In our study, we used publicly available data, taken by theHubble Space Telescope, to obtain the eclipse spectrum of this planet.
We then used open-source software to extract the presence of molecules and found there were plenty of metals (made from molecules). This discovery is interesting as it was previously thought that these molecules would not be present at such extreme temperatures – they would be broken apart into smaller compounds.
Subject to the strong gravitational pull from its host star, Kelt-9 b is “tidally locked”, which means that the same face of the planet permanently faces the star. This results in a strong temperature difference between the planet’s day and night sides. As the eclipse observations probe the hotter day-side, we suggested that the observed molecules could in fact be dragged by dynamic processes from the cooler regions, such as the night-side or from deeper in the interior of the planet. These observations suggest that the atmospheres of these extreme worlds are ruled by complex processes that are poorly understood.
Kelt-9 b is interesting because of its inclined orbit of about 80 degrees. This suggests a violent past, with possible collisions, which in fact is also seen for many other planets of this class. It is most likely that this planet formed away from its parent star and that the collisions happened as it migrated inwards toward the star. This supports the theory that large planets tend to form away from their host star in proto-stellar disks – which give rise to solar systems – capturing gaseous and solid materials as they migrate toward their star.
Physicists measure smallest gravitational field yet
Physicists in Austria have measured the gravitational field from the smallest ever object: a gold sphere with a diameter of just 2 mm. Carried out using a miniature torsion balance, the measurement paves the way to even more sensitive gravitational probes that could reveal gravity’s quantum nature.
The latest work, in contrast, uses a gold sphere with a mass of just 92 mg as its source.Markus AspelmeyerandTobias Westphalof theInstitute for Quantum Optics and Quantum Informationin Vienna and colleagues positioned this mass a few millimetres away from another tiny gold sphere with about the same mass located at one end of a 4 cm-long glass rod. The rod was suspended at its centre via a silica fibre, while a third sphere at the far end of the rod acted as a counterbalance.
Such “torsion balances” have been used for more than 200 years to make precise measurements of gravity. The idea is that the source mass pulls the near end of the bar towards itself, causing the suspending fibre or wire to rotate. By measuring this rotation and balancing it against the stiffness of the wire, the strength of the gravitational interaction can be calculated. The fact that the bar moves horizontally means it is less exposed to the far larger gravitational field of the Earth.
A major challenge with such experiments is screening out noise. Aspelmeyer and colleagues did this by placing the balance in a vacuum to limit acoustic and thermal interference, while also grounding the source mass and placing a Faraday shield between it and the test mass to reduce electromagnetic interactions. In addition, they mainly collected data at night to minimize ambient sources of gravity. This is important because the gravitational attraction of the source mass is equivalent to the pull of a person standing 2.5 m from the experiment or a Vienna tram 50 m away.
To generate signals above the remaining noise, the researchers used a bending piezoelectric device to cyclically move the source towards and away from the test mass. Doing this at a fixed frequency (12.7 mHz) allowed them to look for a corresponding variation in the rotation of the balance – which they measured by bouncing a laser beam off a mirror below the silica fibre.
After repeating this process hundreds of times over a 13.5-hour period and then converting the time-series data into a frequency spectrum, Aspelmeyer and colleagues identified two clear signals above the background. These were the principle oscillation at 12.7 mHz and, at 25.4 mHz, the second harmonic generated by the gravitational field’s nonlinear variation in space. As the researchers point out, both harmonics were well above the resonant frequency of the oscillating balance and below the frequencies of readout noise.
A huge neutrino detector in the Antarctic ice sheet might have seen the first evidence of a rare neutrino-interaction process called the Glashow resonance.
The IceCube Neutrino Observatory, buried in the deep ice near the Amundsen–Scott South Pole Station, observes eye-wateringly powerful neutrinos produced by sources such as active galactic nuclei and supernovae. The observatory detected a shower of secondary particles that look likely to have been caused by a collision between an electron antineutrino travelling close to th.... If confirmed by more observations, the finding provides further confirmation of the standard model of particle physics, proves the existence of cosmic antineutrinos and opens the door to a better understanding of the wild stuff going on in the cosmos.
Membrane around tumors may be key to preventing metastasis
For cancer cells to metastasize, they must first break free of a tumors own defenses. Most tumors are sheathed in a protective basement membrane a thin, pliable film that holds cancer cells in place as they grow and divide. Before spreading to other parts of the body, the cells must breach the basement membrane, a material that itself has been tricky for scientists to characterize. Now MIT engineers have probed the basement membrane of breast cancer tumors and found that the seemingly delicate coating is as tough as plastic wrap, yet surprisingly elastic like a party balloon, able to inflate to twice its original size. But while a balloon becomes much easier to blow up after some initial effort, the team found that a basement membrane becomes stiffer as it expands. This stiff yet elastic quality may help basement membranes control how tumors grow.
The fact that the membranes appear to stiffen as they expand suggests that they may restrain a tumor’s growth and potential to spread, or metastasize, at least to a certain extent.
The findings, published this week in the Proceedings of the National Academy of Sciences, may open a new route toward preventing tumor metastasis, which is the most common cause of cancer-related deaths.
Now scientists can think of ways to add new materials or drugs to further enhance this stiffening effect, and increase the toughness of the membrane to prevent cancer cells from breaking through
Sonolithography: In‐Air Ultrasonic Particulate and Droplet Patterning
Sonolithography is based on the application of acoustic radiation forces arising from the interference of ultrasonic standing waves to direct airborne particle/droplet accumulation. Sonolithography is capable of rapidly patterning micrometer to millimeter scale materials onto a wide variety of substrates over a macroscale (cm2) surface area and can be used for both indirect and direct cell patterning.
I ain't afraid of no ghosts: people with mind-blindness not so easily spooked
People with aphantasia – that is, the inability to visualise mental images – are harder to spook with scary stories, a new UNSW Sydney study shows.
The study, published today in Proceedings of the Royal Society B, tested how aphantasic people reacted to reading distressing scenarios, like being chased by a shark, falling off a cliff, or being in a plane that’s about to crash.
The researchers were able to physically measure each participant’s fear response by monitoring changing skin conductivity levels – in other words, how much the story made a person sweat. This type of test is commonly used in psychology research to measure the body’s physical expression of emotion.
According to the findings, scary stories lost their fear factor when the readers couldn’t visually imagine the scene – suggesting imagery may have a closer link to emotions than scientists previously thought.
Researchers found the strongest evidence yet that mental imagery plays a key role in linking thoughts and emotions.
Aphantasia affects 2-5 per cent of the population, but there is still very little known about the condition.
A UNSW study published last year found that aphantasia is linked to a widespread pattern of changes to other cognitive processes, like remembering, dreaming and imagining.
Three Ways Quantum Physics Affects Your Daily Life
Quantum physics is all around us. The universe as we know it runs on quantum rules, and while the classical physics that emerges when you apply quantum physics to enormously huge numbers of particles seem very different, there are lots of familiar, everyday phenomena that owe their existence to quantum effects. Here are a few examples of things you probably run into in your everyday life without realizing that they're quantum:
Toasters: The red glow of a heating element as you toast a slice of bread or a bagel is a very familiar sight for most of us. It's also the place where quantum physics got its start: Explaining why hot objects glow that particular color of red is the problem that quantum physics was invented to solve.
"quantum hypothesis" (giving the eventual theory its name) that the light could only be emitted in discrete chunks of energy, integer multiples of a small constant times the frequency of the light. For high-frequency light, this energy quantum is larger than the share of heat energy allotted to that frequency, and thus no light is emitted at that frequency. This cuts off the high-frequency light, and leads to a formula that matches the observed spectrum of light from hot objects to great precision.
So, every time you toast bread, you're looking at the place where quantum physics got its start.
Fluorescent Lights: Old-school incandescent light bulbs make light by getting a piece of wire hot enough to emit a bright white glow, which makes them quantum in the same way that a toaster is. If you have fluorescent bulbs around-- either the long tubes or the newer twisty CFL bulbs, you're getting light from another revolutionary quantum process.
Computers: While Bohr's quantum model was undeniably useful, it didn't initially come with a physical reason as to why there should be special states for electrons within atoms. That didn't come for almost ten years, but once the idea got locked it, it turned out to be the basis for the most transformative technological revolution of the last century.
So, every time you turn on your computer (say, to read a blog post about quantum physics), you're exploiting the wave nature of electrons, and the unprecedented control of materials that allows. It may not be the sexy kind of quantum computer, but every modern computer needs quantum physics to work properly.
Scientists have long theorized that supermassive black holes can wander through space—but catching them in the act has proven difficult. Now, researchers at the Center for Astrophysics | Harvard & Smithsonian have identified the clearest case to date of a supermassive black hole in motion. Their results are published today in the Astrophysical Journal.
We don't expect the majority of supermassive black holes to be moving; they're usually content to just sit around. They're just so heavy that it's tough to get them going. Consider how much more difficult it is to kick a bowling ball into motion than it is to kick a soccer ball—realizing that in this case, the 'bowling ball' is several million times the mass of our Sun. That's going to require a pretty mighty kick.
Usually the velocities of the black holes the same as the velocities of the galaxies they reside in. We expect them to have the same velocity. If they don't, that implies the black hole has been disturbed.
For their search, the team initially surveyed 10 distant galaxies and the supermassive black holes at their cores. They specifically studied black holes that contained water within their accretion disks—the spiral structures that spin inward towards the black hole.
As the water orbits around the black hole, it produces a laser-like beam of radio light known as a maser. When studied with a combined network of radio antennas using a technique known as very long baseline interferometry (VLBI), masers can help measure a black hole's velocity very precisely.
The technique helped the team determine that nine of the 10 supermassive black holes were at rest—but one stood out and seemed to be in motion.
Located 230 million light-years away from Earth, the black hole sits at the center of a galaxy named J0437+2456. Its mass is about three million times that of our Sun.
Using follow-up observations with the Arecibo and Gemini Observatories, the team has now confirmed their initial findings. The supermassive black hole is moving with a speed of about 110,000 miles per hour inside the galaxy J0437+2456.
But what's causing the motion is not known. The team suspects there are two possibilities.
We may be observing the aftermath of two supermassive black holes merging. The result of such a merger can cause the newborn black hole to recoil, and we may be watching it in the act of recoiling or as it settles down again.
But there's another, perhaps even more exciting possibility: the black hole may be part of a binary system.
Further observations, however, will ultimately be needed to pin down the true cause of this supermassive black hole's unusual motion.
Dominic W. Pesce et al, A Restless Supermassive Black Hole in the Galaxy J0437+2456, The Astrophysical Journal (2021). DOI: 10.3847/1538-4357/abde3d
Accurate aging of wild animals thanks to first epigenetic clock for bats
A new study by researchers found that DNA from tissue samples can be used to accurately predict the age of bats in the wild. The study also showed age-related changes to the DNA of long-lived species are different from those in short-lived species, especially in regions of the genome near genes associated with cancer and immunity. This work provides new insight into causes of age-related declines.
This is the first research paper to show that animals in the wild can be accurately aged using an epigenetic clock, which predicts age based on specific changes to DNA. This work provides a new tool for biologists studying animals in the wild. In addition, the results provide insight into possible mechanisms behind the exceptional longevity of many bat species. The study appears in the March 12, 2021, issue of the journal Nature Communications.
The researchers looked at DNA from 712 bats of known age, representing 26 species, to find changes in DNA methylation at sites in the genome known to be associated with aging. DNA methylation is a process that switches genes off. It occurs throughout development and is an important regulator for cells. Overall, methylation tends to decrease throughout the genome with age. Using machine learning to find patterns in the data, the researchers found that they could estimate a bat's age to within a year based on changes in methylation at 160 sites in the genome. The data also revealed that very long-lived bat species exhibit less change in methylation overall as they age than shorter-lived bats.
Gerald S. Wilkinson, Danielle M. Adams, Amin Haghani, Ake T. Lu, Joseph Zoller, Charles E. Breeze, Bryan D. Arnold, Hope C. Ball, Gerald G. Carter, Lisa Noelle Cooper, Dina K. N. Dechmann, Paolo Devanna, Nicolas J. Fasel, Alexander V. Galazyuk, Linus Günther, Edward Hurme, Gareth Jones, Mirjam Knörnschild, Ella Z. Lattenkamp, Caesar Z. Li, Frieder Mayer, Josephine A. Reinhardt, Rodrigo A. Medellin, Martina Nagy, Brian Pope, Megan L. Power, Roger D. Ransome, Emma C. Teeling, Sonja C. Vernes, Daniel Zamora-Mejías, Joshua Zhang, Paul A. Faure, Lucas J. Greville, Steve Horvath.DNA methylation predicts age and provides insight into exceptional longevity of bats.Nature Communications, 2021; 12 (1) DOI:10.1038/s41467-021-21900-2
A pioneering study led by University of Saskatchewan (USask) veterinary ophthalmologist Dr. Marina Leis (DVM, DACVO) shows that bacterial communities vary on different parts of the eye surface—a finding that significantly alters understanding of the mechanisms of eye disease and can lead to developing new treatments.
A study led by the Monash Institute of Pharmaceutical Sciences and the Florey Institute of Neuroscience and Mental Health uncovered a potential therapeutic target to treat alcohol use disorder (AUD) by targeting a specific receptor in the brain. The researchers found that by targeting the muscarinic M4 receptor in the brain, both habitual drinking and the likelihood to relapse could be improved in those suffering from alcohol addiction.
The team performed genome-wide RNA sequencing and protein expression studies in human tissue samples from people with AUD and non-drinkers to identify potential therapeutic targets.
Scientists Find a Natural Protein That Stops Allergies And Autoimmune Conditions
It's called neuritin.
Using transgenic mice and cultures of cells taken from human tonsils, researchers have now found evidence of how our bodies might defend against the mistakes that result in conditions such as asthma, food allergies, and lupus. They found a protein called neuritin, produced by immune cells. It acts a bit like an inbuilt, boss-level antihistamine.
Neuritin suppresses formation of rogue plasma cells which are the cells that produce harmful antibodies.
Faster-Than-Light Travel Is Possible Within Einstein's Physics, Astrophysicist Shows
Physicists are not the kind of people who give up easily, though. Give them an impossible dream, and they'll give you an incredible, hypothetical way of making it a reality. Maybe.
In anew studyby physicist Erik Lentz from Göttingen University in Germany, we may have a viable solution to the dilemma, and it's one that could turn out to be more feasible thanother would-be warp drives.
This is an area that attractsplenty of bright ideas, each offering a different approach to solving the puzzle offaster-than-lighttravel: achieving a means of sending something across space at superluminal speeds.
There are some problems with this notion, however. Within conventional physics, in accordance with Albert Einstein's theories of relativity, there's no real wayto reach or exceed the speed of light, which is something we'd need for any journey measured in light-years.
That hasn't stopped physicists from trying to break this universal speed limit, though.
While pushing matter past the speed of light will always be a big no-no, spacetime itself has no such rule. In fact, the far reaches of the Universe are already stretching away faster than its light could ever hope to match.
To bend a small bubble of space in a similar fashion for transport purposes, we'd need to solve relativity's equations to create a density of energy that's lower than the emptiness of space. While this kind ofnegative energyhappens on a quantum scale, piling up enough in the form of 'negative mass' is still a realm for exotic physics.
In addition to facilitating other kinds of abstract possibilities, such as wormholes and time travel, negative energy could help power what's known as theAlcubierre warp drive.
This speculative concept would make use of negative energy principles to warp space around a hypothetical spacecraft, enabling it to effectively travel faster than light without challenging traditional physical laws, except for the reasons explained above, we can't hope to provide such a fantastical fuel source to begin with.
Skin-immersion study shows serious damage after 12 hours in water A new study from Binghamton University researchers could change the way that medical professionals and scientists think about the long-term effects of skin immersion in water.
Researchers tested samples of stratum corneum (the outer layer of human skin) from subjects 27 to 87 years old.
After 12 hours of immersion, the skin loses plasticity because of reduced ability to hold water. It also depletes both lipids and natural moisturizing factors, which can lead to long-term problems.
Essity, a global hygiene and health firm based on Sweden, helped to fund the study and assisted in the research to better understand skin damage caused by diaper dermatitis, when infants or incontinent adults are not regularly changed. the findings have implications in a variety of different fields, including cryo-preservation, organ transport for transplantation, divers’ health, forensics and various foot-immersion syndromes. https://pdf.sciencedirectassets.com/271007/1-s2.0-S0022202X73X90005...
In 1966, US Army scientists drilled down through nearly a mile of ice in northwestern Greenland—and pulled up a fifteen-foot-long tube of dirt from the bottom. Then this frozen sediment was lost in a freezer for decades. It was accidentally rediscovered in 2017.
In 2019, University of Vermont scientist Andrew Christ looked at it through his microscope—and couldn't believe what he was seeing: twigs and leaves instead of just sand and rock. That suggested that the ice was gone in the recent geologic past—and that a vegetated landscape, perhaps a boreal forest, stood where a mile-deep ice sheet as big as Alaska stands today.
Over the last year, Christ and an international team of scientists—led by Paul Bierman at UVM, Joerg Schaefer at Columbia University and Dorthe Dahl-Jensen at the University of Copenhagen—have studied these one-of-a-kind fossil plants and sediment from the bottom of Greenland. Their results show that most, or all, of Greenland must have been ice-free within the last million years, perhaps even the last few hundred-thousand years.
Ice sheets typically pulverize and destroy everything in their path," says Christ, "but what we discovered was delicate plant structures—perfectly preserved. They're fossils, but they look like they died yesterday. It's atime capsuleof what used to live on Greenland that we wouldn't be able to find anywhere else."
The discovery helps confirm a new and troubling understanding that the Greenland ice has melted off entirely during recent warm periods in Earth's history—periods like the one we are now creating with human-caused climate change.
Understanding the Greenland Ice Sheet in the past is critical for predicting how it will respond to climate warming in the future and how quickly it will melt.
Andrew J. Christ el al., "A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2021442118
Study finds cancer cells may evade chemotherapy by going dormant
Cancer cells can dodge chemotherapy by entering a state that bears similarity to certain kinds of senescence, a type of "active hibernation" that enables them to weather the stress induced by aggressive treatments aimed at destroying them, according to a new study by scientists.
These findings have implications for developing new drug combinations that could block senescence and make chemotherapy more effective.
The investigators reported that this biologic process could help explain why cancers so often recur after treatment. The research was done in both organoids and mouse models made from patients' samples of acute myeloid leukemia (AML) tumors. The findings were also verified by looking at samples from AML patients that were collected throughout the course of treatment and relapse.
Acute myeloid leukemia can be put into remission with chemotherapy, but it almost always comes back, and when it does it's incurable.
For years, cancer researchers have studied how tumors are able to rebound after they appear to be completely wiped out by chemotherapy. One theory has been that because not all cells within a tumor are the same at the genetic level—a condition called tumor heterogeneity—a small subset of cells are able to resist treatment and begin growing again. Another theory involves the idea of tumor stem cells—that some of the cells within a tumor have special properties that allow them to re-form a tumor after chemotherapy has been given. The idea that senescence is involved does not replace these other theories. In fact, it could provide new insight into explaining these other processes.
In the study, the researchers found that when AML cells were exposed to chemotherapy, a subset of the cells went into a state of hibernation, or senescence, while at the same time assuming a condition that looked very much like inflammation. They looked similar to cells that have undergone an injury and need to promote wound healing—shutting down the majority of their functions while recruiting immune cells to nurse them back to health.
"These characteristics are also commonly seen in developing embryos that temporarily shut down their growth due to lack of nutrition, a state called embryonic diapause. Further research revealed that this inflammatory senescent state was induced by a protein called ATR, suggesting that blocking ATR could be a way to prevent cancer cells from adopting this condition. The investigators tested this hypothesis in the lab and confirmed that giving leukemia cells an ATR inhibitor before chemotherapy prevented them from entering senescence, thereby allowing chemotherapy to kill all of the cells.
Importantly, studies published at the same time from two other groups reported that the role of senescence is important not just for AML, but for recurrent cases of breast cancer, prostate cancer and gastrointestinal cancers as well.
Cihangir Duy et al. Chemotherapy induces senescence-like resilient cells capable of initiating AML recurrence, Cancer Discovery (2021). DOI: 10.1158/2159-8290.CD-20-1375
Practical nanozymes discovered to fight antimicrobial resistance
Nanozymes, a group of inorganic catalysis-efficient particles, have been proposed as promising antimicrobials against bacteria. They are efficient in killing bacteria, thanks to their production of reactive oxygen species (ROS).
Despite this advantage, nanozymes are generally toxic to bothbacteriaandmammalian cells, that is, they are also toxic to our owncells. This is mainly because of the intrinsic inability of ROS to distinguish bacteria from mammalian cells.
In a study published inNature Communications, the research team proposed a novel method to construct efficient-while-little-toxic nanozymes.
The researchers showed that nanozymes that generate surface-bound ROS selectively kill bacteria, while leaving the mammalian cells safe.
The selectivity is attributed to, on the one hand, the surface-bound nature of ROS generated by the nanozymes prepared by the team, and on the other hand, an unexpected antidote role of endocytosis, a cellular process that is common for mammalian cells while absent in bacteria.
Feng Gao et al. Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action, Nature Communications (2021). DOI: 10.1038/s41467-021-20965-3
Encrypting data in a way that ensures secure communication is an ever-growing challenge because crucial components of today's encryption systems cannot withstand future quantum computers. Researchers around the world are therefore working on technologies for novel encryption methods that are also based on quantum effects. The phenomenon of so-called quantum entanglement plays a particularly important role here. This means that in a quantum network, the stationary qubits of the network are entangled with the communication channel, which usually consists of photons (light particles). For the first time, physicists at the University of Bonn have now been able to demonstrate quantum entanglement between a stationary qubit, i.e. a two-state quantum system, and a photon with direct coupling to an optical fiber. The study has been published in the journal npj Quantum Information.
Pascal Kobel et al. Deterministic spin-photon entanglement from a trapped ion in a fiber Fabry–Perot cavity, npj Quantum Information (2021). DOI: 10.1038/s41534-020-00338-2
Quantum systems originate from the world of particles and smallest structures and may be relevant for future technologies. If different quantum information carriers (quantum nodes) are interconnected by quantum channels, researchers speak of quantum networks.
Scientists Reveal How Many Interstellar Objects May Be Visiting Our Solar System
According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly seven ISOs enter our Solar System every year and follow predictable orbits while they are here.
This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.
Outbreak of Mysterious Paralyzing Condition Squashed by COVID–19 Pandemic
The grim pall of theCOVID-19pandemicensures that 2020 will go down as an infamous year in the history of human disease.
But this dark chapter held some surprises we can be thankful for, too. In anew study, researchers found that a predicted 2020 outbreak of a mysterious paralyzing illness failed to materialize on schedule – and in a weird way, we actually have thecoronavirusto thank for it.
The condition in question is calledacute flaccid myelitis(AFM). This polio-like neurological disease mainly affects children, causing muscle weakness and, in some cases, permanent paralysis and even death.
Abody of previous researchhas linked AFM to a rareviruscalledenterovirus D68(EV-D68), and while it's not yet known how the virus manifests the symptoms of the AFM disease, coinciding outbreaks of the pair have led researchers to think they are almost certainly related.
In the new research, a team led by first author and infectious disease modeler Sang Woo Park from Princeton University tracked patterns of cases of EV-D68 between 2014 and 2019, with the virus staging significant resurgences in even-numbered years – 2014, 2016, and 2018 – which are thought to be attributable to climate-based factors.
The data suggested 2020 was due for another hit.
"We predicted that a major EV-D68 outbreak, and hence an AFM outbreak, would have still been possible in 2020 under normal epidemiological conditions,"the researchers explain in their study.
Of course, as the world was at pains to witness, the epidemiological conditions of 2020 were anything but ordinary, and the expected combo hit of EV-D68 and AFM never came.
India third-most polluted country; Delhi most polluted capital city: Report
India is the third-most polluted country in the world. Delhi is the most polluted capital city in the world. Thirty-seven of the forty most polluted cities in the world are in South Asia.
These are the findings of the 2020 World Air Quality Report released by IQAir.
A mere 1.6% of the cities in South Asia met the WHO PM2.5 target in 2020.
Thirty-seven of the forty most polluted cities in the world in 2020 are in South Asia.
Nearly 13 to 22% of deaths in South Asia are linked to air pollution.
Air pollution causes a loss of 7.4% of South Asia's GDP.
India, Pakistan, and Bangladesh generally experience the worst air quality in this region, with 32%, 67%, and 80% of cities averaging a US AQI measurement of “Unhealthy” (> 55.5 μg/m³), respectively.
India showed an overall improvement in several cities, with 63% reporting direct improvements over 2019 averages. All cities whose pollution levels increased in 2020 still show an overall downward trend from 2018 and earlier.
South and East Asian countries continue to be the most polluted locations.
Bangladesh, China, India, and Pakistan share 49 of the 50 of the most polluted cities worldwide.
Air pollution contributes to nearly 7 million premature deaths annually. A staggering 600,000 of these deaths include children.
Air pollution is estimated to cost the global economy upwards of $2.9 trillion per year, which is equal to 3.3% of the global GDP.
The Covid-19-induced lockdown resulted in a temporary reduction in fossil-fuel consumption. This resulted in a significant decrease in air pollution.
2020 saw a remarkable 65% of global cities experience air quality improvements from 2019, while 84% of countries saw improvements overall.
The report was compiled by the world's largest database of ground-based air pollution measurements, aggregating PM2.5 data published in real-time from ground-based sensors throughout 2020.
The 2020 World Air Quality Report includes data for 106 countries, up from 98 countries in 2019 and 69 countries in 2018.
This report highlights that urgent action is both possible and necessary to combat air pollution, which remains the world’s greatest environmental health threat.
Researchers identify a class of neurons that are most active during non-REM sleep
Typically, pyramidal cells and GABAergic interneurons in the brain are activated simultaneously. A team of neuroscientists at New York University, however, recently identified a unique class of neurons that do not fire at the same time as all principal neurons, cells and interneurons. Interestingly, the team found that these specific neurons are most active during the DOWN state of non-REM (NREM) sleep, when all other neuron types are silent.
In their study, researchers identified a class of neurons that appear to be most active when all other neurons (i.e., excitatory pyramidal and inhibitory neurons) are silent, in the DOWN state, during NREM stages of sleep. In their follow up experiments, they showed that these neurons are neuroglia-form cells found in the deeper layers of the neocortex, which specifically express genes known as ID2 and Nkx2.1.
When they examined this class of neurons more in depth, they observed that they had an entirely antagonistic relationship with all other known types of neurons in all wakefulness states (i.e., both when mammals are awake and asleep). This suggests that these neurons could have a unique function that sets them apart from all other cells in the brain.
Sleep down state-active ID2/Nkx2.1 interneurons in the neocortex. Nature Neuroscience(2021). DOI: 10.1038/s41593-021-00797-6.
Lightning strikes played a vital role in life's origins on Earth: study
Lightning strikes were just as important as meteorites in creating the perfect conditions for life to emerge on Earth, geologists say.
Minerals delivered to Earth in meteorites more than 4 billion years ago have long been advocated as key ingredients for the development of life on our planet.
Scientists thought minimal amounts of these minerals were also brought to early Earth through billions of lightning strikes.
But now researchers have established that lightning strikes were just as significant as meteorites in performing this essential function and allowing life to manifest.
They say this shows that life could develop on Earth-like planets through the same mechanism at any time if atmospheric conditions are right.
Scientists create model of an early human embryo from skin cells
In a discovery that will revolutionize research into the causes of early miscarriage, infertility and the study of early human development—an international team of scientists led by Monash University in Melbourne, Australia has generated a model of a human embryo from skin cells.
The team, led by Professor Jose Polo, has successfully reprogrammed these fibroblasts or skin cells into a 3-dimensional cellular structure that is morphologically and molecularly similar to human blastocysts. Called iBlastoids, these can be used to model the biology of early human embryos in the laboratory.
The achievement is a significant breakthrough for the future study of early human development and infertility. To date, the only way to study these first days has been through the use of difficult to obtain, and scarce, blastocysts obtained from IVF procedures.
As endangered birds lose their songs, they can't find mates
Male songbirds usually learn their tunes from adult mentors. But when aspiring crooners lack proper role models, they hit all the wrong notes—and have less success attracting mates.
For five years, ecologist Ross Crates has tracked the singing ability and breeding success ofcritically endangeredregent honeyeaters. Thesedistinctiveblack and yellow birds were once common across Australia, but habitat loss since the 1950s has shrunk their population to only about 300 or 400 wild birds today.
While male birds once formed large winter flocks, now they are sparsely distributed across the landscape, so many fly solo. That means fewer honeyeater mentors are nearby during young birds' impressionable first year.
Song learning in many birds is a process similar to humans learning languages—they learn by listening to other individuals. If you can't listen to other individuals, you don't know what you should be learning.
The researchers found that a significant portion of male birds appear to be learning tunes exclusively from other species they encounter. About 12% of male regent honeyeaters wind up producing mangled versions of songs typically sung by noisy friarbirds and black-faced cuckooshrikes, among other species.
In some species, such as mockingbirds, song mimicry adds flourish to love songs. But the female regent honeyeaters aren't impressed.
Unconventional male singers were less successful in wooing mates, the scientists found in researchpublishedTuesday in the journalProceedings of the Royal Society B. "We think the females are avoiding breeding and nesting with males that sing unusual songs.
For a population already on the brink of extinction, that's worrisome.
"This research suggests that the loss of a song language once the population reaches a very small size could accelerate their decline
It could be that female honeyeaters aren't even recognizing these unconventional singers as potential partners, and so they're not approaching them. Or it could be that they approach, "but then things go wrong if the males get courtship signals wrong."
Study finds evidence of 55 new chemicals in people
Scientists at UC San Francisco have detected 109 chemicals in a study of pregnant women, including 55 chemicals never before reported in people and 42 "mystery chemicals," whose sources and uses are unknown.
The chemicals most likely come from consumer products or other industrial sources. They were found both in the blood of pregnant women, as well as their newborn children, suggesting they are traveling through the mother's placenta.
The study will be published March 17, 2021, inEnvironmental Science & Technology.
These chemicals have probably been in people for quite some time, but our technology is now helping us to identify more of them
The scientific team used high-resolution mass spectrometry (HRMS) to identify man-made chemicals in people.
But, while these chemicals can be tentatively identified usingchemical libraries, they need to be confirmed by comparing them to the pure chemicals produced by manufacturers that are known as "analytical standards." And manufacturers do not always make these available.
The researchers report that 55 of the 109 chemicals they tentatively identified appear not to have been previously reported in people:
1 is used as a pesticide (bis(2,2,6,6-tetramethylpiperidini-4-y) decanedioate)
2 are PFASs (methyl perfluoroundecanoate, most likely used in the manufacturing of non-stick cookware and waterproof fabrics; 2-perfluorodecyl ethanoic acid)
10 are used as plasticizers (e.g. Sumilizer GA 80—used in food packaging, paper plates, small appliances)
2 are used in cosmetics
4 are high production volume (HPV) chemicals
37 have little to no information about their sources or uses (e.g., 1-(1-Acetyl-2,2,6,6-tetramethylpiperidin-4-yl)-3-dodecylpyrrolidine-2,5-dione, used in manufacturing fragrances and paints—this chemical is so little known that there is currently no acronym—and (2R0-7-hydroxy-8-(2-hydroxyethyl)-5-methoxy-2-,3-dihydrochromen-4-one (Acronym: LL-D-253alpha), for which there is limited to no information about its uses or sources
Nanobots are machines whose components are at the nano-scale (one-millionth of a millimeter), and can be designed in such a way that they have the ability to move autonomously in fluids. Although they are still in the research and development phase, significant advances are being made toward the use of nanorobots in biomedicine. Their applications are varied, from the identification of tumor cells to the release of drugs in specific locations of the body. Nanorobots powered by catalytic enzymes are among the most promising systems because they are fully biocompatible and can make use of "fuels" already available in the body for their propulsion. However, understanding the collective behavior of these nanorobots is essential to advance towards their use in clinical practice.
An ITMO Ph.D. student with her colleagues from Russia, Spain and Singapore has developed flexible sensing films based on silver nanoparticles that can be used to identify the presence of pesticide residue on the surface of agricultural produce in minutes. The research results were published in Nanoscale.
When religious leaders stand in a Q for the vaccine!
The world’s largest vaccine maker, Serum Institute of India, is testing a new virus-like particle vaccine for COVID-19 made with technology licensed from the UK-based SpyBiotech.Credit: Reuters/Amit Dave
Why does DNA spontaneously mutate? Quantum physics might explain.
Quantum mechanics, which rules the world of the teensy-tiny, may help explain why genetic mutations spontaneously crop up in DNA as it makes copies of itself, a recent study suggests.
Quantum mechanics describes the strange rules that governatomsand their subatomic components. When the rules of classicalphysics, which describe the big world, break down, quantum comes in to explain. In the case of DNA, classical physics offers one explanation for why changes can suddenly appear in a single rung of the spiraling ladder of DNA, resulting in what's called apoint mutation.
In a recent study, published Jan. 29 in the journalPhysical Chemistry Chemical Physics, researchers explore another explanation, showing that a quantum phenomenon called proton tunneling can cause point mutations by allowing positively charged protons inDNAto leap from place-to-place. This, in turn, can subtly change thehydrogenbridges that bind the two sides of DNA's double helix, which can lead to errors when it's time for DNA to make copies of itself.
In particular, this subtle change can potentially cause misprints in the DNA sequence, where the wrong "letters" get paired together as the strand replicates, the study authors note. These letters, known as bases, usually pair up in a certain way: A to T and G to C. But proton tunneling could cause some bases to mix-and-match.
Neuroscientists identify brain circuit motifs that support short-term memory
Humans have the innate ability to store important information in their mind for short periods of time, a capability known as short-term memory. Over the past few decades, numerous neuroscientists have tried to understand how neural circuits store short-term memories, as this could lead to approaches to assist individuals whose memory is failing and help to devise memory enhancing interventions.
Researchers have recently identified neural circuit motifs involved in how humans store short-term memories. Their findings, published in Nature Neuroscience, suggest that memory-related neural circuits contain recurrently connected modules that independently maintain selective and continuous activity.
Short-term memories are of approximately 10 seconds or so, for example, if you needed to remember a phone number while you looked for a pen to write the number. Individual neurons, however, are very forgetful, as they can only remember their inputs for about 10 milliseconds. It has been hypothesized that if two forgetful neurons were connected to each other, they could continuously remind each other of what they were supposed to remember so that the circuit can now hold information for many seconds.
It was found that neurons tended to be connected in clusters. This means that the circuit was composed of many independent clusters, or modules, that were each able to store short-term memories independently.
Much of the carbon in space is believed to exist in the form of large molecules called polycyclic aromatic hydrocarbons (PAHs). Since the 1980s, circumstantial evidence has indicated that these molecules are abundant in space, but they have not been directly observed.
Now, a team of researchers has identified two distinctive PAHs in a patch of space called the Taurus Molecular Cloud (TMC-1). PAHs were thought to form efficiently only at high temperatures—on Earth, they occur as byproducts of burning fossil fuels, and they're also found in char marks on grilled food. But the interstellar cloud where the research team observed them has not yet started forming stars, and the temperature is about 10 degrees above absolute zero.
This discovery suggests that these molecules can form at much lower temperatures than expected, and it may lead scientists to rethink their assumptions about the role of PAH chemistry in the formation of stars and planets, the researchers say.
Brett A. McGuire et al. Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH2CN) in TMC-1,The Astrophysical Journal(2020).iopscience.iop.org/article/10. … 847/2041-8213/aba632
Andrew M. Burkhardt et al. Ubiquitous aromatic carbon chemistry at the earliest stages of star formation,Nature Astronomy(2021). DOI: 10.1038/s41550-020-01253-4
Enigmatic circling behavior captured in whales, sharks, penguins, and sea turtles
Technological advances have made it possible for researchers to track the movements of large ocean-dwelling animals in three dimensions with remarkable precision in both time and space. Researchers reporting in the journal iScience on March 18 have now used this biologging technology to find that, for reasons the researchers don't yet understand, green sea turtles, sharks, penguins, and marine mammals all do something rather unusual: swimming in circles.
A wide variety of marine megafauna showed similar circling behavior, in which animals circled consecutively at a relatively constant speed more than twice.
This finding is surprising in part because swimming in a straight line is the most efficient way to move about.
Researchers report that some circling events were recorded at animals' foraging areas, suggesting that it might have some benefit for finding food.
It's possible the circling helps the animals to detect the magnetic field to navigate; interestingly, the researchers say, submarines also circle during geomagnetic observations. But it's also possible that the circling serves more than one purpose.
Artificial intelligence system detects errors when medication is self-administered
From swallowing pills to injecting insulin, patients frequently administer their own medication. But they don't always get it right. Improper adherence to doctors' orders is commonplace, accounting for thousands of deaths and billions of dollars in medical costs annually. Researchers now have developed a system to reduce those numbers for some types of medications.
The new technology pairs wireless sensing with artificial intelligence to determine when a patient is using an insulin pen or inhaler, and flags potential errors in the patient's administration method.
Assessment of medication self-administration using artificial intelligence, Nature Medicine (2021). DOI: 10.1038/s41591-021-01273-1
Bacteria Behind UTIs Make Their Own DNA Building Blocks From Your Urine
Some infectious bacteria have adapted so well to the human bladder, they appear to make their own DNA using chemicals in our urine.
The urinary tract is ahard placefor most bacteria to survive. That's why urine is often said to be sterile, although that'snot actually true.
Just like your gut, human urine is home to a community of microbes, known as a microbiota, and while most bacteria that live within it are harmless, sometimes a particular species can tip the scales, causing painful urinary tract infections (UTIs).
Streptococcus agalactiae is a known source of UTIs in some humans, and new research has now revealed how it can survive in such an unfriendly environment.
In a healthy human body, urine should be relatively low in the four nucleobases making up DNA's code, which are broken down into nitrogenous compounds and excreted out.
Sequencing theS. agalactiaegenome, scientists have now found a key, specialized gene, which allows the bacterium to exploit the presence of other compounds in our urine to produce at least one of these bases - guanine - in order for it to survive.
Similar genes havealso recently been foundinEscherichia coli(E. coli), which is the most common offender of human UTIs.
Usually, in the gut or the blood,E. coliandStreptococcusscavenge for certain chemicals they need to make DNA, borrowing products like guanine from our own bodies. In the urinary tract, however, these essential building blocks are ultimately broken down into uric acid, which means they are not as easy to find.
It's a tough situation, and it means bothE. coliandStreptococcusmust synthesize their own chemical bases if they want to grow and reproduce.
"It's basically a survival strategy to colonize the urine, an environment that not many organisms can live in
It seems to be a common strategy among species of bacteria that make up the microbiome of the urine."
In the study, scientists used mice to show how essential this specialized gene, known as guaA, truly is. CollectingStreptococcusstrains from several individuals, researchers compared a normalS. agalactiaeinfection with a form of the bacterium deficient in guaA.
Microbes that were unable to create their own guanine were unable to colonize the bladder of mice to the same extent. The same thing was found when researchers used synthetic human urine.
This suggests guaA is essential for aStreptococcusinfection to take hold in the bladder, not just in mice but also in us.
Arianna Eisenberg, 34, said she experienced muscle pains, insomnia, fatigue, and brain fog for eight months after getting sick. These symptoms are typical of what has become known as "long COVID".
But 36 hours after receiving a second dose of COVID-19 vaccine, her symptoms were gone, thePostreported.
Eisenberg's story is one of several describing a similar effect.
Daniel Griffith, an infectious diseases clinician and researcher at Columbia University, told The Verge on March 2 that around a third of his long COVID patients reported that they were feeling better after the vaccine.
In a YouTube video, Gez Medinger, a science journalist who reports on long COVID, did a survey of 473 long haulers among support groups on Facebook, The Verge reported, around a third of whom saw their symptoms improve after vaccination.
One small study from the UK's University of Bristol, which has not been peer reviewed, looked at giving vaccines to people with long COVID-19 symptoms, per theWashington Postreport.
The scientists gave the vaccine to 44 COVID long-haulers, and compared their reaction to a group of long-haulers who didn't get the vaccine.
They reported that those who had received the vaccine had a "small overall improvement in long COVID symptoms".
Chemists gain new insights into the behavior of water in an influenza virus channel
In a new study of water dynamics, a team of MIT chemists led by Professor Mei Hong, in collaboration with Associate Professor Adam Willard, has discovered that water in an ion channel is anisotropic, or partially aligned. The researchers' data, the first of their kind, prove the relation of water dynamics and order to the conduction of protons in an ion channel. The work also provides potential new avenues for the development of antiviral drugs or other treatments.
Members of the Hong lab conducted sophisticated nuclear magnetic resonance (NMR) experiments to prove the existence of anisotropic water in the proton channel of the influenza M virus, while members of the Willard group carried out independent all-atom molecular dynamics simulations to validate and augment the experimental data. Their study, of which Hong was the senior author, was published in Communications Biology
The influenza B virus protein BM2 is a protein channel that acidifies the virus, helping it to release its genetic material into infected cells. The water in this channel plays a critical role in helping the influenza virus become infectious, because it facilitates proton conduction inside the channel to cross the lipid membrane.
This new study has provided the missing link in a full understanding of the mixed hydrogen-bonded chain between water and histidine inside the M2 channel. To curb the flu virus protein, the channel would have to be plugged with small molecules—i.e., antiviral drugs—so that the water pathway would be broken.
the researchers were able to observe that the water network has fewer hydrogen-bonding bottlenecks in the open state than in the closed state. Thus, faster dynamics and higher orientational order of water molecules in the open channel establish the water network structure that is necessary for proton hopping and successful infection on the virus' part.
When a flu virus enters a cell, it goes into a small compartment called the endosome. The endosome compartment is acidic, which triggers the protein to open its water-permeated pathway and conduct the protons into the virus. Acidic pH has a high concentration of hydrogen ions, which is what the M2 protein conducts. Without the water molecules relaying the protons, the protons will not reach the histidine, a critical amino acid residue. The histidine is the proton-selective residue, and it rotates in order to shuttle the protons carried by the water molecules. The relay chain between the water moleculesand the histidine is therefore responsible for proton conduction through the M2 channel. Therefore, the findings indicated in this research could prove relevant to the development of antiviral drugs and other practical applications.
Martin D. Gelenter et al. Water orientation and dynamics in the closed and open influenza B virus M2 proton channels, Communications Biology (2021). DOI: 10.1038/s42003-021-01847-2
Bioengineers learn the secrets to precisely turning on and off genes
In a recent study , scientists have shown how to simultaneously harness multiple forms of regulation in living cells to strictly control gene expression and open new avenues for improved biotechnologies.
Engineered microbes are increasingly being used to enable the sustainable and clean production of chemicals, medicines and much more. To make this possible, bioengineers must control when specific sets of genes are turned on and off to allow for careful regulation of the biochemical processes involved.
Although turning on or off a gene sounds simple, getting a living cellto do it on command is a real challenge. Every cell is slightly different, and the processes involved are not 100 percent reliable. To solve this issue, the team took inspiration from nature where key events are often controlled by multiple processes simultaneously.
The team showed that by using this type of multi-level regulation, they could create some of the most high-performance switches for gene expression built to date. They demonstrated that even when used outside of living cells, these multi-level systems offered some of the most stringent control over gene expression yet seen.
Harnessing the central dogma for stringent multi-level control of gene expression, Nature Communications (2021).
Researchers find evidence of elusive Odderon particle
For 50 years, the research community has been hunting unsuccessfully for the so-called Odderon particle. Now, a Swedish-Hungarian research group has discovered the mythical particle with the help of extensive analysis of experimental data from the Large Hadron Collider at CERN in Switzerland.
In 1973, two French particle physicists found that, according to their calculations, there was a previously unknown quasi-particle. The discovery sparked an international hunt.
The Odderon particle is what briefly forms whenprotonscollide in high-energy collisions, and in some cases do not shatter, but bounce off one another and scatter. Protons are made up of quarks and gluons, that briefly form Odderon and Pomeron particles.
And now a research team, involving researchers from Lund University, has succeeded in identifying the Odderon in connection with an advanced data analysis study at the particle accelerator CERN.
T. Csörgő et al. Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies, The European Physical Journal C (2021). DOI: 10.1140/epjc/s10052-021-08867-6
Surviving Covid-19 protects most people against reinfection for at least six months, but elderly patients are more likely to be laid low by the virus a second time, researchers reported Thursday. An assessment of reinfection rates in Denmark last year showed that just over half a percent of people who tested positive for Covid during the first wave from March to May did so again during the second wave, from September to December. Among these, the researchers found that initial infection with Covid-19 was likely to bestow 80 percent protection from reinfection among under-65s, but that dropped to just 47 percent in older people. "We did not identify anything to indicate that protection against reinfection declines within six months of having Covid-19, say the researchers.
The researchers said this meant that initial infection with Covid-19 was likely to bestow 80 percent protection from reinfection among under 65s.
For those aged over 65, however, the protection level diminished sharply.
Of the more than 1,900 over-65s who tested positive during the first wave, 17 (0.88 percent) tested positive again during the second.
This compared to 1,866 out of more than 90,000 over-65s (two percent) who tested positive during the second wave but not the first -- a protection difference of 47 percent.
The study confirms what a number of others appeared to suggest: reinfection with Covid-19 is rare in younger, healthy people.
Dr. Krishna Kumari Challa
Part 2 - extreme hot planets
In our study, we used publicly available data, taken by the Hubble Space Telescope, to obtain the eclipse spectrum of this planet.
We then used open-source software to extract the presence of molecules and found there were plenty of metals (made from molecules). This discovery is interesting as it was previously thought that these molecules would not be present at such extreme temperatures – they would be broken apart into smaller compounds.
Subject to the strong gravitational pull from its host star, Kelt-9 b is “tidally locked”, which means that the same face of the planet permanently faces the star. This results in a strong temperature difference between the planet’s day and night sides. As the eclipse observations probe the hotter day-side, we suggested that the observed molecules could in fact be dragged by dynamic processes from the cooler regions, such as the night-side or from deeper in the interior of the planet. These observations suggest that the atmospheres of these extreme worlds are ruled by complex processes that are poorly understood.
Kelt-9 b is interesting because of its inclined orbit of about 80 degrees. This suggests a violent past, with possible collisions, which in fact is also seen for many other planets of this class. It is most likely that this planet formed away from its parent star and that the collisions happened as it migrated inwards toward the star. This supports the theory that large planets tend to form away from their host star in proto-stellar disks – which give rise to solar systems – capturing gaseous and solid materials as they migrate toward their star.
https://theconversation.com/how-can-some-planets-be-hotter-than-sta...
Mar 12, 2021
Dr. Krishna Kumari Challa
Physicists measure smallest gravitational field yet
Physicists in Austria have measured the gravitational field from the smallest ever object: a gold sphere with a diameter of just 2 mm. Carried out using a miniature torsion balance, the measurement paves the way to even more sensitive gravitational probes that could reveal gravity’s quantum nature.
The latest work, in contrast, uses a gold sphere with a mass of just 92 mg as its source. Markus Aspelmeyer and Tobias Westphal of the Institute for Quantum Optics and Quantum Information in Vienna and colleagues positioned this mass a few millimetres away from another tiny gold sphere with about the same mass located at one end of a 4 cm-long glass rod. The rod was suspended at its centre via a silica fibre, while a third sphere at the far end of the rod acted as a counterbalance.
Such “torsion balances” have been used for more than 200 years to make precise measurements of gravity. The idea is that the source mass pulls the near end of the bar towards itself, causing the suspending fibre or wire to rotate. By measuring this rotation and balancing it against the stiffness of the wire, the strength of the gravitational interaction can be calculated. The fact that the bar moves horizontally means it is less exposed to the far larger gravitational field of the Earth.
A major challenge with such experiments is screening out noise. Aspelmeyer and colleagues did this by placing the balance in a vacuum to limit acoustic and thermal interference, while also grounding the source mass and placing a Faraday shield between it and the test mass to reduce electromagnetic interactions. In addition, they mainly collected data at night to minimize ambient sources of gravity. This is important because the gravitational attraction of the source mass is equivalent to the pull of a person standing 2.5 m from the experiment or a Vienna tram 50 m away.
To generate signals above the remaining noise, the researchers used a bending piezoelectric device to cyclically move the source towards and away from the test mass. Doing this at a fixed frequency (12.7 mHz) allowed them to look for a corresponding variation in the rotation of the balance – which they measured by bouncing a laser beam off a mirror below the silica fibre.
After repeating this process hundreds of times over a 13.5-hour period and then converting the time-series data into a frequency spectrum, Aspelmeyer and colleagues identified two clear signals above the background. These were the principle oscillation at 12.7 mHz and, at 25.4 mHz, the second harmonic generated by the gravitational field’s nonlinear variation in space. As the researchers point out, both harmonics were well above the resonant frequency of the oscillating balance and below the frequencies of readout noise.
https://www.nature.com/articles/s41586-021-03250-7.epdf?sharing_tok...
https://physicsworld.com/a/physicists-measure-smallest-gravitationa...
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Mar 12, 2021
Dr. Krishna Kumari Challa
Antarctic detector spots cosmic antineutrino
A huge neutrino detector in the Antarctic ice sheet might have seen the first evidence of a rare neutrino-interaction process called the Glashow resonance.
The IceCube Neutrino Observatory, buried in the deep ice near the Amundsen–Scott South Pole Station, observes eye-wateringly powerful neutrinos produced by sources such as active galactic nuclei and supernovae. The observatory detected a shower of secondary particles that look likely to have been caused by a collision between an electron antineutrino travelling close to th.... If confirmed by more observations, the finding provides further confirmation of the standard model of particle physics, proves the existence of cosmic antineutrinos and opens the door to a better understanding of the wild stuff going on in the cosmos.
https://www.nature.com/articles/d41586-021-00486-1?utm_source=Natur...
Mar 12, 2021
Dr. Krishna Kumari Challa
Membrane around tumors may be key to preventing metastasis
For cancer cells to metastasize, they must first break free of a tumors own defenses. Most tumors are sheathed in a protective basement membrane a thin, pliable film that holds cancer cells in place as they grow and divide. Before spreading to other parts of the body, the cells must breach the basement membrane, a material that itself has been tricky for scientists to characterize. Now MIT engineers have probed the basement membrane of breast cancer tumors and found that the seemingly delicate coating is as tough as plastic wrap, yet surprisingly elastic like a party balloon, able to inflate to twice its original size. But while a balloon becomes much easier to blow up after some initial effort, the team found that a basement membrane becomes stiffer as it expands. This stiff yet elastic quality may help basement membranes control how tumors grow.
The fact that the membranes appear to stiffen as they expand suggests that they may restrain a tumor’s growth and potential to spread, or metastasize, at least to a certain extent.
The findings, published this week in the Proceedings of the National Academy of Sciences, may open a new route toward preventing tumor metastasis, which is the most common cause of cancer-related deaths.
Now scientists can think of ways to add new materials or drugs to further enhance this stiffening effect, and increase the toughness of the membrane to prevent cancer cells from breaking through
https://news.mit.edu/2021/membrane-tumors-metastasis-0308
Mar 12, 2021
Dr. Krishna Kumari Challa
Sonolithography: In‐Air Ultrasonic Particulate and Droplet Patterning
Sonolithography is based on the application of acoustic radiation forces arising from the interference of ultrasonic standing waves to direct airborne particle/droplet accumulation. Sonolithography is capable of rapidly patterning micrometer to millimeter scale materials onto a wide variety of substrates over a macroscale (cm2) surface area and can be used for both indirect and direct cell patterning.
Mar 12, 2021
Dr. Krishna Kumari Challa
I ain't afraid of no ghosts: people with mind-blindness not so easily spooked
People with aphantasia – that is, the inability to visualise mental images – are harder to spook with scary stories, a new UNSW Sydney study shows.
The study, published today in Proceedings of the Royal Society B, tested how aphantasic people reacted to reading distressing scenarios, like being chased by a shark, falling off a cliff, or being in a plane that’s about to crash.
The researchers were able to physically measure each participant’s fear response by monitoring changing skin conductivity levels – in other words, how much the story made a person sweat. This type of test is commonly used in psychology research to measure the body’s physical expression of emotion.
According to the findings, scary stories lost their fear factor when the readers couldn’t visually imagine the scene – suggesting imagery may have a closer link to emotions than scientists previously thought.
Researchers found the strongest evidence yet that mental imagery plays a key role in linking thoughts and emotions.
Aphantasia affects 2-5 per cent of the population, but there is still very little known about the condition.
A UNSW study published last year found that aphantasia is linked to a widespread pattern of changes to other cognitive processes, like remembering, dreaming and imagining.
https://royalsocietypublishing.org/doi/10.1098/rspb.2021.0267
https://researchnews.cc/news/5578/I-ain-t-afraid-of-no-ghosts--peop...
Mar 12, 2021
Dr. Krishna Kumari Challa
Mar 12, 2021
Dr. Krishna Kumari Challa
Three Ways Quantum Physics Affects Your Daily Life
Quantum physics is all around us. The universe as we know it runs on quantum rules, and while the classical physics that emerges when you apply quantum physics to enormously huge numbers of particles seem very different, there are lots of familiar, everyday phenomena that owe their existence to quantum effects. Here are a few examples of things you probably run into in your everyday life without realizing that they're quantum:
Toasters: The red glow of a heating element as you toast a slice of bread or a bagel is a very familiar sight for most of us. It's also the place where quantum physics got its start: Explaining why hot objects glow that particular color of red is the problem that quantum physics was invented to solve.
"quantum hypothesis" (giving the eventual theory its name) that the light could only be emitted in discrete chunks of energy, integer multiples of a small constant times the frequency of the light. For high-frequency light, this energy quantum is larger than the share of heat energy allotted to that frequency, and thus no light is emitted at that frequency. This cuts off the high-frequency light, and leads to a formula that matches the observed spectrum of light from hot objects to great precision.
So, every time you toast bread, you're looking at the place where quantum physics got its start.
Fluorescent Lights: Old-school incandescent light bulbs make light by getting a piece of wire hot enough to emit a bright white glow, which makes them quantum in the same way that a toaster is. If you have fluorescent bulbs around-- either the long tubes or the newer twisty CFL bulbs, you're getting light from another revolutionary quantum process.
Computers: While Bohr's quantum model was undeniably useful, it didn't initially come with a physical reason as to why there should be special states for electrons within atoms. That didn't come for almost ten years, but once the idea got locked it, it turned out to be the basis for the most transformative technological revolution of the last century.
So, every time you turn on your computer (say, to read a blog post about quantum physics), you're exploiting the wave nature of electrons, and the unprecedented control of materials that allows. It may not be the sexy kind of quantum computer, but every modern computer needs quantum physics to work properly.
https://www.forbes.com/sites/chadorzel/2018/12/04/three-ways-quantu...
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Mar 13, 2021
Dr. Krishna Kumari Challa
Astronomers detect a black hole on the move
Scientists have long theorized that supermassive black holes can wander through space—but catching them in the act has proven difficult. Now, researchers at the Center for Astrophysics | Harvard & Smithsonian have identified the clearest case to date of a supermassive black hole in motion. Their results are published today in the Astrophysical Journal.
We don't expect the majority of supermassive black holes to be moving; they're usually content to just sit around. They're just so heavy that it's tough to get them going. Consider how much more difficult it is to kick a bowling ball into motion than it is to kick a soccer ball—realizing that in this case, the 'bowling ball' is several million times the mass of our Sun. That's going to require a pretty mighty kick.
Usually the velocities of the black holes the same as the velocities of the galaxies they reside in. We expect them to have the same velocity. If they don't, that implies the black hole has been disturbed.
For their search, the team initially surveyed 10 distant galaxies and the supermassive black holes at their cores. They specifically studied black holes that contained water within their accretion disks—the spiral structures that spin inward towards the black hole.
As the water orbits around the black hole, it produces a laser-like beam of radio light known as a maser. When studied with a combined network of radio antennas using a technique known as very long baseline interferometry (VLBI), masers can help measure a black hole's velocity very precisely.
The technique helped the team determine that nine of the 10 supermassive black holes were at rest—but one stood out and seemed to be in motion.
Located 230 million light-years away from Earth, the black hole sits at the center of a galaxy named J0437+2456. Its mass is about three million times that of our Sun.
Using follow-up observations with the Arecibo and Gemini Observatories, the team has now confirmed their initial findings. The supermassive black hole is moving with a speed of about 110,000 miles per hour inside the galaxy J0437+2456.
But what's causing the motion is not known. The team suspects there are two possibilities.
Mar 13, 2021
Dr. Krishna Kumari Challa
blackhole movement - 2
We may be observing the aftermath of two supermassive black holes merging. The result of such a merger can cause the newborn black hole to recoil, and we may be watching it in the act of recoiling or as it settles down again.
But there's another, perhaps even more exciting possibility: the black hole may be part of a binary system.
Further observations, however, will ultimately be needed to pin down the true cause of this supermassive black hole's unusual motion.
Dominic W. Pesce et al, A Restless Supermassive Black Hole in the Galaxy J0437+2456, The Astrophysical Journal (2021). DOI: 10.3847/1538-4357/abde3d
https://phys.org/news/2021-03-astronomers-black-hole.html?utm_sourc...
Mar 13, 2021
Dr. Krishna Kumari Challa
Accurate aging of wild animals thanks to first epigenetic clock for bats
A new study by researchers found that DNA from tissue samples can be used to accurately predict the age of bats in the wild. The study also showed age-related changes to the DNA of long-lived species are different from those in short-lived species, especially in regions of the genome near genes associated with cancer and immunity. This work provides new insight into causes of age-related declines.
This is the first research paper to show that animals in the wild can be accurately aged using an epigenetic clock, which predicts age based on specific changes to DNA. This work provides a new tool for biologists studying animals in the wild. In addition, the results provide insight into possible mechanisms behind the exceptional longevity of many bat species. The study appears in the March 12, 2021, issue of the journal Nature Communications.
The researchers looked at DNA from 712 bats of known age, representing 26 species, to find changes in DNA methylation at sites in the genome known to be associated with aging. DNA methylation is a process that switches genes off. It occurs throughout development and is an important regulator for cells. Overall, methylation tends to decrease throughout the genome with age. Using machine learning to find patterns in the data, the researchers found that they could estimate a bat's age to within a year based on changes in methylation at 160 sites in the genome. The data also revealed that very long-lived bat species exhibit less change in methylation overall as they age than shorter-lived bats.
https://www.sciencedaily.com/releases/2021/03/210312095814.htm#:~:t....
https://phys.org/news/2021-03-accurate-aging-wild-animals-epigeneti...
Mar 13, 2021
Dr. Krishna Kumari Challa
Bacterial communities vary on different parts of the eye surface
A pioneering study led by University of Saskatchewan (USask) veterinary ophthalmologist Dr. Marina Leis (DVM, DACVO) shows that bacterial communities vary on different parts of the eye surface—a finding that significantly alters understanding of the mechanisms of eye disease and can lead to developing new treatments.
Mar 13, 2021
Dr. Krishna Kumari Challa
Researchers identify off switch for alcoholism
A study led by the Monash Institute of Pharmaceutical Sciences and the Florey Institute of Neuroscience and Mental Health uncovered a potential therapeutic target to treat alcohol use disorder (AUD) by targeting a specific receptor in the brain. The researchers found that by targeting the muscarinic M4 receptor in the brain, both habitual drinking and the likelihood to relapse could be improved in those suffering from alcohol addiction.
The team performed genome-wide RNA sequencing and protein expression studies in human tissue samples from people with AUD and non-drinkers to identify potential therapeutic targets.
https://www.monash.edu/pharm/about/news/news-listing/2020/researche...
https://researchnews.cc/news/5598/Researchers-identify-off-switch-f...
Mar 13, 2021
Dr. Krishna Kumari Challa
Scientists Find a Natural Protein That Stops Allergies And Autoimmune Conditions
It's called neuritin.
Using transgenic mice and cultures of cells taken from human tonsils, researchers have now found evidence of how our bodies might defend against the mistakes that result in conditions such as asthma, food allergies, and lupus. They found a protein called neuritin, produced by immune cells. It acts a bit like an inbuilt, boss-level antihistamine.
Neuritin suppresses formation of rogue plasma cells which are the cells that produce harmful antibodies.
https://www.cell.com/cell/fulltext/S0092-8674(21)00177-X?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS009286742100177X%3Fshowall%3Dtrue
https://www.sciencealert.com/our-bodies-do-have-a-natural-answer-fo...
Mar 13, 2021
Dr. Krishna Kumari Challa
Faster-Than-Light Travel Is Possible Within Einstein's Physics, Astrophysicist Shows
Physicists are not the kind of people who give up easily, though. Give them an impossible dream, and they'll give you an incredible, hypothetical way of making it a reality. Maybe.
In a new study by physicist Erik Lentz from Göttingen University in Germany, we may have a viable solution to the dilemma, and it's one that could turn out to be more feasible than other would-be warp drives.
This is an area that attracts plenty of bright ideas, each offering a different approach to solving the puzzle of faster-than-light travel: achieving a means of sending something across space at superluminal speeds.
There are some problems with this notion, however. Within conventional physics, in accordance with Albert Einstein's theories of relativity, there's no real way to reach or exceed the speed of light, which is something we'd need for any journey measured in light-years.
That hasn't stopped physicists from trying to break this universal speed limit, though.
While pushing matter past the speed of light will always be a big no-no, spacetime itself has no such rule. In fact, the far reaches of the Universe are already stretching away faster than its light could ever hope to match.
To bend a small bubble of space in a similar fashion for transport purposes, we'd need to solve relativity's equations to create a density of energy that's lower than the emptiness of space. While this kind of negative energy happens on a quantum scale, piling up enough in the form of 'negative mass' is still a realm for exotic physics.
In addition to facilitating other kinds of abstract possibilities, such as wormholes and time travel, negative energy could help power what's known as the Alcubierre warp drive.
This speculative concept would make use of negative energy principles to warp space around a hypothetical spacecraft, enabling it to effectively travel faster than light without challenging traditional physical laws, except for the reasons explained above, we can't hope to provide such a fantastical fuel source to begin with.
https://www.sciencealert.com/faster-than-light-travel-is-possible-w...
Mar 13, 2021
Dr. Krishna Kumari Challa
Female scientists who changed the world – from discovering radioactivity to making Covid-19 vaccines
Mar 15, 2021
Dr. Krishna Kumari Challa
Skin-immersion study shows serious damage after 12 hours in water
A new study from Binghamton University researchers could change the way that medical professionals and scientists think about the long-term effects of skin immersion in water.
Researchers tested samples of stratum corneum (the outer layer of human skin) from subjects 27 to 87 years old.
After 12 hours of immersion, the skin loses plasticity because of reduced ability to hold water. It also depletes both lipids and natural moisturizing factors, which can lead to long-term problems.
Essity, a global hygiene and health firm based on Sweden, helped to fund the study and assisted in the research to better understand skin damage caused by diaper dermatitis, when infants or incontinent adults are not regularly changed.
the findings have implications in a variety of different fields, including cryo-preservation, organ transport for transplantation, divers’ health, forensics and various foot-immersion syndromes.
https://pdf.sciencedirectassets.com/271007/1-s2.0-S0022202X73X90005...
https://www.binghamton.edu/news/story/2913/skin-immersion-study-sho....
https://researchnews.cc/news/5641/Skin-immersion-study-shows-seriou...
Mar 15, 2021
Dr. Krishna Kumari Challa
Juno Discovers Mars’ Dust Storms Fill Solar System
Mar 15, 2021
Dr. Krishna Kumari Challa
Wearable microgrid runs on renewable energy from the body
Mar 15, 2021
Dr. Krishna Kumari Challa
Scientists discovered plants beneath mile-deep Greenland ice
In 1966, US Army scientists drilled down through nearly a mile of ice in northwestern Greenland—and pulled up a fifteen-foot-long tube of dirt from the bottom. Then this frozen sediment was lost in a freezer for decades. It was accidentally rediscovered in 2017.
In 2019, University of Vermont scientist Andrew Christ looked at it through his microscope—and couldn't believe what he was seeing: twigs and leaves instead of just sand and rock. That suggested that the ice was gone in the recent geologic past—and that a vegetated landscape, perhaps a boreal forest, stood where a mile-deep ice sheet as big as Alaska stands today.
Over the last year, Christ and an international team of scientists—led by Paul Bierman at UVM, Joerg Schaefer at Columbia University and Dorthe Dahl-Jensen at the University of Copenhagen—have studied these one-of-a-kind fossil plants and sediment from the bottom of Greenland. Their results show that most, or all, of Greenland must have been ice-free within the last million years, perhaps even the last few hundred-thousand years.
Ice sheets typically pulverize and destroy everything in their path," says Christ, "but what we discovered was delicate plant structures—perfectly preserved. They're fossils, but they look like they died yesterday. It's a time capsule of what used to live on Greenland that we wouldn't be able to find anywhere else."
The discovery helps confirm a new and troubling understanding that the Greenland ice has melted off entirely during recent warm periods in Earth's history—periods like the one we are now creating with human-caused climate change.
Understanding the Greenland Ice Sheet in the past is critical for predicting how it will respond to climate warming in the future and how quickly it will melt.
Andrew J. Christ el al., "A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2021442118
https://phys.org/news/2021-03-scientists-stunned-beneath-mile-deep-...
Mar 16, 2021
Dr. Krishna Kumari Challa
Study finds cancer cells may evade chemotherapy by going dormant
Cancer cells can dodge chemotherapy by entering a state that bears similarity to certain kinds of senescence, a type of "active hibernation" that enables them to weather the stress induced by aggressive treatments aimed at destroying them, according to a new study by scientists.
These findings have implications for developing new drug combinations that could block senescence and make chemotherapy more effective.
The investigators reported that this biologic process could help explain why cancers so often recur after treatment. The research was done in both organoids and mouse models made from patients' samples of acute myeloid leukemia (AML) tumors. The findings were also verified by looking at samples from AML patients that were collected throughout the course of treatment and relapse.
Acute myeloid leukemia can be put into remission with chemotherapy, but it almost always comes back, and when it does it's incurable.
For years, cancer researchers have studied how tumors are able to rebound after they appear to be completely wiped out by chemotherapy. One theory has been that because not all cells within a tumor are the same at the genetic level—a condition called tumor heterogeneity—a small subset of cells are able to resist treatment and begin growing again. Another theory involves the idea of tumor stem cells—that some of the cells within a tumor have special properties that allow them to re-form a tumor after chemotherapy has been given. The idea that senescence is involved does not replace these other theories. In fact, it could provide new insight into explaining these other processes.
In the study, the researchers found that when AML cells were exposed to chemotherapy, a subset of the cells went into a state of hibernation, or senescence, while at the same time assuming a condition that looked very much like inflammation. They looked similar to cells that have undergone an injury and need to promote wound healing—shutting down the majority of their functions while recruiting immune cells to nurse them back to health.
"These characteristics are also commonly seen in developing embryos that temporarily shut down their growth due to lack of nutrition, a state called embryonic diapause. Further research revealed that this inflammatory senescent state was induced by a protein called ATR, suggesting that blocking ATR could be a way to prevent cancer cells from adopting this condition. The investigators tested this hypothesis in the lab and confirmed that giving leukemia cells an ATR inhibitor before chemotherapy prevented them from entering senescence, thereby allowing chemotherapy to kill all of the cells.
Importantly, studies published at the same time from two other groups reported that the role of senescence is important not just for AML, but for recurrent cases of breast cancer, prostate cancer and gastrointestinal cancers as well.
Cihangir Duy et al. Chemotherapy induces senescence-like resilient cells capable of initiating AML recurrence, Cancer Discovery (2021). DOI: 10.1158/2159-8290.CD-20-1375
https://medicalxpress.com/news/2021-03-cancer-cells-evade-chemother...
Mar 16, 2021
Dr. Krishna Kumari Challa
Practical nanozymes discovered to fight antimicrobial resistance
Nanozymes, a group of inorganic catalysis-efficient particles, have been proposed as promising antimicrobials against bacteria. They are efficient in killing bacteria, thanks to their production of reactive oxygen species (ROS).
Despite this advantage, nanozymes are generally toxic to both bacteria and mammalian cells, that is, they are also toxic to our own cells. This is mainly because of the intrinsic inability of ROS to distinguish bacteria from mammalian cells.
In a study published in Nature Communications, the research team proposed a novel method to construct efficient-while-little-toxic nanozymes.
The researchers showed that nanozymes that generate surface-bound ROS selectively kill bacteria, while leaving the mammalian cells safe.
The selectivity is attributed to, on the one hand, the surface-bound nature of ROS generated by the nanozymes prepared by the team, and on the other hand, an unexpected antidote role of endocytosis, a cellular process that is common for mammalian cells while absent in bacteria.
Feng Gao et al. Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action, Nature Communications (2021). DOI: 10.1038/s41467-021-20965-3
https://phys.org/news/2021-03-nanozymes-antimicrobial-resistance.ht...
Mar 16, 2021
Dr. Krishna Kumari Challa
When memory qubits and photons get entangled
Encrypting data in a way that ensures secure communication is an ever-growing challenge because crucial components of today's encryption systems cannot withstand future quantum computers. Researchers around the world are therefore working on technologies for novel encryption methods that are also based on quantum effects. The phenomenon of so-called quantum entanglement plays a particularly important role here. This means that in a quantum network, the stationary qubits of the network are entangled with the communication channel, which usually consists of photons (light particles). For the first time, physicists at the University of Bonn have now been able to demonstrate quantum entanglement between a stationary qubit, i.e. a two-state quantum system, and a photon with direct coupling to an optical fiber. The study has been published in the journal npj Quantum Information.
Pascal Kobel et al. Deterministic spin-photon entanglement from a trapped ion in a fiber Fabry–Perot cavity, npj Quantum Information (2021). DOI: 10.1038/s41534-020-00338-2
Quantum systems originate from the world of particles and smallest structures and may be relevant for future technologies. If different quantum information carriers (quantum nodes) are interconnected by quantum channels, researchers speak of quantum networks.
https://phys.org/news/2021-03-memory-qubits-photons-entangled.html?...
Mar 16, 2021
Dr. Krishna Kumari Challa
The Mating Dance of a bird
Mar 16, 2021
Dr. Krishna Kumari Challa
Mar 16, 2021
Dr. Krishna Kumari Challa
Scientists Reveal How Many Interstellar Objects May Be Visiting Our Solar System
According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly seven ISOs enter our Solar System every year and follow predictable orbits while they are here.
This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.
https://www.universetoday.com/150478/there-should-be-about-7-inters...
Mar 16, 2021
Dr. Krishna Kumari Challa
Outbreak of Mysterious Paralyzing Condition Squashed by COVID–19 Pandemic
The grim pall of the COVID-19 pandemic ensures that 2020 will go down as an infamous year in the history of human disease.
But this dark chapter held some surprises we can be thankful for, too. In a new study, researchers found that a predicted 2020 outbreak of a mysterious paralyzing illness failed to materialize on schedule – and in a weird way, we actually have the coronavirus to thank for it.
The condition in question is called acute flaccid myelitis (AFM). This polio-like neurological disease mainly affects children, causing muscle weakness and, in some cases, permanent paralysis and even death.
For decades, cases of AFM were very rare, but in recent years, larger outbreaks across the US and elsewhere have occurred, seemingly reoccurring every two years.
A body of previous research has linked AFM to a rare virus called enterovirus D68 (EV-D68), and while it's not yet known how the virus manifests the symptoms of the AFM disease, coinciding outbreaks of the pair have led researchers to think they are almost certainly related.
In the new research, a team led by first author and infectious disease modeler Sang Woo Park from Princeton University tracked patterns of cases of EV-D68 between 2014 and 2019, with the virus staging significant resurgences in even-numbered years – 2014, 2016, and 2018 – which are thought to be attributable to climate-based factors.
The data suggested 2020 was due for another hit.
"We predicted that a major EV-D68 outbreak, and hence an AFM outbreak, would have still been possible in 2020 under normal epidemiological conditions," the researchers explain in their study.
Of course, as the world was at pains to witness, the epidemiological conditions of 2020 were anything but ordinary, and the expected combo hit of EV-D68 and AFM never came.
https://stm.sciencemag.org/content/13/584/eabd2400
https://www.sciencealert.com/outbreak-of-mysterious-paralyzing-cond...
Mar 16, 2021
Dr. Krishna Kumari Challa
https://www.iqair.com/world-most-polluted-cities
India third-most polluted country; Delhi most polluted capital city: Report
India is the third-most polluted country in the world. Delhi is the most polluted capital city in the world. Thirty-seven of the forty most polluted cities in the world are in South Asia.
These are the findings of the 2020 World Air Quality Report released by IQAir.
This report highlights that urgent action is both possible and necessary to combat air pollution, which remains the world’s greatest environmental health threat.
https://health.economictimes.indiatimes.com/news/industry/india-thi...
Mar 17, 2021
Dr. Krishna Kumari Challa
Mar 17, 2021
Dr. Krishna Kumari Challa
Researchers identify a class of neurons that are most active during non-REM sleep
Typically, pyramidal cells and GABAergic interneurons in the brain are activated simultaneously. A team of neuroscientists at New York University, however, recently identified a unique class of neurons that do not fire at the same time as all principal neurons, cells and interneurons. Interestingly, the team found that these specific neurons are most active during the DOWN state of non-REM (NREM) sleep, when all other neuron types are silent.
In their study, researchers identified a class of neurons that appear to be most active when all other neurons (i.e., excitatory pyramidal and inhibitory neurons) are silent, in the DOWN state, during NREM stages of sleep. In their follow up experiments, they showed that these neurons are neuroglia-form cells found in the deeper layers of the neocortex, which specifically express genes known as ID2 and Nkx2.1.
When they examined this class of neurons more in depth, they observed that they had an entirely antagonistic relationship with all other known types of neurons in all wakefulness states (i.e., both when mammals are awake and asleep). This suggests that these neurons could have a unique function that sets them apart from all other cells in the brain.
Sleep down state-active ID2/Nkx2.1 interneurons in the neocortex. Nature Neuroscience(2021). DOI: 10.1038/s41593-021-00797-6.
https://medicalxpress.com/news/2021-03-class-neurons-non-rem.html?u...
Mar 17, 2021
Dr. Krishna Kumari Challa
Lightning strikes played a vital role in life's origins on Earth: study
Lightning strikes were just as important as meteorites in creating the perfect conditions for life to emerge on Earth, geologists say.
Minerals delivered to Earth in meteorites more than 4 billion years ago have long been advocated as key ingredients for the development of life on our planet.
Scientists thought minimal amounts of these minerals were also brought to early Earth through billions of lightning strikes.
But now researchers have established that lightning strikes were just as significant as meteorites in performing this essential function and allowing life to manifest.
They say this shows that life could develop on Earth-like planets through the same mechanism at any time if atmospheric conditions are right.
Lightning strikes as a major facilitator of prebiotic phosphorus reduction on early Earth, Nature Communications (2021). DOI: 10.1038/s41467-021-21849-2 , dx.doi.org/10.1038/s41467-021-21849-2
https://phys.org/news/2021-03-life-earth-blue.html?utm_source=nwlet...
Mar 17, 2021
Dr. Krishna Kumari Challa
Scientists create model of an early human embryo from skin cells
In a discovery that will revolutionize research into the causes of early miscarriage, infertility and the study of early human development—an international team of scientists led by Monash University in Melbourne, Australia has generated a model of a human embryo from skin cells.
The team, led by Professor Jose Polo, has successfully reprogrammed these fibroblasts or skin cells into a 3-dimensional cellular structure that is morphologically and molecularly similar to human blastocysts. Called iBlastoids, these can be used to model the biology of early human embryos in the laboratory.
The achievement is a significant breakthrough for the future study of early human development and infertility. To date, the only way to study these first days has been through the use of difficult to obtain, and scarce, blastocysts obtained from IVF procedures.
Modelling human blastocysts by reprogramming fibroblasts into iBlastoids, Nature (2021). DOI: 10.1038/s41586-021-03372-y
https://phys.org/news/2021-03-scientists-early-human-embryo-skin.ht...
Mar 18, 2021
Dr. Krishna Kumari Challa
As endangered birds lose their songs, they can't find mates
Male songbirds usually learn their tunes from adult mentors. But when aspiring crooners lack proper role models, they hit all the wrong notes—and have less success attracting mates.
For five years, ecologist Ross Crates has tracked the singing ability and breeding success of critically endangered regent honeyeaters. These distinctive black and yellow birds were once common across Australia, but habitat loss since the 1950s has shrunk their population to only about 300 or 400 wild birds today.
While male birds once formed large winter flocks, now they are sparsely distributed across the landscape, so many fly solo. That means fewer honeyeater mentors are nearby during young birds' impressionable first year.
Song learning in many birds is a process similar to humans learning languages—they learn by listening to other individuals. If you can't listen to other individuals, you don't know what you should be learning.
The researchers found that a significant portion of male birds appear to be learning tunes exclusively from other species they encounter. About 12% of male regent honeyeaters wind up producing mangled versions of songs typically sung by noisy friarbirds and black-faced cuckooshrikes, among other species.
In some species, such as mockingbirds, song mimicry adds flourish to love songs. But the female regent honeyeaters aren't impressed.
Unconventional male singers were less successful in wooing mates, the scientists found in research published Tuesday in the journal Proceedings of the Royal Society B. "We think the females are avoiding breeding and nesting with males that sing unusual songs.
For a population already on the brink of extinction, that's worrisome.
"This research suggests that the loss of a song language once the population reaches a very small size could accelerate their decline
It could be that female honeyeaters aren't even recognizing these unconventional singers as potential partners, and so they're not approaching them. Or it could be that they approach, "but then things go wrong if the males get courtship signals wrong."
Hit the wrong note - Loss of vocal culture and fitness costs in a critically endangered songbird, Proceedings of the Royal Society B (2021). rspb.royalsocietypublishing.or … .1098/rspb.2021.0225
https://phys.org/news/2021-03-honeyeaters-wrong-song.html?utm_sourc...
Mar 18, 2021
Dr. Krishna Kumari Challa
Study finds evidence of 55 new chemicals in people
Scientists at UC San Francisco have detected 109 chemicals in a study of pregnant women, including 55 chemicals never before reported in people and 42 "mystery chemicals," whose sources and uses are unknown.
The chemicals most likely come from consumer products or other industrial sources. They were found both in the blood of pregnant women, as well as their newborn children, suggesting they are traveling through the mother's placenta.
The study will be published March 17, 2021, in Environmental Science & Technology.
These chemicals have probably been in people for quite some time, but our technology is now helping us to identify more of them
The scientific team used high-resolution mass spectrometry (HRMS) to identify man-made chemicals in people.
But, while these chemicals can be tentatively identified using chemical libraries, they need to be confirmed by comparing them to the pure chemicals produced by manufacturers that are known as "analytical standards." And manufacturers do not always make these available.
Mar 18, 2021
Dr. Krishna Kumari Challa
New chemicals -2
The researchers report that 55 of the 109 chemicals they tentatively identified appear not to have been previously reported in people:
http://ucsf.edu/news/2021/03/420061/ucsf-study-finds-evidence-55-ch...
https://phys.org/news/2021-03-evidence-chemicals-people.html?utm_so...
Mar 18, 2021
Dr. Krishna Kumari Challa
The collective movement of nanorobots observed in vivo
Nanobots are machines whose components are at the nano-scale (one-millionth of a millimeter), and can be designed in such a way that they have the ability to move autonomously in fluids. Although they are still in the research and development phase, significant advances are being made toward the use of nanorobots in biomedicine. Their applications are varied, from the identification of tumor cells to the release of drugs in specific locations of the body. Nanorobots powered by catalytic enzymes are among the most promising systems because they are fully biocompatible and can make use of "fuels" already available in the body for their propulsion. However, understanding the collective behavior of these nanorobots is essential to advance towards their use in clinical practice.
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Technology to detect chemicals in fruit and vegetables
An ITMO Ph.D. student with her colleagues from Russia, Spain and Singapore has developed flexible sensing films based on silver nanoparticles that can be used to identify the presence of pesticide residue on the surface of agricultural produce in minutes. The research results were published in Nanoscale.
Mar 18, 2021
Dr. Krishna Kumari Challa
When religious leaders stand in a Q for the vaccine!
The world’s largest vaccine maker, Serum Institute of India, is testing a new virus-like particle vaccine for COVID-19 made with technology licensed from the UK-based SpyBiotech.Credit: Reuters/Amit Dave
Mar 18, 2021
Dr. Krishna Kumari Challa
Cutting emissions: Microwave hot water boiler heating system
https://patents.google.com/patent/US6064047A/en
First microwave-powered home boiler could help cut emissions
‘Drop-in’ replacement for gas boilers may help tackle challenge of cutting emissions from home heating
https://www.theguardian.com/environment/2021/mar/16/first-microwave...
Mar 18, 2021
Dr. Krishna Kumari Challa
Why does DNA spontaneously mutate? Quantum physics might explain.
Quantum mechanics, which rules the world of the teensy-tiny, may help explain why genetic mutations spontaneously crop up in DNA as it makes copies of itself, a recent study suggests.
Quantum mechanics describes the strange rules that govern atoms and their subatomic components. When the rules of classical physics, which describe the big world, break down, quantum comes in to explain. In the case of DNA, classical physics offers one explanation for why changes can suddenly appear in a single rung of the spiraling ladder of DNA, resulting in what's called a point mutation.
In a recent study, published Jan. 29 in the journal Physical Chemistry Chemical Physics, researchers explore another explanation, showing that a quantum phenomenon called proton tunneling can cause point mutations by allowing positively charged protons in DNA to leap from place-to-place. This, in turn, can subtly change the hydrogen bridges that bind the two sides of DNA's double helix, which can lead to errors when it's time for DNA to make copies of itself.
In particular, this subtle change can potentially cause misprints in the DNA sequence, where the wrong "letters" get paired together as the strand replicates, the study authors note. These letters, known as bases, usually pair up in a certain way: A to T and G to C. But proton tunneling could cause some bases to mix-and-match.
https://pubs.rsc.org/en/content/articlelanding/2021/CP/D0CP05781A#!divAbstract
https://www.livescience.com/quantum-physics-dna-mutations.html
Mar 18, 2021
Dr. Krishna Kumari Challa
Neuroscientists identify brain circuit motifs that support short-term memory
Humans have the innate ability to store important information in their mind for short periods of time, a capability known as short-term memory. Over the past few decades, numerous neuroscientists have tried to understand how neural circuits store short-term memories, as this could lead to approaches to assist individuals whose memory is failing and help to devise memory enhancing interventions.
Researchers have recently identified neural circuit motifs involved in how humans store short-term memories. Their findings, published in Nature Neuroscience, suggest that memory-related neural circuits contain recurrently connected modules that independently maintain selective and continuous activity.
Short-term memories are of approximately 10 seconds or so, for example, if you needed to remember a phone number while you looked for a pen to write the number. Individual neurons, however, are very forgetful, as they can only remember their inputs for about 10 milliseconds. It has been hypothesized that if two forgetful neurons were connected to each other, they could continuously remind each other of what they were supposed to remember so that the circuit can now hold information for many seconds.
It was found that neurons tended to be connected in clusters. This means that the circuit was composed of many independent clusters, or modules, that were each able to store short-term memories independently.
Targeted photostimulation uncovers circuit motifs supporting short-term memory. Nature Neuroscience(2021). DOI: 10.1038/s41593-020-00776-3.
https://medicalxpress.com/news/2021-03-neuroscientists-brain-circui...
Mar 19, 2021
Dr. Krishna Kumari Challa
Found in space: Complex carbon-based molecules
Much of the carbon in space is believed to exist in the form of large molecules called polycyclic aromatic hydrocarbons (PAHs). Since the 1980s, circumstantial evidence has indicated that these molecules are abundant in space, but they have not been directly observed.
Now, a team of researchers has identified two distinctive PAHs in a patch of space called the Taurus Molecular Cloud (TMC-1). PAHs were thought to form efficiently only at high temperatures—on Earth, they occur as byproducts of burning fossil fuels, and they're also found in char marks on grilled food. But the interstellar cloud where the research team observed them has not yet started forming stars, and the temperature is about 10 degrees above absolute zero.
This discovery suggests that these molecules can form at much lower temperatures than expected, and it may lead scientists to rethink their assumptions about the role of PAH chemistry in the formation of stars and planets, the researchers say.
B.A. McGuire el al., "Detection of two interstellar polycyclic aromatic hydrocarbons via spectral matched filtering," Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abb7535
Ci Xue et al. Detection of Interstellar HC4NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions, The Astrophysical Journal (2020). iopscience.iop.org/article/10. … 847/2041-8213/aba631
Brett A. McGuire et al. Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH2CN) in TMC-1, The Astrophysical Journal (2020). iopscience.iop.org/article/10. … 847/2041-8213/aba632
Andrew M. Burkhardt et al. Ubiquitous aromatic carbon chemistry at the earliest stages of star formation, Nature Astronomy (2021). DOI: 10.1038/s41550-020-01253-4
https://phys.org/news/2021-03-space-complex-carbon-based-molecules....
Mar 19, 2021
Dr. Krishna Kumari Challa
Enigmatic circling behavior captured in whales, sharks, penguins, and sea turtles
Technological advances have made it possible for researchers to track the movements of large ocean-dwelling animals in three dimensions with remarkable precision in both time and space. Researchers reporting in the journal iScience on March 18 have now used this biologging technology to find that, for reasons the researchers don't yet understand, green sea turtles, sharks, penguins, and marine mammals all do something rather unusual: swimming in circles.
A wide variety of marine megafauna showed similar circling behavior, in which animals circled consecutively at a relatively constant speed more than twice.
This finding is surprising in part because swimming in a straight line is the most efficient way to move about.
Researchers report that some circling events were recorded at animals' foraging areas, suggesting that it might have some benefit for finding food.
It's possible the circling helps the animals to detect the magnetic field to navigate; interestingly, the researchers say, submarines also circle during geomagnetic observations. But it's also possible that the circling serves more than one purpose.
iScience, Narazaki et al.: "Similar circling movements observed across marine megafauna taxa" www.cell.com/iscience/fulltext … 2589-0042(21)00189-9 , DOI: 10.1016/j.isci.2021.102221
https://phys.org/news/2021-03-enigmatic-circling-behavior-captured-...
Mar 19, 2021
Dr. Krishna Kumari Challa
Artificial intelligence system detects errors when medication is self-administered
From swallowing pills to injecting insulin, patients frequently administer their own medication. But they don't always get it right. Improper adherence to doctors' orders is commonplace, accounting for thousands of deaths and billions of dollars in medical costs annually. Researchers now have developed a system to reduce those numbers for some types of medications.
The new technology pairs wireless sensing with artificial intelligence to determine when a patient is using an insulin pen or inhaler, and flags potential errors in the patient's administration method.
Assessment of medication self-administration using artificial intelligence, Nature Medicine (2021). DOI: 10.1038/s41591-021-01273-1
Mar 19, 2021
Dr. Krishna Kumari Challa
Bacteria Behind UTIs Make Their Own DNA Building Blocks From Your Urine
Some infectious bacteria have adapted so well to the human bladder, they appear to make their own DNA using chemicals in our urine.
The urinary tract is a hard place for most bacteria to survive. That's why urine is often said to be sterile, although that's not actually true.
Just like your gut, human urine is home to a community of microbes, known as a microbiota, and while most bacteria that live within it are harmless, sometimes a particular species can tip the scales, causing painful urinary tract infections (UTIs).
Streptococcus agalactiae is a known source of UTIs in some humans, and new research has now revealed how it can survive in such an unfriendly environment.
In a healthy human body, urine should be relatively low in the four nucleobases making up DNA's code, which are broken down into nitrogenous compounds and excreted out.
Sequencing the S. agalactiae genome, scientists have now found a key, specialized gene, which allows the bacterium to exploit the presence of other compounds in our urine to produce at least one of these bases - guanine - in order for it to survive.
Similar genes have also recently been found in Escherichia coli (E. coli), which is the most common offender of human UTIs.
Usually, in the gut or the blood, E. coli and Streptococcus scavenge for certain chemicals they need to make DNA, borrowing products like guanine from our own bodies. In the urinary tract, however, these essential building blocks are ultimately broken down into uric acid, which means they are not as easy to find.
It's a tough situation, and it means both E. coli and Streptococcus must synthesize their own chemical bases if they want to grow and reproduce.
"It's basically a survival strategy to colonize the urine, an environment that not many organisms can live in
It seems to be a common strategy among species of bacteria that make up the microbiome of the urine."
In the study, scientists used mice to show how essential this specialized gene, known as guaA, truly is. Collecting Streptococcus strains from several individuals, researchers compared a normal S. agalactiae infection with a form of the bacterium deficient in guaA.
Microbes that were unable to create their own guanine were unable to colonize the bladder of mice to the same extent. The same thing was found when researchers used synthetic human urine.
This suggests guaA is essential for a Streptococcus infection to take hold in the bladder, not just in mice but also in us.
https://www.nature.com/articles/s41396-021-00934-w
https://www.sciencealert.com/bacteria-behind-utis-create-their-own-...
Mar 19, 2021
Dr. Krishna Kumari Challa
Long COVID Symptoms Are Vanishing For Some Vaccinated Patients, And We Don't Know Why
A woman who had long COVID said her symptoms were gone 36 hours after getting her second dose of COVID-19 vaccine, according to The Washington Post.
Arianna Eisenberg, 34, said she experienced muscle pains, insomnia, fatigue, and brain fog for eight months after getting sick. These symptoms are typical of what has become known as "long COVID".
But 36 hours after receiving a second dose of COVID-19 vaccine, her symptoms were gone, the Post reported.
Eisenberg's story is one of several describing a similar effect.
The Philadelphia Inquirer and the Huffington Post also reported on people for whom long COVID symptoms improved after vaccination.
Daniel Griffith, an infectious diseases clinician and researcher at Columbia University, told The Verge on March 2 that around a third of his long COVID patients reported that they were feeling better after the vaccine.
In a YouTube video, Gez Medinger, a science journalist who reports on long COVID, did a survey of 473 long haulers among support groups on Facebook, The Verge reported, around a third of whom saw their symptoms improve after vaccination.
One small study from the UK's University of Bristol, which has not been peer reviewed, looked at giving vaccines to people with long COVID-19 symptoms, per the Washington Post report.
The scientists gave the vaccine to 44 COVID long-haulers, and compared their reaction to a group of long-haulers who didn't get the vaccine.
They reported that those who had received the vaccine had a "small overall improvement in long COVID symptoms".
https://www.sciencealert.com/woman-with-months-of-long-covid-finds-...
This article was originally published by Business Insider.
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Mar 19, 2021
Dr. Krishna Kumari Challa
Chemists gain new insights into the behavior of water in an influenza virus channel
In a new study of water dynamics, a team of MIT chemists led by Professor Mei Hong, in collaboration with Associate Professor Adam Willard, has discovered that water in an ion channel is anisotropic, or partially aligned. The researchers' data, the first of their kind, prove the relation of water dynamics and order to the conduction of protons in an ion channel. The work also provides potential new avenues for the development of antiviral drugs or other treatments.
Members of the Hong lab conducted sophisticated nuclear magnetic resonance (NMR) experiments to prove the existence of anisotropic water in the proton channel of the influenza M virus, while members of the Willard group carried out independent all-atom molecular dynamics simulations to validate and augment the experimental data. Their study, of which Hong was the senior author, was published in Communications Biology
The influenza B virus protein BM2 is a protein channel that acidifies the virus, helping it to release its genetic material into infected cells. The water in this channel plays a critical role in helping the influenza virus become infectious, because it facilitates proton conduction inside the channel to cross the lipid membrane.
This new study has provided the missing link in a full understanding of the mixed hydrogen-bonded chain between water and histidine inside the M2 channel. To curb the flu virus protein, the channel would have to be plugged with small molecules—i.e., antiviral drugs—so that the water pathway would be broken.
the researchers were able to observe that the water network has fewer hydrogen-bonding bottlenecks in the open state than in the closed state. Thus, faster dynamics and higher orientational order of water molecules in the open channel establish the water network structure that is necessary for proton hopping and successful infection on the virus' part.
When a flu virus enters a cell, it goes into a small compartment called the endosome. The endosome compartment is acidic, which triggers the protein to open its water-permeated pathway and conduct the protons into the virus. Acidic pH has a high concentration of hydrogen ions, which is what the M2 protein conducts. Without the water molecules relaying the protons, the protons will not reach the histidine, a critical amino acid residue. The histidine is the proton-selective residue, and it rotates in order to shuttle the protons carried by the water molecules. The relay chain between the water molecules and the histidine is therefore responsible for proton conduction through the M2 channel. Therefore, the findings indicated in this research could prove relevant to the development of antiviral drugs and other practical applications.
Martin D. Gelenter et al. Water orientation and dynamics in the closed and open influenza B virus M2 proton channels, Communications Biology (2021). DOI: 10.1038/s42003-021-01847-2
https://phys.org/news/2021-03-chemists-gain-insights-behavior-influ...
Mar 20, 2021
Dr. Krishna Kumari Challa
Bioengineers learn the secrets to precisely turning on and off genes
In a recent study , scientists have shown how to simultaneously harness multiple forms of regulation in living cells to strictly control gene expression and open new avenues for improved biotechnologies.
Engineered microbes are increasingly being used to enable the sustainable and clean production of chemicals, medicines and much more. To make this possible, bioengineers must control when specific sets of genes are turned on and off to allow for careful regulation of the biochemical processes involved.
Although turning on or off a gene sounds simple, getting a living cell to do it on command is a real challenge. Every cell is slightly different, and the processes involved are not 100 percent reliable. To solve this issue, the team took inspiration from nature where key events are often controlled by multiple processes simultaneously.
The team showed that by using this type of multi-level regulation, they could create some of the most high-performance switches for gene expression built to date. They demonstrated that even when used outside of living cells, these multi-level systems offered some of the most stringent control over gene expression yet seen.
Harnessing the central dogma for stringent multi-level control of gene expression, Nature Communications (2021).
https://phys.org/news/2021-03-bioengineers-secrets-precisely-genes....
Mar 20, 2021
Dr. Krishna Kumari Challa
Researchers find evidence of elusive Odderon particle
For 50 years, the research community has been hunting unsuccessfully for the so-called Odderon particle. Now, a Swedish-Hungarian research group has discovered the mythical particle with the help of extensive analysis of experimental data from the Large Hadron Collider at CERN in Switzerland.
In 1973, two French particle physicists found that, according to their calculations, there was a previously unknown quasi-particle. The discovery sparked an international hunt.
The Odderon particle is what briefly forms when protons collide in high-energy collisions, and in some cases do not shatter, but bounce off one another and scatter. Protons are made up of quarks and gluons, that briefly form Odderon and Pomeron particles.
And now a research team, involving researchers from Lund University, has succeeded in identifying the Odderon in connection with an advanced data analysis study at the particle accelerator CERN.
T. Csörgő et al. Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies, The European Physical Journal C (2021). DOI: 10.1140/epjc/s10052-021-08867-6
https://phys.org/news/2021-03-evidence-elusive-odderon-particle.htm...
Mar 20, 2021
Dr. Krishna Kumari Challa
Past Climate Change: Geologists Explore the History of Cave Ice
Mar 20, 2021
Dr. Krishna Kumari Challa
Covid reinfection rare, more common over 65: study
Surviving Covid-19 protects most people against reinfection for at least six months, but elderly patients are more likely to be laid low by the virus a second time, researchers reported Thursday. An assessment of reinfection rates in Denmark last year showed that just over half a percent of people who tested positive for Covid during the first wave from March to May did so again during the second wave, from September to December. Among these, the researchers found that initial infection with Covid-19 was likely to bestow 80 percent protection from reinfection among under-65s, but that dropped to just 47 percent in older people. "We did not identify anything to indicate that protection against reinfection declines within six months of having Covid-19, say the researchers.
The researchers said this meant that initial infection with Covid-19 was likely to bestow 80 percent protection from reinfection among under 65s.
For those aged over 65, however, the protection level diminished sharply.
Of the more than 1,900 over-65s who tested positive during the first wave, 17 (0.88 percent) tested positive again during the second.
This compared to 1,866 out of more than 90,000 over-65s (two percent) who tested positive during the second wave but not the first -- a protection difference of 47 percent.
The study confirms what a number of others appeared to suggest: reinfection with Covid-19 is rare in younger, healthy people.
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Mar 20, 2021