that phages that undergo special evolutionary training increase their capacity to subdue bacteria. Like a boxer in training ahead of a title bout, pre-trained phages demonstrated they could delay the onset of bacterial resistance.
The trained phage had already experienced ways that the bacteria would try to dodge it. It had 'learned' in a genetic sense. It had already evolved mutations to help it counteract those moves that the bacteria were taking. Scientists are using phage's own improvement algorithm, evolution by natural selection, to regain its therapeutic potential and solve the problem of bacteria evolving resistance to yet another therapy.
The researchers are now extending their findings to research how pre-trained phages perform on bacteria important in clinical settings, such as E. coli. They are also working to evaluate how well training methods work in animal models.
Joshua M. Borin et al, Coevolutionary phage training leads to greater bacterial suppression and delays the evolution of phage resistance, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2104592118
https://phys.org/news/2021-06-viruses-effective-antibiotic-resistan...
Jun 8, 2021
Dr. Krishna Kumari Challa
World's first blood test for real-time monitoring of cancer treatme...
Cancer patients who are undergoing targeted therapy can look forward to a new blood test that could tell their doctors whether the treatment is working, within one day after the start of the treatment. This will significantly speed up the evaluation process and enable doctors to make adjustments to the treatment plan, if necessary, to improve patients' chances of recovery.
Sijun Pan et al, Extracellular vesicle drug occupancy enables real-time monitoring of targeted cancer therapy, Nature Nanotechnology (2021). DOI: 10.1038/s41565-021-00872-w
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How coronavirus aerosols travel through lungs
More than 65% of inhaled coronavirus particles reach the deepest region of our lungs where damage to cells can lead to low blood oxygen levels, new research has discovered, and more of these aerosols reach the right lung than the left.
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Infrared imaging leaves invasive pythons nowhere to hide
For more than 25 years, Burmese pythons have been living and breeding in the Florida Everglades, where they prey on native wildlife and disrupt the region's delicate ecosystems. A new study shows that infrared cameras could make it easier to spot these invasive snakes in the Florida foliage, providing a new tool in the effort to remove them.
Jun 8, 2021
Dr. Krishna Kumari Challa
Studies reveal skull as unexpected source of brain immunity
he immune system is the brain’s best frenemy. It protects the brain from infection and helps injured tissues heal, but it also causes autoimmune diseases and creates inflammation that drives neurodegeneration.
Two new studies in mice suggest that the double-edged nature of the relationship between the immune system and the brain may come down to the origins of the immune cells that patrol the meninges, the tissues that surround the brain and spinal cord. In complementary studies published June 3 in the journal Science, two teams of researchers unexpectedly found that many of the immune cells in the meninges come from bone marrow in the skull and migrate to the brain through special channels without passing through the blood.
These skull-derived immune cells are peacekeepers, dedicated to maintaining a healthy status quo. It’s the other immune cells, the ones that arrive from the bloodstream, that seem to be the troublemakers. They carry genetic signatures that mark them as likely to promote autoimmunity and inflammation, and they become more abundant with aging or under conditions of disease or injury. Taken together, the findings reveal a key aspect of the connection between the brain and the immune system that could inform our understanding of a wide range of brain disorders.
https://researchnews.cc/news/7122/Studies-reveal-skull-as-unexpecte...
https://www.sciencedaily.com/releases/2021/06/210603171058.htm
Jun 8, 2021
Dr. Krishna Kumari Challa
Defying body clock linked to depression and lower wellbeing
People whose sleep pattern goes against their natural body clock are more likely to have depression and lower levels of wellbeing, according to a largescale new study.
This research also found the most robust evidence to date that being genetically programmed to be an early riser is protective against major depression, and improves wellbeing. Researchers suggest this may be because society is set up to be more aligned to early risers, through the standard 9-5 working pattern.
Molecular Psychiatry (2021). www.nature.com/articles/s41380-021-01157-3
https://medicalxpress.com/news/2021-06-defying-body-clock-linked-de...
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Climate change is making ocean waves more powerful, threatening to ...
Sea level rise isn't the only way climate change will devastate the coast. Our research, published today, found it is also making waves more powerful, particularly in the Southern Hemisphere.
Jun 9, 2021
Dr. Krishna Kumari Challa
Scientists can predict which women will have serious pregnancy complications
Women who will develop potentially life-threatening disorders during pregnancy can be identified early when hormone levels in the placenta are tested, a new study has shown.
Pregnancy disorders affect around one in ten pregnant women. Nearly all of the organ systems of the mother's body need to alter their function during pregnancy so that the baby can grow. If the mother's body cannot properly adapt to the growing baby this leads to major and common issues including fetal growth restriction, fetal over-growth, gestational diabetes, and preeclampsia—a life-threatening high blood pressure in the mother.
Many of these complications lead to difficult labors for women with more medical intervention and lifelong issues for the baby including diabetes, heart issues and obesity.
Pregnancy disorders are usually diagnosed during the second or third trimester of gestation when they have often already had a serious impact on the health of the mother and baby. The current methods to diagnose pregnancy disorders are not sensitive or reliable enough to identify all at risk pregnancies.
Now scientists have found a way to test hormone levels in the placenta to predict which women will have serious pregnancy complications.
This study found hormonal biomarkers from the placenta could indicate which women would have pregnancy complications. We found that these biomarkers are present from the first trimester of pregnancy, normally women are only diagnosed with complications during the second or third trimester when disorders may already have had serious consequences for the health of the mother and her developing baby.
Nature Communications Biology (2021). DOI: 10.1038/s42003-021-02214-x
https://medicalxpress.com/news/2021-06-scientists-women-pregnancy-c...
Jun 9, 2021
Dr. Krishna Kumari Challa
Subatomic particle seen changing to antiparticle and back
Physicists have proved that a subatomic particle can switch into its antiparticle alter-ego and back again, in a new discovery revealed recently.
The extraordinarily precise measurement was made by UK researchers using the Large Hadron Collider beauty (LHCb) experiment at CERN.
It has provided the first evidence that charm mesons can change into their antiparticle and back again.
For more than 10 years, scientists have known that charm mesons, subatomic particles that contain a quark and an antiquark, can travel as a mixture of their particle and antiparticle states.
It is a phenomenon called mixing.
However, this new result shows for the first time that they can oscillate between the two states.
Armed with this new evidence, scientists can try to tackle some of the biggest questions in physics around how particles behave outside of the Standard Model.
One being, whether these transitions are caused by unknown particles not predicted by the guiding theory.
The research, submitted to Physical Review Letters and available on arXiv.
Observation of the mass difference between neutral charm-meson eigenstates. arXiv:2106.03744v1 [hep-ex] arxiv.org/abs/2106.03744
https://phys.org/news/2021-06-subatomic-particle-antiparticle.html?...
Jun 9, 2021
Dr. Krishna Kumari Challa
Why Arctic soil can go slip-sliding away
Slow-moving arctic soils form patterns that, from a distance, resemble those found in common fluids such as drips in paint and birthday cake icing. Los Alamos researchers and their collaborators analyzed existing arctic soil formations and compared them to viscous fluids, determining that there is a physical explanation for this pattern that is common to both Earth and Mars landscapes.
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Algae blooms harmful to aquaculture: UN global assessment
Potentially lethal marine algae blooms have not increased in number over the last three decades, but pose a serious threat to aquaculture, according to a UN global assessment released recently.
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Bacteria-sized robots take on microplastics and win by breaking the...
Small pieces of plastic are everywhere, stretching from urban environments to pristine wilderness. Left to their own devices, it can take hundreds of years for them to degrade completely. Catalysts activated by sunlight could speed up the process, but getting these compounds to interact with microplastics is difficult. In a proof-of-concept study, researchers reporting in ACS Applied Materials & Interfaces developed self-propelled microrobots that can swim, attach to plastics and break them down.
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Normal breathing sends saliva droplets 7 feet; masks shorten this
The World Health Organization and the Centers for Disease Control recommend keeping a certain distance between people to prevent the spread of COVID-19. These social distancing recommendations are estimated from a variety of studies, but further research about the precise mechanism of virus transport from one person to another is still needed.
Jun 9, 2021
Dr. Krishna Kumari Challa
Cloud Avalanche
This "cloud avalanche" occurred near the Kapuche Glacier Lake in the mountains of Nepal last month. At that time, a group of travel companions were camping by the lake, and they took the risk of taking pictures of this rare visual feast. The white snow clouds rushed down the valley, unstoppable, instantly swallowing the mountains and hitting the lake surface. Against the backdrop of the blue sky and the yellow-brown mountains, they were more distinct, magnificent and shocking. The strong air flow overturned the tents and sleeping bags, frightening the travellers, but fortunately no casualties were reported. After that, a small rainbow appeared by the lake, which was extremely beautiful, and the travelers all cheered and marveled at it. Call it "perfect cloud collapse".
Jun 9, 2021
Dr. Krishna Kumari Challa
Popularity runs in families
Jun 10, 2021
Dr. Krishna Kumari Challa
Low Doses of "Laughing Gas" Could Be Fast, Effective Treatment for Severe Depression
Jun 10, 2021
Dr. Krishna Kumari Challa
Bacteria-sized robots take on microplastics and win by breaking them down
Small pieces of plastic are everywhere, stretching from urban environments to pristine wilderness. Left to their own devices, it can take hundreds of years for them to degrade completely. Catalysts activated by sunlight could speed up the process, but getting these compounds to interact with microplastics is difficult. In a proof-of-concept study, researchers reporting in ACS Applied Materials & Interfaces developed self-propelled microrobots that can swim, attach to plastics and break them down.
While plastic products are omnipresent indoors, plastic waste and broken bits now litter the outdoors, too. The smallest of these—microplastics less than 5 mm in size—are hard to pick up and remove. In addition, they can adsorb heavy metals and pollutants, potentially harming humans or animals if accidently consumed. So, previous researchers proposed a low-energy way to get rid of plastics in the environment by using catalysts that use sunlight to produce highly reactive compounds that break down these types of polymers. However, getting the catalysts and tiny plastic pieces in contact with each other is challenging and usually requires pretreatments or bulky mechanical stirrers, which aren't easily scaled-up. so wanted to create a sunlight-propelled catalyst that moves toward and latches onto microparticles and dismantles them.
To transform a catalytic material into light-driven microrobots, the researchers made star-shaped particles of bismuth vanadate and then evenly coated the 4–8 µm-wide structures with magnetic iron oxide. The microrobots could swim down a maze of channels and interact with microplastic pieces along their entire lengths. The researchers found that under visible light, microrobots strongly glommed on to four common types of plastics. The team then illuminated pieces of the four plastics covered with the microrobot catalyst for seven days in a dilute hydrogen peroxide solution. They observed that the plastic lost 3% of its weight and that the surface texture for all types changed from smooth to pitted, and small molecules and components of the plastics were found in the left-over solution. The researchers say the self-propelled microrobot catalysts pave the way toward systems that can capture and degrade microplastics in hard-to-reach-locations.
Seyyed Mohsen Beladi-Mousavi et al, A Maze in Plastic Wastes: Autonomous Motile Photocatalytic Microrobots against Microplastics, ACS Applied Materials & Interfaces (2021). DOI: 10.1021/acsami.1c04559
https://phys.org/news/2021-06-bacteria-sized-robots-microplastics.h...
Jun 10, 2021
Dr. Krishna Kumari Challa
Researchers create quantum microscope that can see the impossible
In a major scientific leap, researchers have created a quantum microscope that can reveal biological structures that would otherwise be impossible to see.
This paves the way for applications in biotechnology, and could extend far beyond this into areas ranging from navigation to medical imaging.
The microscope is powered by the science of quantum entanglement, an effect Einstein described as "spooky interactions at a distance".
The quantum entanglement in this microscope provides 35 percent improved clarity without destroying the cell, allowing us to see minute biological structures that would otherwise be invisible.
"The benefits are obvious—from a better understanding of living systems, to improved diagnostic technologies.
Quantum-enhanced nonlinear microscopy, Nature (2021). DOI: 10.1038/s41586-021-03528-w , www.nature.com/articles/s41586-021-03528-w
https://phys.org/news/2021-06-quantum-microscope-impossible.html?ut...
Jun 10, 2021
Dr. Krishna Kumari Challa
Scientists Have Calculated The Weight of All The SARS-CoV-2 in The World
A group of researchers recently calculated that each infected individual carries about 10 billion to 100 billion individual SARS-CoV-2 particles at the peak of their infection. That suggests that all of the SARS-CoV-2 viruses currently infecting people around the world — which has been about 1 million to 10 million infections at any given time during the course of the pandemic — have a collective mass of somewhere between 0.22 and 22 pounds (0.1 and 10 kilograms).
Small doesn't mean insignificant, however.
Here we are talking about a super-tiny mass of viruses, and they are completely wreaking havoc on the world.
The total number and mass of SARS-CoV-2 virions
https://www.pnas.org/content/118/25/e2024815118/tab-article-info
https://www.sciencealert.com/how-much-does-all-the-sars-cov-2-in-th...
Jun 10, 2021
Dr. Krishna Kumari Challa
AMAZING Cases of Animal MIMICRY!
Jun 11, 2021
Dr. Krishna Kumari Challa
'Vegan spider silk' provides sustainable alternative to single-use plastics
Researchers have created a plant-based, sustainable, scalable material that could replace single-use plastics in many consumer products.
The researchers, from the University of Cambridge, created a polymer film by mimicking the properties of spider silk, one of the strongest materials in nature. The new material is as strong as many common plastics in use today and could replace plastic in many common household products.
The material was created using a new approach for assembling plant proteins into materials which mimic silk on a molecular level. The energy-efficient method, which uses sustainable ingredients, results in a plastic-like free-standing film, which can be made at industrial scale. Non-fading 'structural' color can be added to the polymer, and it can also be used to make water-resistant coatings.
The material is home compostable, whereas other types of bioplastics require industrial composting facilities to degrade.
Nature Communications (2021). DOI: 10.1038/s41467-021-23813-6
https://phys.org/news/2021-06-vegan-spider-silk-sustainable-alterna...
Jun 11, 2021
Dr. Krishna Kumari Challa
How cells measure themselves
Ever since scientists discovered cells under the microscope more than 350 years ago, they have noted that each type of cell has a characteristic size. From tiny bacteria to inches-long neurons, size matters for how cells work. The question of how these building blocks of life regulate their own size, however, has remained a mystery.
Now we have an explanation for this long-standing biological question. In a study focusing on the growing tip of plants, researchers show that cells use their DNA content as an internal gauge to assess and adjust their size.
"Cell size controlled in plants using DNA content as an internal scale" Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abb4348
https://phys.org/news/2021-06-cells.html?utm_source=nwletter&ut...
How cells measure themselves
Jun 11, 2021
Dr. Krishna Kumari Challa
Hydrogen sulfide critical to innate ability of bacteria to survive antibiotics
The signaling molecule hydrogen sulfide (H2S) plays a critical role in antibiotic tolerance, the innate ability of bacteria to survive normally lethal levels of antibiotics, a new study finds.
the study revolves around tolerance, wherein bacteria in general have evolved to use common defense systems to resist antibiotics. Tolerance differs from antibiotic resistance, where one species happens to acquire a genetic change that helps them resist treatment.
In one defense mechanism, tolerant bacteria, also called "persisters," stop multiplying (proliferating), reducing their energy use (metabolism) to survive antibiotic treatment, but resuming growth when the treatment ends. Persisters are particularly abundant in biofilms, bacterial colonies that live in tough polymeric matrices which further prevent their eradication.
The combined trends toward resistant infections and fewer new antimicrobials are projected to kill 10 million people annually by the year 2050. New approaches are urgently needed to prevent this, and this study suggests that suppressing bacterial H2S would make different antibiotics more potent.
K. Shatalin el al., "Inhibitors of bacterial H2S biogenesis targeting antibiotic resistance and tolerance," Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abd8377
https://phys.org/news/2021-06-hydrogen-sulfide-critical-innate-abil...
Jun 11, 2021
Dr. Krishna Kumari Challa
Researchers have turned transparent calcite into artificial gold
In a breakthrough in metamaterials, for the first time in the world, researchers at Tel Aviv University have developed an innovative nanotechnology that transforms a transparent calcite nanoparticle into a sparkling gold-like particle. In other words, they turned the transparent particle into a particle that is visible despite its very small dimensions. According to the researchers the new material can serve as a platform for innovative cancer treatments.
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Injectable microspheres to repair failing hearts
Biodegradable microspheres can be used to deliver heart cells generated from stem cells to repair damaged hearts after a heart attack, according to new findings by UCL researchers. This type of cell therapy could one day cure debilitating heart failure, which affects an estimated 920,000 people in the UK and continues to rise as more people are surviving a heart attack than ever before.
Jun 11, 2021
Dr. Krishna Kumari Challa
Nepal's unique lightning signature involves up to four strikes per flash
While every lightning flash is unique in the way the discharge travels through the atmosphere, whether cloud-to-cloud, cloud-to-ground or the more esoteric sprites, halos, jets, and elves of the upper atmosphere. There are common features in these different types of lightning and for cloud-to-ground flashes, it has been assumed that there are two main types of flash known to meteorologists and atmospheric scientists—negative ground flashes and positive ground flashes.
The difference between the negative and positive flash is simply that the polarity of the discharge reaching the ground in the lightning flash. Most (90 percent) cloud-to-ground flashes are negative ground flashes. Just 10 percent are positive. The positive ground flash involves a single stroke.
A novel phenomenon has been found in the sub-tropical, mountainous region of Nepal now.
Researchers have used a simple circuit and antenna system to measure the electrical signature of lightning flashes in the Himalayan region and found that positive ground flashes there are unique. Instead of involving a single strike, lightning here involves up to four strikes per flash, or discharge.
They explain that the lightning signature in this region is characterized by a relatively slow, negative electric field event preceded by a pronounced opposite-polarity pulse. The average duration of the main waveform was about 500 microseconds and the average duration of the preceding opposite-polarity pulses was approximately 40 microseconds. These figures are based on measurements of more than 5000 lightning flashes.
A likely explanation may lie in the fact that Nepal has regions that are a mere 60 metres above sea level and then within just 160 kilometres we can figuratively scale the giddy heights of Mount Everest, the peak at 8848 metres above sea level. Moreover across this altitude gradient and through the course of the seasons, Nepal can have a temperature ranging from a balmy 30 degrees Celsius down to –50 Celsius. All such characteristics are unique of themselves and so it is perhaps no surprise that the lightning seen in this region is unique too.
It is worth pointing out that lightening signatures not dissimilar to the unique flashes measured in Nepal have been seen occasionally in Sweden and Florida but not at anything like the frequency compared to other flashes seen in Nepal.
Pitri Bhakta Adhikari, Unique lightning signatures observed from sub-tropical, mountainous country, Nepal, International Journal of Hydrology Science and Technology (2021). DOI: 10.1504/IJHST.2021.115488
https://phys.org/news/2021-06-nepal-unique-lightning-signature-invo...
Jun 11, 2021
Dr. Krishna Kumari Challa
The digestive system of cows influences human's vitamin B12 intake
What a cow eats determines how much vitamin B12 you get from milk!
Milk is the main source of vitamin B12 consumption for many people around the world. A glass of cow’s milk contains about 46% of the daily-recommended dietary intake of vitamin B12 for adults. But what factors influence the concentration of B12 in a glass of milk? Turns out, what cows eat and how they digest it can impact human’s B12 intake.
Many plants that grow on our planet cannot be used directly by humans as food. But cows have the ability to convert these plants into proteins and vitamins humans can consume through milk. Vitamin B12 comes from animal products, produced by microorganisms in the digestive tract of cows, sheep, and goats. Cow’s milk is an excellent natural source of B12, because of the abundance of bacteria in their digestive tract capable of producing the vitamin.
Specifically, cows have a digestive system that is uniquely different from our own. Instead of a single compartment to the stomach they have four. Of the four compartments, the rumen is the largest and the main digestive center filled with billions of microorganisms that are able to break down grass and other vegetation that animals with one stomach, including humans, cannot digest.
This research has found that certain microorganisms in the rumen of cows are linked to vitamin B12 abundance. Diets higher in acid detergent fibre, such as grass, tended to encourage increased vitamin B12 concentrations in milk. Alternativity, diets higher in starch and energy concentration, based feed tended to result in lower vitamin B12 concentrations. When the pH in the rumen is lower there tends to be higher production of vitamin B12. However, we do not know at this time if vitamin B12 concentration is driving changes in the microbiome or if the microbiome is driving changes in the concentration of vitamin B12.
Animals 2021, 11(2), 532; https://doi.org/10.3390/ani11020532
https://www.mdpi.com/2076-2615/11/2/532
https://researchnews.cc/news/7168/The-digestive-system-of-cows-infl...
Jun 11, 2021
Dr. Krishna Kumari Challa
Physicists dream big with an idea for a particle collider on the moon
A lunar particle accelerator could reach 1,000 times the energy of Earth’s largest collider
A very high energy hadron collider on the Moon
A particle collider encircling the moon could reach an energy of 14 quadrillion electron volts, physicists report June 6 at arXiv.org. That’s about 1,000 times the energy of the world’s biggest particle accelerator, the Large Hadron Collider, or LHC, at CERN near Geneva.
Such a fantastical machine would probably be buried under the moon’s surface to avoid wild temperature swings, the researchers say, and could be powered by a ring of solar panels around the moon.
https://arxiv.org/abs/2106.02048
https://www.sciencenews.org/article/moon-particle-collider-accelera...
Jun 11, 2021
Dr. Krishna Kumari Challa
The mere sight of illness may kick-start a canary’s immune system
Simply seeing another bird get sick is enough to trigger an immune response in healthy birds
For canaries, just seeing their feathered friends get sick may be enough to preemptively rev up their immune systems.
Healthy birds housed within view of fellow fowl infected with a common pathogen mounted an immune response, despite not being infected themselves, researchers report online June 9 in Biology Letters.
It’s fascinating that some sort of visual cue could alter immune function.
one experiment in humans found that a mere photo of a sick person increases the activity of inflammation-stimulating chemicals called cytokines. But no one had ever looked to see whether being within eyeshot of an actually sick individual could compel the immune system to preemptive action.
In the experiments researchers conducted, as healthy birds witnessed neighbors becoming visibly sick, their immune systems stirred. A measure of the birds’ ability to burst foreign cells, called CH50 complement activity, rose in conjunction with how sick the infected birds appeared. White blood cell counts were also significantly different in birds exposed to sick individuals, rather than healthy ones. Cytokine levels did not differ between the two groups.
Blood tests showed that no healthy birds caught MG during the experiment, suggesting that some sort of external cue altered immune function. That cue was likely visual.
A.C. Love et al. Perception of infection: disease-related social cues influence immu.... Biology Letters. Published online June 9, 2021. doi: 10.1098/rsbl.2021.0125.
https://www.sciencenews.org/article/canary-immune-system-sight-illn...
Jun 11, 2021
Dr. Krishna Kumari Challa
Bodies May Treat Fast Food Like a Dangerous Infection
The immune system can respond to a fast food diet in much the same way it does to a bacterial infection, according to a 2018 study on mice, raising new questions about just how damaging regular trips to burger and pizza chains could be to our health.
Mice fed the equivalent of a "Western diet" high in saturated fats, sugar, and salt for a month, with nothing in the way of fresh fruit, vegetables, or fibre, were shown to increase the number of immune cells in their blood, just as they would if they'd been hit by a microbial infection.
What's more, this aggressive state of alarm that fast food triggers could stick around for the long term, said the international team of researchers – that's based on recent research into the way our immune systems can remember aspects of past battles they've fought.
Those white blood cells pointed the scientists towards certain genes that were activated by the mouse diets, genes containing progenitor cells – the types of cells responsible for raising up an immune cell army.
That genetic breadcrumb trail matters, because it's these progenitor cells that have previously been found to have a kind of memory in dealing with biological attack.
In other words, once the body has started to react to a fast food diet, returning to a healthy eating regime may not be enough to completely undo the changes, and that's got some implications for our overall health.
Indeed, when the mice went back to their regular cereal diet after a month, the inflammation disappeared – but the genetic reprogramming that kept the mice more sensitive to a future attack stuck around.
https://www.cell.com/cell/fulltext/S0092-8674(17)31493-9
https://www.sciencealert.com/bodies-may-treat-a-western-diet-like-a...
https://www.sciencealert.com/bodies-may-treat-a-western-diet-like-a...
Jun 11, 2021
Dr. Krishna Kumari Challa
Jun 12, 2021
Dr. Krishna Kumari Challa
New discovery shows human cells can write RNA sequences into DNA
Cells contain machinery that duplicates DNA into a new set that goes into a newly formed cell. That same class of machines, called polymerases, also build RNA messages, which are like notes copied from the central DNA repository of recipes, so they can be read more efficiently into proteins. But polymerases were thought to only work in one direction DNA into DNA or RNA. This prevents RNA messages from being rewritten back into the master recipe book of genomic DNA. Now, researchers provide the first evidence that RNA segments can be written back into DNA, which potentially challenges the central dogma in biology and could have wide implications affecting many fields of biology.
Polθ reverse transcribes RNA and promotes RNA-templated DNA repair, Science Advances (2021). DOI: 10.1126/sciadv.abf1771
https://phys.org/news/2021-06-discovery-human-cells-rna-sequences.h...
Jun 12, 2021
Dr. Krishna Kumari Challa
South African worker honeybees reproduce by making near-perfect clones of themselves
A team of researchers has found that workers in a species of honeybee found in South Africa reproduce by making near-perfect clones of themselves.
Prior research has found that some creatures reproduce through parthenogenesis, in which individuals reproduce without mating. This form of reproduction has the advantage of not wasting time and energy on mating and the gene pool remains undiluted. The downside, of course, is loss of genetic diversity, which helps species survive in changing conditions. Prior research has also shown that for most species, parthenogenesis is a less-than-perfect way to produce offspring. This is because some tiny bit of genetic material is generally mixed wrong—these mistakes, known as recombinations, can lead to birth defects or non-productive eggs. In this new effort, the researchers have found a kind of honeybee that has developed a way to avoid recombinations.
The researchers found that South African Cape honeybee queens reproduce sexually, but the workers reproduce asexually.
They then conducted a small experiment—they affixed tape to the reproductive organs of a queen, preventing males from mating with her, and then allowed both her and the worker bees in the same hive to reproduce asexually. They then tested the degree of recombination in both. They found that offspring of the queen had approximately 100 times as much recombination as the worker bees. Even more impressive, the offspring of the worker bees were found to be nearly identical clones of their parent. More testing showed that one line of worker bees in the hive had been cloning themselves for approximately 30 years—a clear sign that workers in the hive were not suffering from birth defects or an inability to produce viable offspring. It also showed that they have evolved a means for preventing recombination when they reproduce. The researchers note that despite their unique abilities, the bees are still in line with evolutionary theory—they are simply doing what works best for their continued existence.
Benjamin P. Oldroyd et al, Adaptive, caste-specific changes to recombination rates in a thelytokous honeybee population, Proceedings of the Royal Society B: Biological Sciences (2021). DOI: 10.1098/rspb.2021.0729
https://phys.org/news/2021-06-south-african-worker-honeybees-near-p...
Jun 12, 2021
Dr. Krishna Kumari Challa
Russel's Tea pot and the thought experiment
A quick explanation of Russell's Teapot, a thought experiment demonstrating that the burden of proof rests on the claimant.
Jun 14, 2021
Dr. Krishna Kumari Challa
A 36-year-old woman in South Africa with HIV carried Covid for 216 days, during which Covid viruses accumulated 32 mutations - 13 to the spike protein (could help Covid viruses escape immune responses).
If more such cases are found, it raises the prospect that HIV infection could be a source of new variants simply because the patients could carry the virus for longer.
Scientists only spotted this case because she was enrolled in a study of 300 people with HIV looking at their immune response to Covid.
The researchers also found that four other people with HIV had carried the coronavirus for longer than a month.
…there have been reported cases of people with kidney transplants testing positive for almost a year.
The finding could be of particular importance for Africa, which had about 26 million people living with HIV in 2020. The WHO on Friday warned that a sharp rise in COVID-19 cases could turn into a continentwide third wave of Covid.
https://www.krisp.org.za/publications.php?pubid=336
https://www.businessinsider.in/science/news/a-woman-with-hiv-had-th...
Jun 14, 2021
Dr. Krishna Kumari Challa
Dark matter is slowing the spin of the Milky Way's galactic bar
The spin of the Milky Way's galactic bar, which is made up of billions of clustered stars, has slowed by about a quarter since its formation, according to a new study by researchers.
For 30 years, astrophysicists have predicted such a slowdown, but this is the first time it has been measured.
The researchers say it gives a new type of insight into the nature of dark matter, which acts like a counterweight slowing the spin.
Researchers analysed Gaia space telescope observations of a large group of stars, the Hercules stream, which are in resonance with the bar—that is, they revolve around the galaxy at the same rate as the bar's spin.
These stars are gravitationally trapped by the spinning bar. The same phenomenon occurs with Jupiter's Trojan and Greek asteroids, which orbit Jupiter's Lagrange points (ahead and behind Jupiter). If the bar's spin slows down, these stars would be expected to move further out in the galaxy, keeping their orbital period matched to that of the bar's spin.
The researchers found that the stars in the stream carry a chemical fingerprint—they are richer in heavier elements (called metals in astronomy), proving that they have traveled away from the galactic center, where stars and star-forming gas are about 10 times as rich in metals compared to the outer galaxy.
Using this data, the team inferred that the bar—made up of billions of stars and trillions of solar masses—had slowed down its spin by at least 24% since it first formed.
The counterweight slowing this spin must be dark matter. Until now, researchers have only been able to infer dark matter by mapping the gravitational potential of galaxies and subtracting the contribution from visible matter.
This new research provides a new type of measurement of dark matter—not of its gravitational energy, but of its inertial mass (the dynamical response), which slows the bar's spin.
Rimpei Chiba et al, Tree-ring structure of Galactic bar resonance, Monthly Notices of the Royal Astronomical Society (2021). DOI: 10.1093/mnras/stab1094
https://phys.org/news/2021-06-dark-milky-galactic-bar.html?utm_sour...
Jun 15, 2021
Dr. Krishna Kumari Challa
Microbes in ocean play important role in moderating Earth's temperature
Methane is a strong greenhouse gas that plays a key role in Earth's climate. Anytime we use natural gas, whether we light up our kitchen stove or barbeque, we are using methane.
Only three sources on Earth produce methane naturally: volcanoes, subsurface water-rock interactions, and microbes. Between these three sources, most is generated by microbes, which have deposited hundreds of gigatons of methane into the deep seafloor. At seafloor methane seeps, it percolates upwards toward the open ocean, and microbial communities consume the majority of this methane before it reaches the atmosphere. Over the years, researchers are finding more and more methane beneath the seafloor, yet very little ever leaves the oceans and gets into the atmosphere. Where is the rest going?
A team of researchers now discovered that microbial communities that rapidly consume the methane, preventing its escape into Earth's atmosphere. The study published in Proceedings of the National Academy of Sciences collected and examined methane-eating microbes from seven geologically diverse seafloor seeps and found, most surprisingly, that the carbonate rocks from one site in particular hosts methane-oxidizing microbial communities with the highest rates of methane consumption measured to date.
The microbes in these carbonate rocks are acting like a methane bio filter consuming it all before it leaves the ocean.
Jeffrey J. Marlow el al., "Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2006857118
https://phys.org/news/2021-06-microbes-ocean-important-role-moderat...
Jun 15, 2021
Dr. Krishna Kumari Challa
Deposits of Copper And Magnetic Iron Found in Alzheimer's Patients'...
Scarce as they are, copper and iron metals are necessary for our survival, playing essential roles in human growth and metabolism. But one place we wouldn't expect to find either is clumped inside our brain cells.
However, for people with the neurodegenerative disorder Alzheimer's disease, something seems to be turning these elements into microscopic ingots.
A team of researchers from the US and UK spotted the tell-tale glint of copper and iron in their elemental forms using a form of X-ray microscopy (STXM) on samples of neural plaques taken from the frontal and temporal lobes of Alzheimer's patients.
Plaques are a typical feature of this particular form of dementia, made up of proteins broken down into what's known as beta-amyloid.
Yet therapies focused on clearing clumps of beta-amyloid from the brain haven't led us much closer to a treatment for Alzheimer's, leaving researchers wondering what role – if any – they play in the disease's progress.
Ongoing research has continued to build a picture surrounding the biology that could be responsible for the plaques, with researchers looking at their formation and taste for destruction from every angle.
One angle that hasn't been fully explored is the toxic effect of biomineralization, or the accumulation of minerals such as hematite in brain cells.
Trapped as a charged ionic form inside hemoglobin, iron is a handy way to transport oxygen around the body. And few places are as desperate for oxygen as the human brain.
Once released from its protein shackles, however, iron shows its nasty side as what's known as its labile form, generating reactive species of oxygen that wreak havoc on delicate biochemistry and destroying cells.
High levels of labile iron have been linked to neurodegenerative disorders like Alzheimer's before. Similarly, copper is another mineral typically shielded safely in a protein, yet thoroughly capable of making a mess of our brains in labile form.
https://advances.sciencemag.org/content/7/24/eabf6707
https://www.sciencealert.com/scientists-identify-deposits-of-copper...
Jun 15, 2021
Dr. Krishna Kumari Challa
New treatment stops progression of Alzheimer's disease in monkey brains
A new therapy prompts immune defense cells to swallow misshapen proteins, amyloid beta plaques and tau tangles, whose buildup is known to kill nearby brain cells as part of Alzheimer's disease, a new study shows.
Led by researchers at NYU Grossman School of Medicine, the investigation showed that elderly monkeys had up to 59 percent fewer plaque deposits in their brains after treatment with CpG oligodeoxynucleotides (CpG ODN), compared with untreated animals. These amyloid beta plaques are protein fragments that clump together and clog the junctions between nerve cells (neurons).
Brains of treated animals also had a drop in levels of toxic tau. This nerve fiber protein can destroy neighboring tissue when disease-related changes to its chemical structure causes it to catch on other cells.
https://medicalxpress.com/news/2021-06-treatment-alzheimer-disease-...
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Jun 16, 2021
Dr. Krishna Kumari Challa
Study finds association between head impacts and imaging changes in youth football players
A new study shows that head impacts experienced during practice are associated with changes in brain imaging of young players over multiple seasons.
A group of 16 youth athletes who participated in non-contact sports, such as swimming, tennis and track, served as the control group in the study.
Pre- and post-season MRIs were completed for both groups of study participants using diffusion tensor imaging (DTI), a type of neuroimaging that can be used to assess the integrity of the brain's white matter, indicating possible sites of injury.
In addition, the research team gathered biomechanical data of linear and rotational head accelerations of head impacts from the football group during all practice and games via the Riddell Head Impact Telemetry System in the helmets. That information was transmitted in real time to a sideline data collection field unit for later analysis.
In 19 of the 47 youth football athletes, brain images were obtained pre- and post-season for two consecutive football seasons. Using data from the DTIs and the head impact telemetry system, the researchers found variations in head impact exposures (i.e., the number and severity of head impacts measured) from year-to-year and between athletes. For example, in an examination of data from three consecutive seasons, some youths experienced more impacts in their second year of play than in their first, while other youths experienced fewer impacts in later years of play.
They observed variability in the amount and direction of imaging changes in the brain related to the amount of exposure that the players experienced on the field. If efforts are taken to reduce that exposure on-field, changes in brain imaging can be potentially mitigated.
These findings further support ongoing efforts to reduce the number of head impacts in football practices.
Journal of Neurosurgery: Pediatrics, thejns.org/doi/full/10.3171/2021.1.PEDS20586
https://medicalxpress.com/news/2021-06-association-impacts-imaging-...
Jun 16, 2021
Dr. Krishna Kumari Challa
Combining classical and quantum computing opens door to new discoveries
Researchers have discovered a new and more efficient computing method for pairing the reliability of a classical computer with the strength of a quantum system.
This new computing method opens the door to different algorithms and experiments that bring quantum researchers closer to near-term applications and discoveries of the technology.
In the future, quantum computers could be used in a wide variety of applications including helping to remove carbon dioxide from the atmosphere, developing artificial limbs and designing more efficient pharmaceuticals.
The research team is the first to propose the measurement-based approach in a feedback loop with a regular computer, inventing a new way to tackle hard computing problems. Their method is resource-efficient and therefore can use small quantum states because they are custom-tailored to specific types of problems.
Hybrid computing, where a regular computer's processor and a quantum co-processor are paired into a feedback loop, gives researchers a more robust and flexible approach than trying to use a quantum computer alone.
While researchers are currently building hybrid, computers based on quantum gates, this research team was interested in the quantum computations that could be done without gates. They designed an algorithm in which a hybrid quantum-classical computation is carried out by performing a sequence of measurements on an entangled quantum state.
The team's theoretical research is good news for quantum software developers and experimentalists because it provides a new way of thinking about optimization algorithms. The algorithm offers high error tolerance, often an issue in quantum systems, and works for a wide range of quantum systems, including photonic quantum co-processors.
R. R. Ferguson et al, Measurement-Based Variational Quantum Eigensolver, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.220501
https://phys.org/news/2021-06-combining-classical-quantum-door-disc...
Jun 16, 2021
Dr. Krishna Kumari Challa
Scientists discover unreported plant body part
A previously unreported anatomical structure named the 'cantil' has been described in the popular plant model, Arabidopsis thaliana. Scientists reveal that the cantil forms between the stem and flower-bearing stalk when flowering is delayed. Published in the journal Development, this study highlights that there are still discoveries to be made, even in some of the most meticulously studied species, and provides new clues for understanding conditional growth in plants.
Cantils are rare; they only develop under certain conditions that cause the plant to delay flowering, such as short day lengths, and cantils only form at the precise point at which the plant begins to flower.
However, some popular Arabidopsis strains have genetic mutations that make them incapable of producing cantils at all.
Gookin, T. E. and Assmann, S. M. (2021). Cantil: a previously unreported organ in wild-type Arabidopsis regulated by FT, ERECTA and heterotrimeric G proteins. Development, 148, dev195545. DOI: 10.1242/dev.195545
https://phys.org/news/2021-06-scientists-unreported-body.html?utm_s...
Jun 16, 2021
Dr. Krishna Kumari Challa
The electron merry-go-round: Researchers find new mechanism for cla...
Photoemission is a property of metals and other materials that emit electrons when struck by light. Electron emission after light absorption was already explained by Albert Einstein. But since this effect is a highly complex process, scientists have still not been able to fully elucidate its details. Prof. Dr. Bernd von Issendorff and his team at the University of Freiburg's Institute of Physics have now succeeded in detecting a previously unknown quantum effect in the angular distributions of photoelectrons from cryogenic mass-selected metal clusters. The angular distributions resemble those of classical particles, a behavior that is surprisingly explainable by the strong electron-electron interaction in these many-electron systems. The researchers published this finding in the current issue of Physical Review Letters.
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Use of PFAS in cosmetics 'widespread,' new study finds
Many cosmetics sold in the United States and Canada likely contain high levels of per- and polyfluoroalkyl substances (PFAS), a potentially toxic class of chemicals linked to a number of serious health conditions, according to new research from the University of Notre Dame.
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Study: Half of US cosmetics contain toxic chemicals
More than half the cosmetics sold in the United States and Canada likely contain high levels of a toxic industrial compound linked to serious health conditions, including cancer and reduced birth weight, according to a new study.
Jun 16, 2021
Dr. Krishna Kumari Challa
Use of PFAS in cosmetics 'widespread,' new study finds
Many cosmetics sold in the United States and Canada likely contain high levels of per- and polyfluoroalkyl substances (PFAS), a potentially toxic class of chemicals linked to a number of serious health conditions, according to new research from the University of Notre Dame.
Scientists tested more than 200 cosmetics including concealers, foundations, eye and eyebrow products and various lip products. According to the study, 56 percent of foundations and eye products, 48 percent of lip products and 47 percent of mascaras tested were found to contain high levels of fluorine, which is an indicator of PFAS use in the product. The study was recently published in the journal of Environmental Science and Technology Letters.
There's the individual risk—these are products that are applied around the eyes and mouth with the potential for absorption through the skin or at the tear duct, as well as possible inhalation or ingestion. PFAS is a persistent chemcial—when it gets into the bloodstream, it stays there and accumulates. There's also the additional risk of environmental contamination associated with the manufacture and disposal of these products, which could affect many more people.
Studies have linked certain PFAS to kidney cancer, testicular cancer, hypertension, thyroid disease, low birth weight and immunotoxicity in children.
Heather D. Whitehead et al, Fluorinated Compounds in North American Cosmetics, Environmental Science & Technology Letters (2021). DOI: 10.1021/acs.estlett.1c00240
https://phys.org/news/2021-06-pfas-cosmetics-widespread.html?utm_so...
Jun 16, 2021
Dr. Krishna Kumari Challa
Surprise volcanic eruption: Lessons from Kilauea 2018
Jun 16, 2021
Dr. Krishna Kumari Challa
New material could remove respiratory droplets from air
Although plexiglass barriers are seemingly everywhere these days—between grocery store lanes, around restaurant tables and towering above office cubicles—they are an imperfect solution to blocking virus transmission.
Instead of capturing virus-laden respiratory droplets and aerosols, plexiglass dividers merely deflect droplets, causing them to bounce away but remain in the air. To enhance the function of these protective barriers, Northwestern University researchers have developed a new transparent material that can capture droplets and aerosols, effectively removing them from air.
The material is a clear, viscous liquid that can be painted onto any surface, including plastic, glass, wood, metal, stainless steel, concrete and textiles. When droplets collide with the coated surface, they stick to it, get absorbed and dry up. The coating also is compatible with antiviral and antimicrobial materials, so sanitizing agents, such as copper, could be added to the formula.
Chem, Huang et al.: "Droplet-capturing Coatings on Environmental Surfaces Based on Cosmetic Ingredients" DOI: 10.1016/j.chempr.2021.05.017 , www.cell.com/chem/fulltext/S2451-9294(21)00266-7
https://phys.org/news/2021-06-material-respiratory-droplets-air.htm...
Jun 17, 2021
Dr. Krishna Kumari Challa
Genetically engineered nanoparticle delivers dexamethasone directly to inflamed lungs
Nanoengineers at the University of California San Diego have developed immune cell-mimicking nanoparticles that target inflammation in the lungs and deliver drugs directly where they're needed. As a proof of concept, the researchers filled the nanoparticles with the drug dexamethasone and administered them to mice with inflamed lung tissue. Inflammation was completely treated in mice given the nanoparticles, at a drug concentration where standard delivery methods did not have any efficacy.
What's special about these nanoparticles is that they are coated in a cell membrane that's been genetically engineered to look for and bind to inflamed lung cells. They are the latest in the line of so-called cell membrane-coated nanoparticles.
But while these previous cell membranes were naturally derived from the body's cells, the cell membranes used to coat this dexamethasone-filled nanoparticle were not.
"In this paper, researchers used a genetic engineering approach to edit the surface proteins on the cells before we collected the membranes. This significantly advanced our technology by allowing us to precisely overexpress certain functional proteins on the membranes or knockout some undesirable proteins.
"Genetically engineered cell membrane–coated nanoparticles for targeted delivery of dexamethasone to inflamed lungs" Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abf7820
https://phys.org/news/2021-06-genetically-nanoparticle-dexamethason...
Jun 17, 2021
Dr. Krishna Kumari Challa
Giant Rats Are Sniffing Out Landmines and Tuberculosis
These 2-foot giant pouched rats are giving rats a good name. Referred to as 'Hero Rats', they have a superpower that's saving thousands of lives: a powerful nose that can detect unexploded landmines and Tuberculosis. And now, they're being trained to sniff out just about anything, from illegal wildlife trafficking to humans trapped under rubble after a natural disaster.
Jun 18, 2021
Dr. Krishna Kumari Challa
Physicists bring human-scale object to near standstill, reaching a quantum state
To the human eye, most stationary objects appear to be just that—still, and completely at rest. Yet if we were handed a quantum lens, allowing us to see objects at the scale of individual atoms, what was an apple sitting idly on our desk would appear as a teeming collection of vibrating particles, very much in motion.
In the last few decades, physicists have found ways to super-cool objects so that their atoms are at a near standstill, or in their "motional ground state." To date, physicists have wrestled small objects such as clouds of millions of atoms, or nanogram-scale objects, into such pure quantum states.
Now for the first time, scientists at MIT and elsewhere have cooled a large, human-scale object to close to its motional ground state. The object isn't tangible in the sense of being situated at one location, but is the combined motion of four separate objects, each weighing about 40 kilograms. The "object" that the researchers cooled has an estimated mass of about 10 kilograms, and comprises about 1x1026, or nearly 1 octillion, atoms.
The researchers took advantage of the ability of the Laser Interfrometer Gravitational-wave Observatory (LIGO) to measure the motion of the masses with extreme precision and super-cool the collective motion of the masses to 77 nanokelvins, just shy of the object's predicted ground state of 10 nanokelvins.
Their results, appearing today in Science, represent the largest object to be cooled to close to its motional ground state. The scientists say they now have a chance to observe the effect of gravity on a massive quantum object.
C. Whittle el al., "Approaching the motional ground state of a 10-kg object," Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abh2634
https://phys.org/news/2021-06-physicists-human-scale-standstill-qua...
Jun 18, 2021
Dr. Krishna Kumari Challa
Giant spider webs blanket Australian landscape after heavy rainfall
Stunning photographs of vast, ghostly spider webs blanketing the flood-affected region of Gippsland in Victoria have gone viral online, prompting many to muse on the wonder of nature.
But what's going on here? Why do spiders do this after floods and does it happen everywhere?
The answer is: these webs have nothing to do with spiders trying to catch food. Spiders often use silk to move around and in this case are using long strands of web to escape from waterlogged soil.
When these flood events happen, they need evacuate quickly up out of holes they live in underground. They come out en masse and use their silk to help them do that.
You'll often see juvenile spiders let out a long strand of silk which is caught by the wind and lifted up. The web catches onto another object such as a tree and allows the spider to climb up.
That's how baby spiders (spiderlings!) disperse when they emerge from their egg sacs – it's called ballooning. They have to disperse as quickly as possible because they are highly cannibalistic so they need to move away from each other swiftly and find their own sites to hunt or build their webs.
https://www.sciencealert.com/spiders-have-cloaked-an-australian-cou...
Jun 18, 2021
Dr. Krishna Kumari Challa
Bacteria can recover precious metals from electric vehicle batteries
Bioleaching, also called biomining, employs microbes which can oxidise metal as part of their metabolism. It has been widely used in the mining industry, where microorganisms are used to extract valuable metals from ores. More recently, this technique has been used to clean up and recover materials from electronic waste, particularly the printed circuit boards of computers, solar panels, contaminated water and even uranium dumps.
All metals present in EV batteries can be recovered using bioleaching. Bacteria like Acidithiobacillus ferrooxidans and other non-toxic species target and recover the metals individually without the need for high temperatures or toxic chemicals. These purified metals constitute chemical elements, and so can be recycled indefinitely into multiple supply chains.
Scaling up bioleaching involves growing bacteria in incubators at 37°C, often using carbon dioxide. Not a lot of energy is needed, so the process has a much smaller carbon footprint than typical recycling plants, while also contributing less pollution. While reducing EV battery waste, bioleaching facilities mean manufacturers can recover these precious metals locally, and rely less on the few producer countries.
EV batteries are a technology still in their infancy. The reuse of their components should be considered as part of their design. Rather than remaining an afterthought, recycling can become both the beginning and end of an EV battery’s life cycle with bioleaching, producing high-quality raw materials for new batteries at low environmental cost.
https://theconversation.com/bacteria-can-recover-precious-metals-fr...
Jun 19, 2021