Mass extinction: A warning that this can happen now too
The end-Permian mass extinction event of roughly 252 million years ago—the worst such event in earth's history—has been linked to vast volcanic emissions of greenhouse gases, a major temperature increase, and the loss of almost every species in the oceans and on land.
Now, it seems that even the lakes and rivers were no safe havens. A recent study published by an international team of researchers has identified a new cause of extinction during extreme warming events: toxic microbial blooms.
In a healthy ecosystem, microscopic algae and cyanobacteria provide oxygen to aquatic animals as a waste product of their photosynthesis. But when their numbers get out of control, these microbes deplete free oxygen, and even release toxins into the water. By studying the fossil, sediment, and chemical records of rocks near Sydney, Australia, the researchers discovered that several pulses of bloom events had occurred soon after the first volcanic rumblings of the end-Permian mass extinction. Once the bottom-feeder animals, or "detritivores," were killed off, there was no one left to keep the microbes in check. The fresh water systemsthen seethed with algae and bacteria, delaying the recovery of animals for perhaps millions of years.
We're seeing more and more toxic algae blooms in lakes and in shallow marine environments that's related to increases in temperature and changes in plant communities which are leading to increases in nutrient contributions to freshwater environments. So, a lot of parallels to today. The volcanism was a source of CO2in the past but we know that the rate of CO2input that was seen back then was similar to the rate of CO2increases we're seeing today because of anthropogenic effects.
We can get a sense of how much climate has changed in the past, what the extremes are, how fast it can change, what the causes of climate change are and that gives us a nice backdrop for understanding what's happening today. The end-Permian is one of the best places to look for parallels with what's happening now.
The other big parallel is that the increase in temperature at the end of the Permian coincided with massive increases in forest fires. One of the things that that destroyed whole ecosystems was fire, and we're seeing that right now in several places .
We should be concerned like hell!
Chris Mays et al, Lethal microbial blooms delayed freshwater ecosystem recovery following the end-Permian extinction, Nature Communications (2021). DOI: 10.1038/s41467-021-25711-3
Antibodies from original strain COVID-19 infection don't bind to variants, study finds
People infected with the original strain of the virus that causes COVID-19 early in the pandemic produced a consistent antibody response, making two main groups of antibodies to bind to the spike protein on the virus’s outer surface. However, those antibodies don’t bind well to newer variants, a new study found.
Researchers found that many antibody sequences converged into two main groups, indicating a consistent human immune response to the virus. The researchers studied the convergent antibodies’ ability to bind to several variants and found that they no longer bound to some. The finding has implications for the ability of new variants to reinfect people who contracted earlier versions of the virus, as well as for the continuing efficacy of vaccines and the design of possible vaccine boosters.
Even though this antibody response is very common with the original strain, it doesn’t really interact with variants. That, of course, raises the concern of the virus evolving to escape the body’s main antibody response. Some antibodies should still be effective – the body makes antibodies to many parts of the virus, not only the spike protein – but the particular groups of antibodies that we saw in this study will not be as effective.
The researchers said they would like to conduct similar studies characterizing antibody responses to delta and other variants, to see whether they also produce a convergent response and how it differs from the original strain.
It is expected that the antibody response to those variants would be quite different.
Will Indian researchers lose free access to scientific papers?
It’ll depend on the outcome of an ongoing case against SciHub and LibGen websites in the Delhi High Court.
On December 21, 2020, academic publishers Elsevier Ltd, Wily Pvt Ltd, and the American Chemical Society sued websites SciHub and Library Genesis, also known as LibGen, for copyright infringement in the Delhi High Court, demanding that ISP providers permanently block them in India.
These websites are a primary source for researchers in India, making available for free thousands of otherwise paywalled research papers. Because, asSciHubnotes, “Research should be free to read.” Having intellectual property restrictions in research throttle access to and flow of knowledge while science can only progress when it’s widely read and debated.
Elsevier owns over 2,600 journals, including theLancet,and all of them are paywalled withsubscription ratesgoing up to thousands of dollars, making the latest knowledge hard to access for researchers.
Engineers create light-emitting plants that can be charged repeatedly
Using specialized nanoparticles embedded in plant leaves, MIT engineers have created a light-emitting plant that can be charged by an LED. After 10 seconds of charging, plants glow brightly for several minutes, and they can be recharged repeatedly.
These plants can produce light that is 10 times brighter than the first generation of glowing plants that the research group reported in 2017.
Creating ambient light with the renewable chemical energy of living plants is a bold idea. It represents a fundamental shift in how we think about living plants and electrical energy for lighting.
The particles can also boost the light production of any other type of light-emitting plant, including those the researchers originally developed. Those plants use nanoparticles containing the enzyme luciferase, which is found in fireflies, to produce light. The ability to mix and match functional nanoparticles inserted into a living plant to produce new functional properties is an example of the emerging field of "plant nanobionics."
Their first generation of light-emitting plants contained nanoparticles that carry luciferase and luciferin, which work together to give fireflies their glow. Using these particles, the researchers generated watercress plants that could emit dim light, about one-thousandth the amount needed to read by, for a few hours.
In the new study, Strano and his colleagues wanted to create components that could extend the duration of the light and make it brighter. They came up with the idea of using a capacitor, which is a part of an electrical circuit that can store electricity and release it when needed. In the case of glowing plants, a light capacitor can be used to store light in the form of photons, then gradually release it over time.
To create their "light capacitor," the researchers decided to use a type of material known as a phosphor. These materials can absorb either visible or ultraviolet light and then slowly release it as a phosphorescent glow. The researchers used a compound called strontium aluminate, which can be formed into nanoparticles, as their phosphor. Before embedding them in plants, the researchers coated the particles in silica, which protects the plant from damage.
The particles, which are several hundred nanometers in diameter, can be infused into the plants through the stomata—small pores located on the surfaces of leaves. The particles accumulate in a spongy layer called the mesophyll, where they form a thin film. A major conclusion of the new study is that the mesophyll of a living plant can be made to display these photonic particles without hurting the plant or sacrificing lighting properties, the researchers say.
This film can absorb photons either from sunlight or an LED. The researchers showed that after 10 seconds of blue LED exposure, their plants could emit light for about an hour. The light was brightest for the first five minutes and then gradually diminished. The plants can be continually recharged for at least two weeks.
Pavlo Gordiichuk et al, Augmenting the living plant mesophyll into a photonic capacitor, Science Advances (2021). DOI: 10.1126/sciadv.abe9733
Nano-scale discovery could help to cool down overheating in electronics
A team of physicists solved the mystery behind a perplexing phenomenon in the nano realm: why some ultra-small heat sources cool down faster if you pack them closer together. The findings could one day help the tech industry design faster electronic devices that overheat less.
Often, heat is a challenging consideration in designing electronics. You build a device then discover that it's heating up faster than desired.
In 2015, physicists were experimenting with bars of metalthat were many times thinner than the width of a human hair on a silicon base. When they heated those bars up with a laser, something strange occurred.
They behaved very counterintuitively. These nano-scale heat sources do not usually dissipate heat efficiently. But if you pack them close together, they cool down much more quickly.
Now, the researchers know why it happens.
In the new study, they used computer-based simulations to track the passage of heat from their nano-sized bars. They discovered that when they placed the heat sources close together, the vibrations of energy they produced began to bounce off each other, scattering heat away and cooling the bars down.
The group's results highlight a major challenge in designing the next generation of tiny devices, such as microprocessors or quantum computer chips: When you shrink down to very small scales, heat does not always behave the way you think it should.
Directional thermal channeling: A phenomenon triggered by tight packing of heat sources, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2109056118
Yeast and bacteria together biosynthesize plant hormones for weed control
Plants regulate their growth and development using hormones, including a group called strigolactones that prevent excessive budding and branching. For the first time, scientists have synthesized strigolactones from microbes.
Strigolactones also helpplant rootsform symbiotic relationships with microorganisms that allow the plant to absorb nutrients from the soil. These two factors have led to agricultural interest in using strigolactones to control the growth of weeds and root parasites, as well as improving nutrient uptake.
These root-extruding compounds don't come without risks. They also stimulate germination of witchweeds and broomrapes, which can cause entire crops of grain to fail, making thorough research essential prior to commercial development. Scientists are still learning about the physiological roles played by this diverse group of hormones inplants. Until recently, manufacturing pure strigolactones for scientific study has been difficult and too costly for agricultural use.
The new work provides a unique platform to investigate strigolactone biosynthesis and evolution, and it lays the foundation for developing strigolactone microbial bioproduction processes as alternative sourcing.
Researchers directed a group that inserted plant genes associated with strigolactone production into ordinary baker's yeast and nonpathogenic Escherichia coli bacteria that together produced a range of strigolactones.
Sheng Wu et al, Establishment of strigolactone-producing bacterium-yeast consortium, Science Advances (2021). DOI: 10.1126/sciadv.abh4048
The Placebo Effect Is an Amazing Illusion, But That Doesn't Mean It's Medicine
Placebo is a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment.
The placebo is one ofscience's greatest mysteries. The pill that isn't a pill. The medical illusion that somehow becomes real.
But just because the placebo effect occasionally deliversunexpected outcomesdoesn't mean we should overestimate how powerful it is – nor try to find a place for it in the medical care of patients, scientists are now warning.
In a newperspective article, researchers argue that recent suggestions placebos could play a role in clinical care are unfounded, and are based on flawed evidence.
Much of the current discourse on placebo seems to focus more on enshrining placebos as mysterious and highly effective and less on making a practical difference to patient care and outcomes.
Observations of the placebo effect can betraced back to the 18th century, and the reputation of the placebo has grown ever since: the idea that an inert, sham treatment, taken unknowingly by a patient, can sometimes deliver therapeutic effects like the real thing.
That reputation is mostly underserved. A Cochrane review of placebos considered 234 trials and concluded that, in general, placebos do not produce major health benefits, except for some small and inconsistent effects on self-reported outcomes such as pain or nausea," the researchers explain.
Placebos remain important forclinical trialsbecause they help achieve blinding and, thus, control of bias,"the team writes.
"When administered in a blinded fashion, a placebo will provide a small effect, but the real treatment will normally provide better outcomes for the patient… It may be better to dismiss placebos and instead manage patients with evidence-based treatments., they conclude.
In both a mouse model and the hospital records of more than 3 million children, researchers found a connection between strong immune activation in males and later symptoms of autism spectrum disorder.
While researchers have found plenty of gene variants that seem to increase the risk of an autism diagnosis, it’s not clear why some people carrying these mutations develop autism spectrum disorders and some do not. In a study published today (September 17) in Science Advances, researchers point to a potential answer: severe infections during early childhood. After an early immune challenge, male mice with a mutated copy of the tuberous sclerosis complex 2(Tsc2) gene developed deficits in social behavior linked to changes in microglia, the immune cells of the brain. And an analysis of the hospital records of more than 3 million children showed that children, particularly boys, who were hospitalized for infections between ages 18 months and four years were more likely that healthy peers to receive a future autism spectrum disorder (ASD) diagnosis.
Inhibiting targets of SARS-CoV-2 proteases can block infection, study shows
Researchers have shown how SARS-CoV-2 viral proteases attack the host cell, and how this can be targeted to stop virus replication in cell culture using existing drugs.
The new findings, published today in Nature Communications, offer a powerful resource to understand proteolysis in the context of viral infection, and to inform the development of targeted strategies to inhibit the virus that causes COVID-19.
Both viral and cellular proteases play a crucial role in SARS-CoV-2 replication, and inhibitors targeting proteases have already shown success at inhibiting SARS-CoV-2 in cell culture models.
In this study, researchers used a mass spectrometry approach to study proteolytic cleavage events during SARS-CoV-2 infection.
The team found previously unknown cleavage sites in multipleviral proteins, including major antigenic proteins S and N, which are the main targets for vaccine and antibody testing efforts.
They discovered significant increases in cellular cleavage events consistent with cleavage by SARS-CoV-2 main protease (Mpro) and identified 14 potential high-confidence substrates of the main and papain-like proteases, validating a subset within vitroassays.
They went on to show that siRNA depletion of these cellular proteins inhibits SARS-CoV-2 replication, and that drugs targeting two of these proteins: the tyrosine kinase SRC and Ser/Thr kinase MYLK, showed a dose-dependent reduction in SARS CoV-2 titres.
Both Bafetinib (an experimental cancer drug) and Sorafenib (an approved drug used to treat kidney and liver cancer) showed SARS-CoV-2 inhibition at concentrations that did not result in cytotoxicity in a human cell line model of infection.
Characterising proteolysis during SARS-CoV-2 infection identifies viral cleavage sites and cellular targets with therapeutic potential, Nature Communications (2021). DOI: 10.1038/s41467-021-25796-w
Rock shape should be given greater consideration in rockfall risk assessments
The shape of rocks is a key factor in assessing rockfall hazard. This is the conclusion of a new study from the Institute for Snow and Avalanche Research.
Rockfall is a very real threat in an Alpine country like Switzerland. In order to assess the hazard at a given location and plan protective measures, engineering firms use computer models to calculate how far falling rocks can roll. However, the models are not yet able to adequately take into account the extent to which the mass, size or shape of a rock influences its movement. This would require real-world measurement data to be fed into the models, but until now such data were only available sporadically, since no systematic rockfallstudies had been conducted.
First comprehensive experiments
That has now changed after researchers spent over four years carrying out rockfall experiments. This has allowed them to compile the largest set of measurement data to date.
The researchers used artificial rocks in the form of concrete blocks fitted with sensors, which they rolled down a slope near the Flüela Pass in the Swiss canton of Grisons. They compared different shapes and masses, reconstructed the complete trajectories and determined speeds, jump heights and runout zones (see info box). They have just published their results in the scientific journal Nature Communications.
The most significant finding is that the direction a rock rolls in depends much more on its shape than on its mass. While cube-shaped boulders plunge straight down the line of greatest slope, wheel-shaped rocks often pull away to one side and so may threaten a much wider area at the base of the slope. "This needs to be taken into consideration when assessing danger zones, but also when determining the location and dimensions of rockfall nets.
Because wheel-like rocks hit rockfall nets with their narrow side, their energy is concentrated on a much smaller area than is the case with cube-like rocks—so protective nets need to be stronger.
The data set is also available on the EnviDat platform, where it is freely accessible to other research groups. They can use it to calibrate their own algorithms or to develop new, more accurate models providing enhanced protection against rockfall.
Andrin Caviezel et al, The relevance of rock shape over mass—implications for rockfall hazard assessments, Nature Communications (2021). DOI: 10.1038/s41467-021-25794-y
Satellite swarms may outshine the night sky’s natural constellations
“Mega-constellations” from those satellites will be visible to the naked eye, simulations suggest
A few years back somebody asked me from the art field, "If You 're asked to make a science-art installation, what would it be?" My instant answer was, "Groups of satellites in the night sky that shine like star constellations and also help the mankind".
"Wow!" was that person's reaction.
But, now that reply of mine is going to be revisited. Why? Companies like SpaceX and Amazon have launched hundreds of satellites into low orbits since 2019, with plans to launch thousands more in the works — a trend that’s alarming astronomers. The goal of these satellite “mega-constellations” is to bring high-speed internet around the globe, but these bright objects threaten to disrupt astronomers’ ability to observe the cosmos.
Now, a new simulation of the potential positions and brightness of these satellites shows that, contrary to earlier predictions, casual sky watchers will have their view disrupted, too. And parts of the world will be affected more than others.
Flat, smooth surfaces on satellites can reflect sunlight depending on their position in the sky. Earlier research had suggested that most of the new satellites would not be visible with the naked eye.
There are currently about 7,890 objects in Earth orbit, about half of which are operational satellites, according to the U.N. Office for Outer Space Affairs. But that number is increasing fast as companies launch more and more satellites . In August 2020, there were only about 2,890 operational satellites.
the researchers computed how many satellites will be in the sky at different times of year, at different hours of the night and from different positions on Earth’s surface. They also estimated how bright the satellites were likely to be at different hours of the day and times of the year.
The simulations showed that “the way the night sky is going to change will not affect all places equally,” Lawler says. The places where naked-eye stargazing will be most affected are at latitudes 50° N and 50° S, regions that cross lower Canada, much of Europe, Kazakhstan and Mongolia, and the southern tips of Chile and Argentina, the researchers found.
The geometry of sunlight in the summer means there will be hundreds of visible satellites all night long. It’s bad everywhere, but it’s worse there.
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A few visible satellites can be a fun spectacle. Astronomers have been meeting with representatives from private companies, as well as space lawyers and government officials, to work out compromises and mitigation strategies. Companies have been testing ways to reduce reflectivity, like shading the satellites with a “visor.” Other proposed strategies include limiting the satellites to lower orbits, where they move faster across the sky and leave a fainter streak in telescope images. Counterintuitively, lower satellites may be better for some astronomy research. “They move out of the way quick.”
But that lower altitude strategy will mean more visible satellites for other parts of the world, and more that are visible to the naked eye.
There are some latitudes on Earth where no matter what altitude you put your satellites at, they’re going to be all over the darn place. The only way out of this is fewer satellites.
There are currently no regulations concerning how bright a satellite can be or how many satellites a private company can launch. Scientists are grateful that companies are willing to work with them, but think that their cooperation is voluntary. Efforts are under way to bring the issue to the attention of the United Nations and to try to use existing environmental regulations to place limits on satellite launches.
Salty Diet Helps Gut Bugs Fight Cancer in Mice: Study
A high-salt diet suppressed the growth of tumors in a mouse model of melanoma, apparently because of an interplay between the gut microbiome and natural killer cells.
Salt may not be good for your BP, but .....
In mice, a diet high in salt suppresses tumor growth—but only when gut microbes are there to stimulate immune cells, a September 10 study inScience Advancesreports. The findings raise tantalizing questions about the role of diet and gut microbes in human cancers, and may point to new avenues for therapeutic development.
While the study isn’t the first to connect a high-salt diet to shrinking tumors, the authors have shown a unique mechanistic role of high salt induced gut microbiome changes as the central phenomenon behind their observed anti-cancer effect.
The researchers pursued this line of inquiry because previous research had linked high salt intake with autoimmune diseases, suggesting that increased salt stimulates immune cells. Meanwhile, tumors are well known to grow in immune-suppressive environments. So they thought, “If we put salt in the mice’s diet, maybe [the immune system in] the tumor environment becomes activated,” suppressing cancerous growth.
a 2019 Frontiers in Immunologystudy from a European team led by Hasselt University immunologist Markus Kleinewietfeld reported that high-salt diets inhibited tumor growth in mice. No researchers carried out similar experiments, implanting mice with B16F10 skin melanoma cells and then feeding the tumor transplant mice diets with different salt levels, they got similar results: tumors grew slower in mice who were fed a high-salt diet.
Infants have more microplastics in their feces than adults, study finds
Microplastics—tiny plastic pieces less than 5 mm in size—are everywhere, from indoor dust to food to bottled water. So it's not surprising that scientists have detected these particles in the feces of people and pets. Now, in a small pilot study, researchers reporting in ACS' Environmental Science & Technology Lettersdiscovered that infants have higher amounts of one type of microplastic in their stool than adults. Health effects, if any, are uncertain.
Little is known about the magnitude of human exposure to microplastics or their health effects. Although microplastics were once thought to pass harmlessly through the gastrointestinal tract and exit the body, recent studies suggest that the tiniest pieces can cross cell membranes and enter the circulation. In cells and laboratory animals, microplastic exposure can cause cell death, inflammation and metabolic disorders.
The researchers used mass spectrometry to determine the concentrations of PET and PC microplastics in six infant and 10 adult feces samples collected from New York state, as well as in three samples of meconium (a newborn infant's first stool). All samples contained at least one type of microplastic. Although average levels of fecal PC microplastics were similar between adults and infants, infant stool contained, on average, more than 10 times higher PET concentrations than that of adults.
Infants could be exposed to higher levels of microplastics through their extensive use of products such as bottles, teethers and toys, the researchers say.
Occurrence of Polyethylene Terephthalate and Polycarbonate Microplastics in Infant and Adult Feces, Environmental Science & Technology Letters (2021). pubs.acs.org/doi/abs/10.1021/acs.estlett.1c00559
Global cancer risk from burning organic matter comes from unregulated chemicals
Whenever organic matter is burned, such as in a wildfire, a power plant, a car's exhaust, or in daily cooking, the combustion releases polycyclic aromatic hydrocarbons (PAHs)—a class of pollutants that is known to cause lung cancer.
There are more than 100 known types of PAH compounds emitted daily into the atmosphere. Regulators, however, have historically relied on measurements of a single compound, benzo(a)pyrene, to gauge a community's risk of developing cancer from PAH exposure. Now MIT scientists have found that benzo(a)pyrene may be a poor indicator of this type of cancer risk.
In a modeling study appearing today in the journalGeoHealth,the team reports that benzo(a)pyrene plays a small part—about 11 percent—in the global risk of developing PAH-associated cancer. Instead, 89 percent of that cancer risk comes from other PAH compounds, many of which are not directly regulated.
Interestingly, about 17 percent of PAH-associated cancer risk comes from "degradation products"—chemicals that are formed when emitted PAHs react in the atmosphere. Many of these degradation products can in fact be more toxic than the emitted PAH from which they formed.
Jamie M. Kelly et al, Global Cancer Risk from Unregulated Polycyclic Aromatic Hydrocarbons, GeoHealth (2021). DOI: 10.1029/2021GH000401
Hairdressers say people are having allergic reactions to hair dye due to COVID
Covid-19: New allergic reactions to hair dye reported
It's important to always get a patch test before using a beauty product
News that there is a link between COVID-19 and allergies to hair dye is being reported more and more. Over the past year, more and more hairdressers have noticed a worrying increase in customers suffering allergic reactions to hair dye after testing positive for COVID-19.
Hairdressers report customers developing rashes and burns after using hair dye, even if it's a product they've used before. Now, according to the BBC, the trade body that represents hairdressers and beauticians is warning professionals to carry out additional patch tests to avoid facing legal action. Patch tests require customers to sample the product on their skin 24-48 hours before their appointment to see how they react.
Winged microchip is smallest-ever human-made flying structure
Inspired by the way trees like maples disperse their seeds using little more than a stiff breeze, researchers developed a range of tiny flying microchips, the smallest one hardly bigger than a grain of sand.
This flying microchip or 'microflier' catches wind and spins like a helicopter towards the ground.
The microfliers can be packed with ultra-miniaturized technology, including sensors, power sources, antennas for wireless communication, and even embedded memory for data storage.
Reprogramming heart muscle cells to repair damage from heart attacks
A team of researchers has found that it is possible to reprogram heart muscle to repair damaged tissue. In their paper published in the journal Science, the group describes their approach to repairing damaged hearts in mice and how well it worked when tested.
There are two main kinds of heartattack. The first occurs when something prevents the heart from beating. The second occurs whenblood flowis restricted to parts of the heart, preventing the muscle in that area from beating. The first kind is generally fatal unless the heart can be restarted very quickly. The second is generally less serious, but can leave permanent, debilitating scarring. In this new effort, the researchers have found a way to prevent such scarring—at least in mice.
The work built on prior research that showed that in the case of a baby experiencing heart damage in utero, the heart can repair itself because the cardiomyocyte cells are in a state that allows rejuvenation. This is not the case after birth or later in life, as the cardiomyocytes have no ability to regenerate. After several years of effort, the researchers discovered a way to get adult cardiomyocytes to revert back to fetal-like cardiomyocytes by reprogramming them using the Yamanaka factors c-Myc, Klf4, Sox2 and Oct4. Their research showed that such factors express for cell renewal. The reprogramming also featured an on/off switch using the antibiotic doxycycline.
The researchers then tested their approach by giving mice with reprogrammed cells doxycycline just prior to and after inducing heart damage. They found that under both scenarios, heart regeneration occurred along with heart function improvement. The researchers also tried giving similar test micedoxycycline six days after experiencing heart damageand found it had no impact. Thus, the window of repair is short. Further testing also showed that if doxycycline was administered for too long a period, cancerous tumors developed. Much more work is required to determine if a similar approach might work for humans, and if it can be done without increasing the risk of cancer.
Yanpu Chen et al, Reversible reprogramming of cardiomyocytes to a fetal state drives heart regeneration in mice, Science (2021). DOI: 10.1126/science.abg5159
Scientists suggest pregnant women only take paracetamol/acetaminophen only if medically necessary
A group of 13 scientists has penned a consensus statement regarding the use of paracetamol/acetaminophen (APAP) by pregnant women. In their paper, published in the journal Nature Reviews Endocrinology, the group suggests that pregnant women only take paracetamol/acetaminophen only if it is medically necessary. Nature has also published an Editorial in the same journal issue, outlining the consensus statement and noting that its authors are not calling for a ban on the drug being used, instead they are suggesting that it be taken more cautiously by pregnant women because of a possible risk of birth defects.
In their paper, the authors note that research over the past several years has shown that it is possible under some circumstances for APAP to alter fetal development which in some cases can lead to problems with neurological, urological and reproductive disorders in the baby—they looked at 29 studies and found evidence of birth defects in 26 of them. They call for more research to be conducted to better understand possible problems with the drug being used by pregnant women. They also acknowledge—as do several experts in a reaction piece published on the Science Media Centre, site—that APAP is the only drug currently available for pain management for pregnant women. And they point out that medical use of APAP is generally warranted when the mother experiences problems that can negatively impact her baby—such as having a fever. But they also note that use of APAP by pregnant women appears to have crept up into general use as it has gained a reputation as being safe to use as an all-purpose analgesic.
The authors of the consensus statement further suggest that their intent in publishing such an article is to bring renewed and more focused attention to the possibility of APAP use leading to certain birth defects and the conditions under which they might arise. They note that current research has shown, for example, that the possibility of harm seems to increase as the duration of APAP use goes up. Thus, they suggest pregnant women consider using the drug for short term pain management, rather than as a long-term solution.
Ann Z. Bauer et al, Paracetamol use during pregnancy—a call for precautionary action, Nature Reviews Endocrinology (2021). DOI: 10.1038/s41574-021-00553-7
Human cells are usually diploid—they contain two sets of chromosome. Cells in which one chromosome is missing from the duplicated chromosome set are generally not viable. For a long time, the mechanisms responsible for the loss of viability were unknown. New research now throws some light on it.
Monosomy occurs when chromosomes are incorrectly distributed during routine cell division and cells subsequently lack one chromosome in an otherwise double (diploid) set. The only form of this deviation in chromosome number (aneuploidy) that human cells can survive is known as Turner syndrome. The hallmark of the hereditary disease, which occurs in women: only one of the two X sex chromosomes is present. However, what happens in human somatic cells that are missing other than sex chromosome had not been explored until now, because monosomic cells are generally not viable.
When monosomy occurs, the protein 'p53," encoded by the so-called tumor suppressor gene TP53, ensures that the cell cycle stops. In other words, the cells stop dividing. Therefore, researchers have switched off this gene in one part of their cell lines, which were originally derived from human retina cell lines, to downregulate the production of the encoded protein. Thus, for the first time, they succeeded in generating stable monosomic cell lines for research purposes.
The research team subsequently focused on the effects of monosomy on proliferation (cell growth/multiplication), genomic stability and how chromosome loss affects the amount of mRNAs and proteins (transcriptome and proteome, respectively). They we observed reduced levels of cytoplasmic ribosomal proteins and reduced protein synthesis (protein translation) in all monosomal cell lines. Accordingly, they hypothesize that chromosome loss impairs ribosomal biogenesis and thereby cellular proliferation. They also showed that this change triggers cell cycle arrest and or senescence via the p53 signaling pathway.
The findings also shed light on the link between cancer and monosomy. Recurrent loss of an entire chromosome or chromosome arm is common in certain tumors, such as neuroblastoma, lung cancer, and myeloid malignancies.
Since monosomies are viable only without p53, scientists predicted that the cancers with monosomy must have defective p53 pathway. The analysis of scientific databases of cancer-related changes, such as "The Cancer Genome Atlas (TCGA)' and "Cancer Cell Lines Encyclopedia (CCLE)", indeed revealed a strong association of monosomy with p53 inactivation and ribosomal pathway impairment.
Narendra Kumar Chunduri et al, Systems approaches identify the consequences of monosomy in somatic human cells, Nature Communications (2021). DOI: 10.1038/s41467-021-25288-x
The research team also performed a systematic transcriptome and proteome analysis of monosomic cell lines in comparison to their parental cell lines—i.e., the quantification of all messenger RNAs (mRNAs) transcribed based on DNA, as well as the quantification of all proteins in the cells. As expected, this showed that the expression of genes localized on the monosome was reduced.
Yet, teh researchers observed the lower levels in only 20 percent of the encoded proteins. They suspect that gene dosage effects came into play here. The cells need to return to their 'natural' diploid protein levels to sustain their function and thus compensate for the chromosome loss. Scientists envision two possible scenarios: First, translation of mRNAs encoded using the genes could be selectively increased, or second, proteindegradation is reduced. These results suggest that cells use multiple pathways to mitigate the consequences of altered gene expression.
In summary, these scientists present for the first time a successful experimental approach to study the effects of monosomy in human somatic cells.
A 3D printed vaccine patch offers vaccination without a shot
Scientists have created a 3D-printed vaccine patch that provides greater protection than a typical vaccine shot. The trick is applying the vaccine patch directly to the skin, which is full of immune cells that vaccines target.
The resulting immune response from the vaccine patch was 10 times greater than vaccine delivered into an arm muscle with a needle jab, according to a study conducted in animals and published by the team of scientists in the Proceedings of the National Academy of Sciences.
Considered a breakthrough are the 3D-printed microneedles lined up on a polymer patch and barely long enough to reach the skin to deliver vaccine. The ease and effectiveness of a vaccine patch sets the course for a new way to deliver vaccines that's painless, less invasive than a shot with a needle and can be self-administered.
Study results show the vaccine patch generated a significant T-cell and antigen-specific antibody response that was 50 times greater than a subcutaneous injection delivered under the skin.
That heightened immune response could lead to dose sparing, with a microneedle vaccine patch using a smaller dose to generate a similar immune response as a vaccine delivered with a needle and syringe.
“Transdermal vaccination via 3D-printed microneedles induces potent humoral and cellular immunity” by Cassie Caudill, Jillian L. Perry, Kimon Iliadis, Addis T. Tessema, Brian J. Lee, Beverly S. Mecham, Shaomin Tian and Joseph M. DeSimone, 22 September 2021, Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2102595118
Melting of polar ice shifting Earth itself, not just sea levels
The melting of polar ice is not only shifting the levels of our oceans, it is changing the planet Earth itself. Researchers recently explained in a paper in Geophysical Research Letters that, as glacial ice from Greenland, Antarctica, and the Arctic Islands melts, Earth's crust beneath these land masses warps, an impact that can be measured hundreds and perhaps thousands of miles away.
By analyzing satellite data on melt from 2003 to 2018 and studying changes in Earth's crust, researchers were able to measure the shifting of the crust horizontally. Their research, which was highlighted in Nature, found that in some places the crust was moving more horizontally than it was lifting. In addition to the surprising extent of its reach, the Nature brief pointed out, this research provides a potentially new way to monitor modern ice mass changes.
The implications of this movement are far-reaching. "Understanding all of the factors that cause movement of the crust is really important for a wide range of Earth science problems. For example, to accurately observe tectonic motions and earthquake activity, we need to be able to separate out this motion generated by modern-day ice-mass loss.
Sophie Coulson et al, The Global Fingerprint of Modern Ice‐Mass Loss on 3‐D Crustal Motion, Geophysical Research Letters (2021). DOI: 10.1029/2021GL095477
One more myth busted: Cavers find snakes but no genies in Yemen's 'Well of Hell'
A team of Omani cavers has made what is believed to be the first descent to the bottom of Yemen's fabled Well of Barhout—a natural wonder shunned by many locals, who believe it is a prison for genies.
The forbidding 'Well of Hell', whose dark, round aperture creates a 30-metre (100 foot) wide hole in the desert floor of Yemen's eastern province of Al-Mahra, plunges approximately 112 metres (367 feet) below the surface and, according to some accounts, gives off strange odours.
Inside, the Oman Cave Exploration Team (OCET) found snakes, dead animals and cave pearls—but no signs of the supernatural. https://phys.org/news/2021-09-cavers-snakes-genies-yemen-hell.html?...
Scientists report starch synthesis from carbon dioxide
Scientists recently reported a de novo route for artificial starch synthesis from carbon dioxide (CO2) for the first time.
The new route makes it possible to shift the mode ofstarchproduction from traditional agricultural planting toindustrial manufacturing, and opens up a new technical route for synthesizing complex molecules from CO2.
Starch is the major component of grain as well as an important industrial raw material. At present, it is mainly produced by crops such as maize by fixing CO2through photosynthesis. This process involves about 60 biochemical reactions as well as complex physiological regulation. The theoretical energy conversion efficiency of this process is only about 2%.
Strategies for the sustainable supply of starch and use of CO2are urgently needed to overcome major challenges of mankind, such as the food crisis and climate change. Designing novel routes other than plant photosynthesis for converting CO2to starch is an important and innovative S&T mission and will be a significant disruptive technology in today's world.
To address this issue, scientists at the Tianjin Institute of Industrial Biotechnology (TIB) of the Chinese Academy of Sciences (CAS) designed a chemoenzymatic system as well as an artificial starch anabolic route consisting of only 11 core reactions to convert CO2into starch.
This route was established by a "building block" strategy, in which the researchers integrated chemical and biological catalytic modules to utilize high-density energy and high-concentration CO2in a biotechnologically innovative way.
The researchers systematically optimized this hybrid system using spatial and temporal segregation by addressing issues such as substrate competition, product inhibition, and thermodynamical adaptation.
The artificial routecan produce starch from CO2with an efficiency 8.5-fold higher than starch biosynthesis in maize, suggesting a big step towards going beyond nature. It provides a new scientific basis for creating biological systems with unprecedented functions.
This work would open a window for industrial manufacturing of starch from CO2.
If the overall cost of the process can be reduced to a level economically comparable with agricultural planting in the future, it is expected to save more than 90% of cultivated land and freshwater resources. In addition, it would also help to avoid the negative environmental impact of using pesticides and fertilizers, improve human food security, facilitate a carbon-neutral bioeconomy, and eventually promote the formation of a sustainable bio-based society.
Cai Tao et al, Cell-free chemoenzymatic starch synthesis from carbon dioxide, Science (2021). DOI: 10.1126/science.abh4049
The Common Kitchen Ingredient That Could Help if Your Child Swallows a Battery
Every day, and thousands of times a year, a kid swallows a battery.
In the last 20 years or so, this dangerous and sometimes fatal accident has actually becomesignificantly more commonin children, and severe injuries caused bybutton battery ingestion(BBI) have led to a marked increase in hospitalizations.
Thankfully, in most such cases the item ends up passing harmlessly through the patient's digestive tract. However, even tiny batteries can cause tremendous damage if they get stuck in the esophagus.
Young children up to six years of age are most at risk of BBI complications due to their smaller body size, which increases the chance that a swallowed battery might get lodged in their esophagus – especially larger button batteries such as the ubiquitous20-millimeter CR2032, used in a vast range of small electronics.
Within just two hours, a stuck battery can cause severe burns as its negatively charged surface makes prolonged contact with the conductive tissue of the esophagus; this contactproduces an electrical currentand breaks nearby water down into a highly corrosive fluid.
If this happens to your child – or you suspect your young, non-verbal child might have swallowed a battery – do not delay.Seek immediate medical attention, as a lodged battery could require urgent endoscopic removal.
However, while you're waiting for medical assistance, researchers now say there is something you can do yourself to mitigate the risk of tissue injury – and it makes use of a condiment many of us have in our kitchens.
According to anewly published research summaryon BBI events and complications, honey may help when administered before the patient reaches the hospital, given at 10 milliliters every 10 minutes for children older than one year (up to six doses).
That recommendation is based on a study published in 2018, which explored injury mitigation from button battery blockages in the esophagus using an animal model of young pigs.
In the experiment, researchers tested a range of different household liquids (including honey, maple syrup, Gatorade, and fruit juices) to see whether any of them helped minimize tissue injury resulting from battery lodgment in the animal's esophagus.
Ultimately, two liquids produced the most clinically optimal results: honey, and a product called Carafate, (brand-name version of the medication sucralfate), which is used to treat ulcers and other stomach conditions.
"In the crucial period between button battery ingestion and endoscopic removal, early and frequent ingestion of honey in the household setting and Carafate in the clinical setting has the potential to reduce injury severity and improve patient outcomes.
Aspirin and Birth Defects: Fetal Cell Inhibition—Science News, October 2, 1971
Although aspirin has triggered defects in rat and mice fetuses, the evidence suggesting aspirin taken by women during pregnancy can harm their offspring has been circumstantial at best. Now, however … [evidence shows] that aspirin can dramatically arrest the growth of human embryo cells.
Scientists are still sorting out how aspirin and other nonsteroidal anti-inflammatory drugs, collectively known as NSAIDs, affect pregnancy at every stage. Taking NSAIDs during the first trimester is known toincrease the risk of miscarriage. In 2020, the U.S. Food and Drug Administration warned that people who are 20 weeks or more into a pregnancy should avoid using NSAIDs altogether because the drugs can cause rare but serious kidney problems as well as heart problems for fetuses. However, exceptions can be made forpregnant people at risk of preeclampsia, clotting and preterm delivery. In such cases, the FDA recommends that doctors prescribe the lowest effective dose of aspirin.
Unbelievable DRONE display - Guinness World Records
The longest animation performed by unmanned aerial vehicles (UAVs) is 26 min 19 sec and was achieved by EFYI Group (China) and supported by Tianjin University (China) in Tianjin, China, on 18 December 2020. They depicted the life of Dutch artist Vincent Van Gogh.
Researchers reporting in ACS Nano have found a way to represent a protein’s structure as music.
A Self-Consistent Sonification Method to Translate Amino Acid Sequences into Musical Compositions and Application in Protein Design using Artificial Intelligence.
Mercury released into the atmosphere by industry enters the sea and from there makes its way into the food chain. Now, an analysis by researchers has revealed how the harmful substance enters seawater in the first place. This is not primarily via rainfall, as previously assumed, but rather also involves gas exchange. Measures to reduce mercury emissions could therefore take effect faster than previously thought.
Every year, 2,000 metric tons of gaseous mercury are released into the atmosphere by coal-fired power stations and mining activities. The harmful substancethen adopts various chemical forms as it circulates between the air, soil and water in a complex cycle. Mercury is particularly dangerous in the sea, where it accumulates in fish in the form of highly toxic methylmercury. When this compound enters the human body due to the consumption of fish, it can have an adverse effect on brain development in children and cause cardiovascular diseases in adults.
It's estimated that human activities have tripled the amount of mercury in the surface ocean since the onset of industrialization. Those are just assumptions, however, as there are no collector stations for precipitation over the sea.
The gap was closed by analyzing seawater samples using a new method that allows researchers to distinguish whether mercury originates from precipitation or entered the sea via gas exchange, . Known as "fingerprinting," this technique is based on the measurement of tiny weight differences between naturally occurring mercury atoms, known as isotopes.
The analyses revealed that—contrary to previous assumptions—only about half of the mercury in the sea originates from precipitation, while the other half enters the oceans due to the uptake of gaseous mercury.
Researchers suspect that mercury uptake by plants drives more of the heavy metal to be deposited on land, where it is safely sequestered in soils and poses less of a risk to humans.
The new findings are also important for the implementation of the Minamata Convention of 2013, whereby 133 countries committed to reducing mercury emissions: "If less mercury enters the sea via rainfall, a reduction in emissions could cause mercury levels in seawater to drop faster than anticipated."
Since May 2021, drivers crossing into Singapore at the Tuas Checkpoint have been required to breathe into a cigar-sized mouthpiece connected to a mass spectrometer. In less than a minute, the device analyzes the breath samples for COVID-19. According to a new feature article in Chemical & Engineering News, such breath-based diagnostics might be a fast, cheap way to detect infection, although challenges exist.
More than a year into the pandemic, PCR-based assays—which require samples to be collected from patients' nasal passages with a long cotton swab—remain the gold standard for COVID-19 diagnosis. However, such tests are uncomfortable, slow and relatively expensive.
That's why several companies have launched breathalyzer-like tests to detect SARS-CoV-2 infection. These tests rely on altered ratios of volatile organic compounds (VOCs) in exhaled breath, which reflect metabolic changes triggered by the virus. But questions about whether the technology is sufficiently sensitive and reproducible are still unanswered.
One challenge is that researchers haven't sufficiently defined the levels of VOCs in the breath of healthy people, which makes it difficult to accurately measure when someone's exhalation deviates from the norm. As a result, some breath-based tests have had disappointing results when used in real life. Also, some VOCs change similarly in response to different viruses or conditions, making it important to identify unique patterns or ratios of biomarkers that change only upon infection with SARS-CoV-2. Scientists in the field are hopeful that continued standardization and validation will eventually create a robust breath-based diagnostic that might even be able to detect infection earlier than PCR-based tests, before a person begins shedding the virus.
Toxic DNA buildup in eyes may drive blinding macular degeneration
Common HIV drugs could stop vision loss, research suggests
Damaging DNA builds up in the eyes of patients with geographic atrophy, an untreatable, poorly understood form of age-related macular degeneration that causes blindness, new research reveals. Based on the discovery, the researchers think it may be possible to treat the disease with common HIV drugs or an even safer alternative.
Geographic atrophy is an advanced form of age-related macular degeneration, a potentially blinding disease estimated to affect 200 million people around the world. The disease ultimately destroys vital cells in the retina, the light-sensing portion of the eye
A harmful DNA, known as Alu cDNA, was previously discovered to be manufactured in the cytoplasm. The new findings offer insights into how geographic atrophy progresses over time. This finding in human eyes that the levels of toxic Alu cDNA are highest at the leading edge of the geographic atrophy lesion provides strong evidence that it is responsible for this expansion over time that leads to vision loss.
As Alu DNA accumulates in the eye, it triggers harmful inflammation via a part of the immune system called the inflammasome. The researchers identified how this happens, discovering a previously unknown structural facet of Alu that triggers the immune mechanism that leads to the death of the vital retinal cells.
That's where HIV drugs called nucleoside reverse transcriptase inhibitors, or NRTIs, could come in. The researchers' new work in lab mice suggests these drugs, or safer derivatives known as Kamuvudines, could block the harmful inflammation and protect against retinal cell death.
Alu complementary DNA is enriched in atrophic macular degeneration and triggers retinal pigmented epithelium toxicity via cytosolic innate immunity. Science Advances, 2021; 7 (40) DOI: 10.1126/sciadv.abj3658
Study unveils the quantum nature of the interaction between photons and free electrons
For several decades, physicists have known that light can be described simultaneously as a wave and a particle. This fascinating 'duality' of light is due to the classical and quantum nature of electromagnetic excitations, the processes through which electromagnetic fields are produced.
So far, in all experiments in which light interacts with free electrons, it has been described as a wave. Researchers at Technion—Israel Institute of Technology, however, have recently gathered the first experimental evidence revealing the quantum nature of the interaction between photons and free electrons. Their findings, published in Science, could have important implications for future research investigating photons and their interaction with free electrons.
Raphael Dahan et al, Imprinting the quantum statistics of photons on free electrons, Science (2021). DOI: 10.1126/science.abj7128
Ofer Kfir, Entanglements of Electrons and Cavity Photons in the Strong-Coupling Regime,Physical Review Letters(2019).DOI: 10.1103/PhysRevLett.123.103602
Valerio Di Giulio et al, Probing quantum optical excitations with fast electrons,Optica(2019).DOI: 10.1364/OPTICA.6.001524
Understanding how the human brain produces complex thought is daunting given its intricacy and scale. The brain contains approximately 100 billion neurons that coordinate activity through 100 trillion connections, and those connections are organized into networks that are often similar from one person to the next. A Dartmouth study has found a new way to look at brain networks using the mathematical notion of fractals, to convey communication patterns between different brain regions as people listened to a short story. The results are published in Nature Communications.
To generate our thoughts, our brains create amazing lightning storm of connection patterns. The patterns look beautiful, but they are also incredibly complicated. Our mathematical framework lets us quantify how those patterns relate at different scales, and how they change over time.
In the field of geometry, fractals are shapes that appear similar at different scales. Within a fractal, shapes and patterns are repeated in an infinite cascade, such as spirals comprised of smaller spirals that are in turn comprised of still-smaller spirals, and so on. Dartmouth's study shows thatbrainnetworks organize in a similar way: patterns of brain interactions are mirrored simultaneously at different scales. When people engage in complex thoughts, their networks seem to spontaneously organize into fractal-like patterns. When those thoughts are disrupted, thefractal patternsbecome scrambled and lose their integrity.
The researchers developed a mathematical framework that identifies similarities innetworkinteractions at different scales or "orders." When brain structures do not exhibit any consistent patterns of interaction, the team referred to this as a "zero-order" pattern. When individual pairs of brain structures interact, this is called a "first-order" pattern. "Second-order" patterns refer to similar patterns of interactions in different sets of brain structures, at different scales. When patterns of interaction become fractal— "first-order" or higher— the order denotes the number of times the patterns are repeated at different scales.
The study shows that when people listened to an audio recording of a 10-minute story, their brain networks spontaneously organized into fourth-order network patterns. However, this organization was disrupted when people listened to altered versions of the recording. For instance, when the story's paragraphs were randomly shuffled, preserving some but not all of the story's meaning, people's brain networks displayed only second-order patterns. When every word of the story was shuffled, this disrupted all but the lowest level (zero-order) patterns.
The more finely the story was shuffled, the more the fractal structures of the network patterns were disrupted.
Since the disruptions in those fractal patterns seemed directly linked with how well people could make sense of the story, this finding may provide clues about how our brain structures work together to understand what is happening in the narrative."
The fractal network patterns were surprisingly similar across people: patterns from one group could be used to accurately estimate what part of the story another group was listening to.
The team also studied which brain structures were interacting to produce thesefractalpatterns. The results show that the smallest scale (first-order) interactions occurred in brain regions that process raw sounds. Second-order interactions linked these raw sounds with speech processing regions, and third-order interactions linked sound and speech areas with a network of visual processing regions. The largest-scale (fourth-order) interactions linked these auditory and visual sensory networks with brain structures that support high-level thinking. According to the researchers, when these networks organize at multiple scales, this may show how the brain processes raw sensory information into complex thought—from raw sounds, to speech, to visualization, to full-on understanding.
The researchers' computational framework can also be applied to areas beyond neuroscience and the team has already begun using an analogous approach to explore interactions in stock prices and animal migration patterns.
High-level cognition during story listening is reflected in high-order dynamic correlations in neural activity patterns, Nature Communications (2021). DOI: 10.1038/s41467-021-25876-x
Warming ocean waters have caused a drop in the brightness of the Earth, according to a new study.
Researchers used decades of measurements of earthshine—the light reflected from Earth that illuminates the surface of the Moon—as well as satellite measurements to find that there has been a significant drop in Earth's reflectance, oralbedo, over the past two decades.
The Earth is now reflecting about half a watt less light per square meter than it was 20 years ago, with most of the drop occurring in the last three years of earthshine data, according to the new study in the AGU journalGeophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.
That's the equivalent of 0.5% decrease in the Earth's reflectance. Earth reflects about 30% of the sunlight that shines on it.
Two things affect the net sunlight reaching the Earth: the Sun's brightness and the planet's reflectivity. The changes in Earth's albedo observed by the researchers did not correlate with periodic changes in the Sun's brightness, so that means changes in Earth's reflectiveness are caused by something on the Earth.
Specifically, there has been a reduction of bright, reflective low-lying clouds over the eastern Pacific Ocean in the most recent years, according to satellite measurements made as part of NASA's Clouds and the Earth's Radiant Energy System (CERES) project.
That's the same area, off the west coasts of North and South America, where increases in sea surface temperatureshave been recorded because of the reversal of a climatic condition called the Pacific Decadal Oscillation, with likely connections to global climate change.
The dimming of the Earth can also be seen in terms of how much more solar energyis being captured by Earth's climate system. Once this significant additional solar energy is in Earth's atmosphere and oceans, it may contribute to global warming , as the extra sunlight is of the same magnitude as the total anthropogenic climate forcing over the last two decades.
P. R. Goode et al, Earth's Albedo 1998–2017 as Measured From Earthshine, Geophysical Research Letters (2021). DOI: 10.1029/2021GL094888
'Fight or flight' – unless internal clocks are disrupted, study in mice shows
For humans and animals, many aspects of normal behavior and physiology rely on the proper functioning of the body's circadian clocks.
Here's how it's supposed to work: Yourbrainsends signals to your body to release different hormones at certain times of the day. For example, you get a boost of thehormonecortisol—nature's built-in alarm system—right before you usually wake up.
But hormone release actually relies on the interconnected activity of clocks in more than one part of the brain. New research from Washington University in St. Louis shows how daily release of glucocorticoids depends on coordinated clock-gene and neuronal activity rhythms in neurons found in two parts of the hypothalamus, thesuprachiasmatic nucleus(SCN) and paraventricular nucleus (PVN).
The new study, conducted with freely behaving mice, is published Oct. 1 inNature Communications.
Normal behavior and physiology depends on a near 24-hour circadian release of various hormones. When hormone release is disrupted, it can lead to numerous pathologies, including affective disorders like anxiety and depression and metabolic disorders like diabetes and obesity.
The daily timing of hormone release is controlled by the SCN. Located in the hypothalamus, just above where the optic nerves cross, neurons in the SCN send daily signals that are decoded in other parts of the brain that talk to the adrenal glands and the body's endocrine system.
"Cortisol in humans (corticosterone in mice) is more typically known as a stress hormone involved in the 'fight or flight' response. But the stress of waking up and preparing for the day is one of the biggest regular stressors to the body. Having a huge amount of this glucocorticoid released right as you wake up seems to help you gear up for the day.
Circadian neurons in the paraventricular nucleus entrain and sustain daily rhythms in glucocorticoids, Nature Communications (2021). DOI: 10.1038/s41467-021-25959-9
A breathing tube through the butt could be an alternative to mechanical ventilators
Inspired by animals that breathe through their butts, scientists show that mammals can also harness the incredible breathing ability of our butts.
To survive in extreme low-oxygen conditions deep in the ocean, fish and other creatures have developed remarkable adaptations. For example, sea spiders, loaches, and catfishevolved the ability to breathe through their butts. And they might not be the only butt breathers out there.
A recentstudyin the journal Mednow suggests that mammals, humans included, may be able to breathe through their rear ends as well. Mice, rats, and pigs could all stave off the devastating effects of oxygen deprivation if given an oxygen enema. But could this new method provide temporary oxygen while a patient awaits a ventilator?
While we often consider the butt as the exit for waste in our body, it is also an entryway with lifesaving potential. After all, humans and plenty of other mammals can absorb medications rectally. That’s because there’s a lot ofblood vesselsin the area, allowing medicine easy entry.
But medicine is specially designed to maximize absorption in the body. Oxygen doesn’t have nearly as easy a path towards entry into the bloodstream through the rectum because of the mucus membrane mammals have on the intestines. There are also important anatomical differences between our intestines and those of fish that already harness this ability. Animals that can breathe through their butts, likeloaches, had a much thinner epithelium in their guts and a lot less mucus. During the course of early development, a butt-breathing genetic pathway is turned on that helps dictate the structure of the intestine. When it’s all said and done, the posterior end of the intestine is equipped with all the structures necessary for respiration (and gas exchange).
Would this mucus prevent oxygenation in mice? In the first experiment, researchers used a model of oxygen deprivation in mice, preventing them from breathing through their lungs. The control group didn’t receive any intestinal ventilation, one group received oxygen through an anal catheter, and the final group had the mucus layer on their intestines “scrubbed” before receiving anal ventilation.
Remarkably, the mice supplied oxygen through their anus had elevated oxygen levels in their blood. The final group that also had their intestinal mucus scrubbed fared even better, surviving the longest in the low-oxygen conditions — five times as long as the control group. This experiment proved that there is potential for mammals to breathe through their butt, however, the mucus layer covering the intestinal epithelial cells makes it more difficult.
In a clinical setting, scrubbing the mucus off of a person’s intestines isn’t really feasible, and doesn’t sound like a pleasant experience. But using a method akin to an enema may work, by infusing safe, oxygenated liquid through the butt. This liquid, called perfluorodecalin, could safely store and deliver oxygen via an enema. Due to the properties of this liquid, it doesn’t need to scrub the mucus off of the intestines, meaning less discomfort and abrasion. Oxygen diffuses into the bloodstream while carbon dioxide diffuses out. Since it holds a lot of oxygen and carbon dioxide very easily, it is alsodelivered safely to the lungs, and is already in clinical use.
During COVID-19, many hospitals find themselves short on ventilators. During the pandemic, many will require the use of a ventilator for an average of 15 days, while a few people will need significantly more time. Ventilators aren’t something that a person can use for one day and then get discharged. The first wave of people requiring ventilators will receive them immediately. However, someone whose lungs fail the next day may need to survive for two weeks without one.
Dr. Krishna Kumari Challa
Mass extinction: A warning that this can happen now too
The end-Permian mass extinction event of roughly 252 million years ago—the worst such event in earth's history—has been linked to vast volcanic emissions of greenhouse gases, a major temperature increase, and the loss of almost every species in the oceans and on land.
Now, it seems that even the lakes and rivers were no safe havens. A recent study published by an international team of researchers has identified a new cause of extinction during extreme warming events: toxic microbial blooms.
In a healthy ecosystem, microscopic algae and cyanobacteria provide oxygen to aquatic animals as a waste product of their photosynthesis. But when their numbers get out of control, these microbes deplete free oxygen, and even release toxins into the water. By studying the fossil, sediment, and chemical records of rocks near Sydney, Australia, the researchers discovered that several pulses of bloom events had occurred soon after the first volcanic rumblings of the end-Permian mass extinction. Once the bottom-feeder animals, or "detritivores," were killed off, there was no one left to keep the microbes in check. The fresh water systems then seethed with algae and bacteria, delaying the recovery of animals for perhaps millions of years.
We're seeing more and more toxic algae blooms in lakes and in shallow marine environments that's related to increases in temperature and changes in plant communities which are leading to increases in nutrient contributions to freshwater environments. So, a lot of parallels to today. The volcanism was a source of CO2 in the past but we know that the rate of CO2 input that was seen back then was similar to the rate of CO2 increases we're seeing today because of anthropogenic effects.
We can get a sense of how much climate has changed in the past, what the extremes are, how fast it can change, what the causes of climate change are and that gives us a nice backdrop for understanding what's happening today. The end-Permian is one of the best places to look for parallels with what's happening now.
The other big parallel is that the increase in temperature at the end of the Permian coincided with massive increases in forest fires. One of the things that that destroyed whole ecosystems was fire, and we're seeing that right now in several places .
We should be concerned like hell!
Chris Mays et al, Lethal microbial blooms delayed freshwater ecosystem recovery following the end-Permian extinction, Nature Communications (2021). DOI: 10.1038/s41467-021-25711-3
https://phys.org/news/2021-09-animals-died-toxic-soup-earth.html?ut...
Sep 18, 2021
Dr. Krishna Kumari Challa
Do the northern lights make sounds that you can hear?
https://theconversation.com/do-the-northern-lights-make-sounds-that...
Sep 18, 2021
Dr. Krishna Kumari Challa
Antibodies from original strain COVID-19 infection don't bind to variants, study finds
People infected with the original strain of the virus that causes COVID-19 early in the pandemic produced a consistent antibody response, making two main groups of antibodies to bind to the spike protein on the virus’s outer surface. However, those antibodies don’t bind well to newer variants, a new study found.
Researchers found that many antibody sequences converged into two main groups, indicating a consistent human immune response to the virus. The researchers studied the convergent antibodies’ ability to bind to several variants and found that they no longer bound to some. The finding has implications for the ability of new variants to reinfect people who contracted earlier versions of the virus, as well as for the continuing efficacy of vaccines and the design of possible vaccine boosters.
Even though this antibody response is very common with the original strain, it doesn’t really interact with variants. That, of course, raises the concern of the virus evolving to escape the body’s main antibody response. Some antibodies should still be effective – the body makes antibodies to many parts of the virus, not only the spike protein – but the particular groups of antibodies that we saw in this study will not be as effective.
The researchers said they would like to conduct similar studies characterizing antibody responses to delta and other variants, to see whether they also produce a convergent response and how it differs from the original strain.
It is expected that the antibody response to those variants would be quite different.
https://www.nature.com/articles/s41467-021-24123-7'
https://news.illinois.edu/view/6367/1126344363
https://researchnews.cc/news/8965/Antibodies-from-original-strain-C...
Sep 19, 2021
Dr. Krishna Kumari Challa
Will Indian researchers lose free access to scientific papers?
It’ll depend on the outcome of an ongoing case against SciHub and LibGen websites in the Delhi High Court.
On December 21, 2020, academic publishers Elsevier Ltd, Wily Pvt Ltd, and the American Chemical Society sued websites SciHub and Library Genesis, also known as LibGen, for copyright infringement in the Delhi High Court, demanding that ISP providers permanently block them in India.
These websites are a primary source for researchers in India, making available for free thousands of otherwise paywalled research papers. Because, as SciHub notes, “Research should be free to read.” Having intellectual property restrictions in research throttle access to and flow of knowledge while science can only progress when it’s widely read and debated.
Elsevier owns over 2,600 journals, including the Lancet, and all of them are paywalled with subscription rates going up to thousands of dollars, making the latest knowledge hard to access for researchers.
Sep 19, 2021
Dr. Krishna Kumari Challa
The Future of Wearable Tech
Sep 20, 2021
Dr. Krishna Kumari Challa
Engineers create light-emitting plants that can be charged repeatedly
Using specialized nanoparticles embedded in plant leaves, MIT engineers have created a light-emitting plant that can be charged by an LED. After 10 seconds of charging, plants glow brightly for several minutes, and they can be recharged repeatedly.
These plants can produce light that is 10 times brighter than the first generation of glowing plants that the research group reported in 2017.
Creating ambient light with the renewable chemical energy of living plants is a bold idea. It represents a fundamental shift in how we think about living plants and electrical energy for lighting.
The particles can also boost the light production of any other type of light-emitting plant, including those the researchers originally developed. Those plants use nanoparticles containing the enzyme luciferase, which is found in fireflies, to produce light. The ability to mix and match functional nanoparticles inserted into a living plant to produce new functional properties is an example of the emerging field of "plant nanobionics."
Their first generation of light-emitting plants contained nanoparticles that carry luciferase and luciferin, which work together to give fireflies their glow. Using these particles, the researchers generated watercress plants that could emit dim light, about one-thousandth the amount needed to read by, for a few hours.
In the new study, Strano and his colleagues wanted to create components that could extend the duration of the light and make it brighter. They came up with the idea of using a capacitor, which is a part of an electrical circuit that can store electricity and release it when needed. In the case of glowing plants, a light capacitor can be used to store light in the form of photons, then gradually release it over time.
To create their "light capacitor," the researchers decided to use a type of material known as a phosphor. These materials can absorb either visible or ultraviolet light and then slowly release it as a phosphorescent glow. The researchers used a compound called strontium aluminate, which can be formed into nanoparticles, as their phosphor. Before embedding them in plants, the researchers coated the particles in silica, which protects the plant from damage.
The particles, which are several hundred nanometers in diameter, can be infused into the plants through the stomata—small pores located on the surfaces of leaves. The particles accumulate in a spongy layer called the mesophyll, where they form a thin film. A major conclusion of the new study is that the mesophyll of a living plant can be made to display these photonic particles without hurting the plant or sacrificing lighting properties, the researchers say.
This film can absorb photons either from sunlight or an LED. The researchers showed that after 10 seconds of blue LED exposure, their plants could emit light for about an hour. The light was brightest for the first five minutes and then gradually diminished. The plants can be continually recharged for at least two weeks.
Pavlo Gordiichuk et al, Augmenting the living plant mesophyll into a photonic capacitor, Science Advances (2021). DOI: 10.1126/sciadv.abe9733
https://phys.org/news/2021-09-light-emitting-repeatedly.html?utm_so...
Sep 21, 2021
Dr. Krishna Kumari Challa
Nano-scale discovery could help to cool down overheating in electronics
A team of physicists solved the mystery behind a perplexing phenomenon in the nano realm: why some ultra-small heat sources cool down faster if you pack them closer together. The findings could one day help the tech industry design faster electronic devices that overheat less.
Often, heat is a challenging consideration in designing electronics. You build a device then discover that it's heating up faster than desired.
In 2015, physicists were experimenting with bars of metal that were many times thinner than the width of a human hair on a silicon base. When they heated those bars up with a laser, something strange occurred.
They behaved very counterintuitively. These nano-scale heat sources do not usually dissipate heat efficiently. But if you pack them close together, they cool down much more quickly.
Now, the researchers know why it happens.
In the new study, they used computer-based simulations to track the passage of heat from their nano-sized bars. They discovered that when they placed the heat sources close together, the vibrations of energy they produced began to bounce off each other, scattering heat away and cooling the bars down.
The group's results highlight a major challenge in designing the next generation of tiny devices, such as microprocessors or quantum computer chips: When you shrink down to very small scales, heat does not always behave the way you think it should.
Directional thermal channeling: A phenomenon triggered by tight packing of heat sources, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2109056118
https://phys.org/news/2021-09-nano-scale-discovery-cool-overheating...
Sep 21, 2021
Dr. Krishna Kumari Challa
Yeast and bacteria together biosynthesize plant hormones for weed control
Plants regulate their growth and development using hormones, including a group called strigolactones that prevent excessive budding and branching. For the first time, scientists have synthesized strigolactones from microbes.
Strigolactones also help plant roots form symbiotic relationships with microorganisms that allow the plant to absorb nutrients from the soil. These two factors have led to agricultural interest in using strigolactones to control the growth of weeds and root parasites, as well as improving nutrient uptake.
These root-extruding compounds don't come without risks. They also stimulate germination of witchweeds and broomrapes, which can cause entire crops of grain to fail, making thorough research essential prior to commercial development. Scientists are still learning about the physiological roles played by this diverse group of hormones in plants. Until recently, manufacturing pure strigolactones for scientific study has been difficult and too costly for agricultural use.
The new work provides a unique platform to investigate strigolactone biosynthesis and evolution, and it lays the foundation for developing strigolactone microbial bioproduction processes as alternative sourcing.
Researchers directed a group that inserted plant genes associated with strigolactone production into ordinary baker's yeast and nonpathogenic Escherichia coli bacteria that together produced a range of strigolactones.
Sheng Wu et al, Establishment of strigolactone-producing bacterium-yeast consortium, Science Advances (2021). DOI: 10.1126/sciadv.abh4048
https://phys.org/news/2021-09-yeast-bacteria-biosynthesize-hormones...
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Sep 21, 2021
Dr. Krishna Kumari Challa
Science of Concrete & the Surfside Condo Collapse
Sep 21, 2021
Dr. Krishna Kumari Challa
The Placebo Effect Is an Amazing Illusion, But That Doesn't Mean It's Medicine
Placebo is a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment.
The placebo is one of science's greatest mysteries. The pill that isn't a pill. The medical illusion that somehow becomes real.
The mind-boggling weirdness of the placebo effect is certainly a strange thing, nobody doubts that.
But just because the placebo effect occasionally delivers unexpected outcomes doesn't mean we should overestimate how powerful it is – nor try to find a place for it in the medical care of patients, scientists are now warning.
In a new perspective article, researchers argue that recent suggestions placebos could play a role in clinical care are unfounded, and are based on flawed evidence.
Much of the current discourse on placebo seems to focus more on enshrining placebos as mysterious and highly effective and less on making a practical difference to patient care and outcomes.
Observations of the placebo effect can be traced back to the 18th century, and the reputation of the placebo has grown ever since: the idea that an inert, sham treatment, taken unknowingly by a patient, can sometimes deliver therapeutic effects like the real thing.
That reputation is mostly underserved. A Cochrane review of placebos considered 234 trials and concluded that, in general, placebos do not produce major health benefits, except for some small and inconsistent effects on self-reported outcomes such as pain or nausea," the researchers explain.
Placebos remain important for clinical trials because they help achieve blinding and, thus, control of bias," the team writes.
"When administered in a blinded fashion, a placebo will provide a small effect, but the real treatment will normally provide better outcomes for the patient… It may be better to dismiss placebos and instead manage patients with evidence-based treatments., they conclude.
https://onlinelibrary.wiley.com/doi/10.5694/mja2.51230
https://www.sciencealert.com/the-placebo-effect-is-an-amazing-illus...
Sep 21, 2021
Dr. Krishna Kumari Challa
Serious Infections Linked to Autism: Study
In both a mouse model and the hospital records of more than 3 million children, researchers found a connection between strong immune activation in males and later symptoms of autism spectrum disorder.
While researchers have found plenty of gene variants that seem to increase the risk of an autism diagnosis, it’s not clear why some people carrying these mutations develop autism spectrum disorders and some do not. In a study published today (September 17) in Science Advances, researchers point to a potential answer: severe infections during early childhood. After an early immune challenge, male mice with a mutated copy of the tuberous sclerosis complex 2 (Tsc2) gene developed deficits in social behavior linked to changes in microglia, the immune cells of the brain. And an analysis of the hospital records of more than 3 million children showed that children, particularly boys, who were hospitalized for infections between ages 18 months and four years were more likely that healthy peers to receive a future autism spectrum disorder (ASD) diagnosis.
https://www.science.org/doi/10.1126/sciadv.abf2073
https://www.the-scientist.com/news-opinion/serious-infections-linke...
Sep 21, 2021
Dr. Krishna Kumari Challa
Inhibiting targets of SARS-CoV-2 proteases can block infection, study shows
Researchers have shown how SARS-CoV-2 viral proteases attack the host cell, and how this can be targeted to stop virus replication in cell culture using existing drugs.
The new findings, published today in Nature Communications, offer a powerful resource to understand proteolysis in the context of viral infection, and to inform the development of targeted strategies to inhibit the virus that causes COVID-19.
Both viral and cellular proteases play a crucial role in SARS-CoV-2 replication, and inhibitors targeting proteases have already shown success at inhibiting SARS-CoV-2 in cell culture models.
In this study, researchers used a mass spectrometry approach to study proteolytic cleavage events during SARS-CoV-2 infection.
The team found previously unknown cleavage sites in multiple viral proteins, including major antigenic proteins S and N, which are the main targets for vaccine and antibody testing efforts.
They discovered significant increases in cellular cleavage events consistent with cleavage by SARS-CoV-2 main protease (Mpro) and identified 14 potential high-confidence substrates of the main and papain-like proteases, validating a subset with in vitro assays.
They went on to show that siRNA depletion of these cellular proteins inhibits SARS-CoV-2 replication, and that drugs targeting two of these proteins: the tyrosine kinase SRC and Ser/Thr kinase MYLK, showed a dose-dependent reduction in SARS CoV-2 titres.
Both Bafetinib (an experimental cancer drug) and Sorafenib (an approved drug used to treat kidney and liver cancer) showed SARS-CoV-2 inhibition at concentrations that did not result in cytotoxicity in a human cell line model of infection.
Characterising proteolysis during SARS-CoV-2 infection identifies viral cleavage sites and cellular targets with therapeutic potential, Nature Communications (2021). DOI: 10.1038/s41467-021-25796-w
https://phys.org/news/2021-09-inhibiting-sars-cov-proteases-block-i...
Sep 22, 2021
Dr. Krishna Kumari Challa
Rock shape should be given greater consideration in rockfall risk assessments
The shape of rocks is a key factor in assessing rockfall hazard. This is the conclusion of a new study from the Institute for Snow and Avalanche Research.
Rockfall is a very real threat in an Alpine country like Switzerland. In order to assess the hazard at a given location and plan protective measures, engineering firms use computer models to calculate how far falling rocks can roll. However, the models are not yet able to adequately take into account the extent to which the mass, size or shape of a rock influences its movement. This would require real-world measurement data to be fed into the models, but until now such data were only available sporadically, since no systematic rockfall studies had been conducted.
First comprehensive experiments
That has now changed after researchers spent over four years carrying out rockfall experiments. This has allowed them to compile the largest set of measurement data to date.
The researchers used artificial rocks in the form of concrete blocks fitted with sensors, which they rolled down a slope near the Flüela Pass in the Swiss canton of Grisons. They compared different shapes and masses, reconstructed the complete trajectories and determined speeds, jump heights and runout zones (see info box). They have just published their results in the scientific journal Nature Communications.
The most significant finding is that the direction a rock rolls in depends much more on its shape than on its mass. While cube-shaped boulders plunge straight down the line of greatest slope, wheel-shaped rocks often pull away to one side and so may threaten a much wider area at the base of the slope. "This needs to be taken into consideration when assessing danger zones, but also when determining the location and dimensions of rockfall nets.
Because wheel-like rocks hit rockfall nets with their narrow side, their energy is concentrated on a much smaller area than is the case with cube-like rocks—so protective nets need to be stronger.
The data set is also available on the EnviDat platform, where it is freely accessible to other research groups. They can use it to calibrate their own algorithms or to develop new, more accurate models providing enhanced protection against rockfall.
Andrin Caviezel et al, The relevance of rock shape over mass—implications for rockfall hazard assessments, Nature Communications (2021). DOI: 10.1038/s41467-021-25794-y
https://phys.org/news/2021-09-greater-consideration-rockfall.html?u...
Sep 22, 2021
Dr. Krishna Kumari Challa
Satellite swarms may outshine the night sky’s natural constellations
“Mega-constellations” from those satellites will be visible to the naked eye, simulations suggest
A few years back somebody asked me from the art field, "If You 're asked to make a science-art installation, what would it be?" My instant answer was, "Groups of satellites in the night sky that shine like star constellations and also help the mankind".
"Wow!" was that person's reaction.
But, now that reply of mine is going to be revisited. Why? Companies like SpaceX and Amazon have launched hundreds of satellites into low orbits since 2019, with plans to launch thousands more in the works — a trend that’s alarming astronomers. The goal of these satellite “mega-constellations” is to bring high-speed internet around the globe, but these bright objects threaten to disrupt astronomers’ ability to observe the cosmos.
Now, a new simulation of the potential positions and brightness of these satellites shows that, contrary to earlier predictions, casual sky watchers will have their view disrupted, too. And parts of the world will be affected more than others.
Flat, smooth surfaces on satellites can reflect sunlight depending on their position in the sky. Earlier research had suggested that most of the new satellites would not be visible with the naked eye.
There are currently about 7,890 objects in Earth orbit, about half of which are operational satellites, according to the U.N. Office for Outer Space Affairs. But that number is increasing fast as companies launch more and more satellites . In August 2020, there were only about 2,890 operational satellites.
Part1
Sep 22, 2021
Dr. Krishna Kumari Challa
the researchers computed how many satellites will be in the sky at different times of year, at different hours of the night and from different positions on Earth’s surface. They also estimated how bright the satellites were likely to be at different hours of the day and times of the year.
The simulations showed that “the way the night sky is going to change will not affect all places equally,” Lawler says. The places where naked-eye stargazing will be most affected are at latitudes 50° N and 50° S, regions that cross lower Canada, much of Europe, Kazakhstan and Mongolia, and the southern tips of Chile and Argentina, the researchers found.
The geometry of sunlight in the summer means there will be hundreds of visible satellites all night long. It’s bad everywhere, but it’s worse there.
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A few visible satellites can be a fun spectacle. Astronomers have been meeting with representatives from private companies, as well as space lawyers and government officials, to work out compromises and mitigation strategies. Companies have been testing ways to reduce reflectivity, like shading the satellites with a “visor.” Other proposed strategies include limiting the satellites to lower orbits, where they move faster across the sky and leave a fainter streak in telescope images. Counterintuitively, lower satellites may be better for some astronomy research. “They move out of the way quick.”
But that lower altitude strategy will mean more visible satellites for other parts of the world, and more that are visible to the naked eye.
There are some latitudes on Earth where no matter what altitude you put your satellites at, they’re going to be all over the darn place. The only way out of this is fewer satellites.
There are currently no regulations concerning how bright a satellite can be or how many satellites a private company can launch. Scientists are grateful that companies are willing to work with them, but think that their cooperation is voluntary. Efforts are under way to bring the issue to the attention of the United Nations and to try to use existing environmental regulations to place limits on satellite launches.
S. Lawler, A. Boley and H. Rein. Visibility predictions for near-future satellite megaconstellations.... arXiv:2109.04328. Posted September 9, 2021.
https://www.sciencenews.org/article/satellite-mega-constellations-n...
Sep 22, 2021
Dr. Krishna Kumari Challa
Salty Diet Helps Gut Bugs Fight Cancer in Mice: Study
A high-salt diet suppressed the growth of tumors in a mouse model of melanoma, apparently because of an interplay between the gut microbiome and natural killer cells.
Salt may not be good for your BP, but .....
In mice, a diet high in salt suppresses tumor growth—but only when gut microbes are there to stimulate immune cells, a September 10 study in Science Advances reports. The findings raise tantalizing questions about the role of diet and gut microbes in human cancers, and may point to new avenues for therapeutic development.
While the study isn’t the first to connect a high-salt diet to shrinking tumors, the authors have shown a unique mechanistic role of high salt induced gut microbiome changes as the central phenomenon behind their observed anti-cancer effect.
The researchers pursued this line of inquiry because previous research had linked high salt intake with autoimmune diseases, suggesting that increased salt stimulates immune cells. Meanwhile, tumors are well known to grow in immune-suppressive environments. So they thought, “If we put salt in the mice’s diet, maybe [the immune system in] the tumor environment becomes activated,” suppressing cancerous growth.
a 2019 Frontiers in Immunology study from a European team led by Hasselt University immunologist Markus Kleinewietfeld reported that high-salt diets inhibited tumor growth in mice. No researchers carried out similar experiments, implanting mice with B16F10 skin melanoma cells and then feeding the tumor transplant mice diets with different salt levels, they got similar results: tumors grew slower in mice who were fed a high-salt diet.
https://www.science.org/doi/10.1126/sciadv.abg5016
https://www.the-scientist.com/news-opinion/a-salty-diet-helps-gut-b...
Sep 22, 2021
Dr. Krishna Kumari Challa
Brain-Eating Amoeba
Sep 22, 2021
Dr. Krishna Kumari Challa
Infants have more microplastics in their feces than adults, study finds
Microplastics—tiny plastic pieces less than 5 mm in size—are everywhere, from indoor dust to food to bottled water. So it's not surprising that scientists have detected these particles in the feces of people and pets. Now, in a small pilot study, researchers reporting in ACS' Environmental Science & Technology Letters discovered that infants have higher amounts of one type of microplastic in their stool than adults. Health effects, if any, are uncertain.
Little is known about the magnitude of human exposure to microplastics or their health effects. Although microplastics were once thought to pass harmlessly through the gastrointestinal tract and exit the body, recent studies suggest that the tiniest pieces can cross cell membranes and enter the circulation. In cells and laboratory animals, microplastic exposure can cause cell death, inflammation and metabolic disorders.
The researchers used mass spectrometry to determine the concentrations of PET and PC microplastics in six infant and 10 adult feces samples collected from New York state, as well as in three samples of meconium (a newborn infant's first stool). All samples contained at least one type of microplastic. Although average levels of fecal PC microplastics were similar between adults and infants, infant stool contained, on average, more than 10 times higher PET concentrations than that of adults.
Infants could be exposed to higher levels of microplastics through their extensive use of products such as bottles, teethers and toys, the researchers say.
Occurrence of Polyethylene Terephthalate and Polycarbonate Microplastics in Infant and Adult Feces, Environmental Science & Technology Letters (2021). pubs.acs.org/doi/abs/10.1021/acs.estlett.1c00559
https://phys.org/news/2021-09-infants-microplastics-feces-adults.ht...
Sep 23, 2021
Dr. Krishna Kumari Challa
Global cancer risk from burning organic matter comes from unregulated chemicals
Whenever organic matter is burned, such as in a wildfire, a power plant, a car's exhaust, or in daily cooking, the combustion releases polycyclic aromatic hydrocarbons (PAHs)—a class of pollutants that is known to cause lung cancer.
There are more than 100 known types of PAH compounds emitted daily into the atmosphere. Regulators, however, have historically relied on measurements of a single compound, benzo(a)pyrene, to gauge a community's risk of developing cancer from PAH exposure. Now MIT scientists have found that benzo(a)pyrene may be a poor indicator of this type of cancer risk.
In a modeling study appearing today in the journal GeoHealth, the team reports that benzo(a)pyrene plays a small part—about 11 percent—in the global risk of developing PAH-associated cancer. Instead, 89 percent of that cancer risk comes from other PAH compounds, many of which are not directly regulated.
Interestingly, about 17 percent of PAH-associated cancer risk comes from "degradation products"—chemicals that are formed when emitted PAHs react in the atmosphere. Many of these degradation products can in fact be more toxic than the emitted PAH from which they formed.
Jamie M. Kelly et al, Global Cancer Risk from Unregulated Polycyclic Aromatic Hydrocarbons, GeoHealth (2021). DOI: 10.1029/2021GH000401
https://phys.org/news/2021-09-global-cancer-unregulated-chemicals.h...
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Sep 23, 2021
Dr. Krishna Kumari Challa
Flying cars
Sep 23, 2021
Dr. Krishna Kumari Challa
Hairdressers say people are having allergic reactions to hair dye due to COVID
Covid-19: New allergic reactions to hair dye reported
It's important to always get a patch test before using a beauty product
News that there is a link between COVID-19 and allergies to hair dye is being reported more and more. Over the past year, more and more hairdressers have noticed a worrying increase in customers suffering allergic reactions to hair dye after testing positive for COVID-19.
Hairdressers report customers developing rashes and burns after using hair dye, even if it's a product they've used before. Now, according to the BBC, the trade body that represents hairdressers and beauticians is warning professionals to carry out additional patch tests to avoid facing legal action. Patch tests require customers to sample the product on their skin 24-48 hours before their appointment to see how they react.
https://www.bbc.com/news/av/health-58651244
https://www.cosmopolitan.com/uk/body/health/a37703414/allergic-reac...
Sep 24, 2021
Dr. Krishna Kumari Challa
The Roman Space Telescope's Wide Field Instrument
Sep 24, 2021
Dr. Krishna Kumari Challa
Winged microchip is smallest-ever human-made flying structure
Inspired by the way trees like maples disperse their seeds using little more than a stiff breeze, researchers developed a range of tiny flying microchips, the smallest one hardly bigger than a grain of sand.This flying microchip or 'microflier' catches wind and spins like a helicopter towards the ground.
The microfliers can be packed with ultra-miniaturized technology, including sensors, power sources, antennas for wireless communication, and even embedded memory for data storage.
Sep 24, 2021
Dr. Krishna Kumari Challa
Reprogramming heart muscle cells to repair damage from heart attacks
A team of researchers has found that it is possible to reprogram heart muscle to repair damaged tissue. In their paper published in the journal Science, the group describes their approach to repairing damaged hearts in mice and how well it worked when tested.
There are two main kinds of heart attack. The first occurs when something prevents the heart from beating. The second occurs when blood flow is restricted to parts of the heart, preventing the muscle in that area from beating. The first kind is generally fatal unless the heart can be restarted very quickly. The second is generally less serious, but can leave permanent, debilitating scarring. In this new effort, the researchers have found a way to prevent such scarring—at least in mice.
The work built on prior research that showed that in the case of a baby experiencing heart damage in utero, the heart can repair itself because the cardiomyocyte cells are in a state that allows rejuvenation. This is not the case after birth or later in life, as the cardiomyocytes have no ability to regenerate. After several years of effort, the researchers discovered a way to get adult cardiomyocytes to revert back to fetal-like cardiomyocytes by reprogramming them using the Yamanaka factors c-Myc, Klf4, Sox2 and Oct4. Their research showed that such factors express for cell renewal. The reprogramming also featured an on/off switch using the antibiotic doxycycline.
The researchers then tested their approach by giving mice with reprogrammed cells doxycycline just prior to and after inducing heart damage. They found that under both scenarios, heart regeneration occurred along with heart function improvement. The researchers also tried giving similar test mice doxycycline six days after experiencing heart damage and found it had no impact. Thus, the window of repair is short. Further testing also showed that if doxycycline was administered for too long a period, cancerous tumors developed. Much more work is required to determine if a similar approach might work for humans, and if it can be done without increasing the risk of cancer.
Yanpu Chen et al, Reversible reprogramming of cardiomyocytes to a fetal state drives heart regeneration in mice, Science (2021). DOI: 10.1126/science.abg5159
https://medicalxpress.com/news/2021-09-reprogramming-heart-muscle-c...
Sep 25, 2021
Dr. Krishna Kumari Challa
Scientists suggest pregnant women only take paracetamol/acetaminophen only if medically necessary
A group of 13 scientists has penned a consensus statement regarding the use of paracetamol/acetaminophen (APAP) by pregnant women. In their paper, published in the journal Nature Reviews Endocrinology, the group suggests that pregnant women only take paracetamol/acetaminophen only if it is medically necessary. Nature has also published an Editorial in the same journal issue, outlining the consensus statement and noting that its authors are not calling for a ban on the drug being used, instead they are suggesting that it be taken more cautiously by pregnant women because of a possible risk of birth defects.
In their paper, the authors note that research over the past several years has shown that it is possible under some circumstances for APAP to alter fetal development which in some cases can lead to problems with neurological, urological and reproductive disorders in the baby—they looked at 29 studies and found evidence of birth defects in 26 of them. They call for more research to be conducted to better understand possible problems with the drug being used by pregnant women. They also acknowledge—as do several experts in a reaction piece published on the Science Media Centre, site—that APAP is the only drug currently available for pain management for pregnant women. And they point out that medical use of APAP is generally warranted when the mother experiences problems that can negatively impact her baby—such as having a fever. But they also note that use of APAP by pregnant women appears to have crept up into general use as it has gained a reputation as being safe to use as an all-purpose analgesic.
The authors of the consensus statement further suggest that their intent in publishing such an article is to bring renewed and more focused attention to the possibility of APAP use leading to certain birth defects and the conditions under which they might arise. They note that current research has shown, for example, that the possibility of harm seems to increase as the duration of APAP use goes up. Thus, they suggest pregnant women consider using the drug for short term pain management, rather than as a long-term solution.
Ann Z. Bauer et al, Paracetamol use during pregnancy—a call for precautionary action, Nature Reviews Endocrinology (2021). DOI: 10.1038/s41574-021-00553-7
https://medicalxpress.com/news/2021-09-scientists-pregnant-women-pa...
Sep 25, 2021
Dr. Krishna Kumari Challa
How do cells react when a chromosome is lost?
Human cells are usually diploid—they contain two sets of chromosome. Cells in which one chromosome is missing from the duplicated chromosome set are generally not viable. For a long time, the mechanisms responsible for the loss of viability were unknown. New research now throws some light on it.
Monosomy occurs when chromosomes are incorrectly distributed during routine cell division and cells subsequently lack one chromosome in an otherwise double (diploid) set. The only form of this deviation in chromosome number (aneuploidy) that human cells can survive is known as Turner syndrome. The hallmark of the hereditary disease, which occurs in women: only one of the two X sex chromosomes is present. However, what happens in human somatic cells that are missing other than sex chromosome had not been explored until now, because monosomic cells are generally not viable.
When monosomy occurs, the protein 'p53," encoded by the so-called tumor suppressor gene TP53, ensures that the cell cycle stops. In other words, the cells stop dividing. Therefore, researchers have switched off this gene in one part of their cell lines, which were originally derived from human retina cell lines, to downregulate the production of the encoded protein. Thus, for the first time, they succeeded in generating stable monosomic cell lines for research purposes.
The research team subsequently focused on the effects of monosomy on proliferation (cell growth/multiplication), genomic stability and how chromosome loss affects the amount of mRNAs and proteins (transcriptome and proteome, respectively). They we observed reduced levels of cytoplasmic ribosomal proteins and reduced protein synthesis (protein translation) in all monosomal cell lines. Accordingly, they hypothesize that chromosome loss impairs ribosomal biogenesis and thereby cellular proliferation. They also showed that this change triggers cell cycle arrest and or senescence via the p53 signaling pathway.
The findings also shed light on the link between cancer and monosomy. Recurrent loss of an entire chromosome or chromosome arm is common in certain tumors, such as neuroblastoma, lung cancer, and myeloid malignancies.
Since monosomies are viable only without p53, scientists predicted that the cancers with monosomy must have defective p53 pathway. The analysis of scientific databases of cancer-related changes, such as "The Cancer Genome Atlas (TCGA)' and "Cancer Cell Lines Encyclopedia (CCLE)", indeed revealed a strong association of monosomy with p53 inactivation and ribosomal pathway impairment.
Narendra Kumar Chunduri et al, Systems approaches identify the consequences of monosomy in somatic human cells, Nature Communications (2021). DOI: 10.1038/s41467-021-25288-x
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Part 1
Sep 25, 2021
Dr. Krishna Kumari Challa
The research team also performed a systematic transcriptome and proteome analysis of monosomic cell lines in comparison to their parental cell lines—i.e., the quantification of all messenger RNAs (mRNAs) transcribed based on DNA, as well as the quantification of all proteins in the cells. As expected, this showed that the expression of genes localized on the monosome was reduced.
Yet, teh researchers observed the lower levels in only 20 percent of the encoded proteins. They suspect that gene dosage effects came into play here. The cells need to return to their 'natural' diploid protein levels to sustain their function and thus compensate for the chromosome loss. Scientists envision two possible scenarios: First, translation of mRNAs encoded using the genes could be selectively increased, or second, protein degradation is reduced. These results suggest that cells use multiple pathways to mitigate the consequences of altered gene expression.
In summary, these scientists present for the first time a successful experimental approach to study the effects of monosomy in human somatic cells.
https://phys.org/news/2021-09-chromosome-lost-human-cells-react.htm...
Part 2
Sep 25, 2021
Dr. Krishna Kumari Challa
A 3D printed vaccine patch offers vaccination without a shot
Scientists have created a 3D-printed vaccine patch that provides greater protection than a typical vaccine shot. The trick is applying the vaccine patch directly to the skin, which is full of immune cells that vaccines target.
The resulting immune response from the vaccine patch was 10 times greater than vaccine delivered into an arm muscle with a needle jab, according to a study conducted in animals and published by the team of scientists in the Proceedings of the National Academy of Sciences.
Considered a breakthrough are the 3D-printed microneedles lined up on a polymer patch and barely long enough to reach the skin to deliver vaccine. The ease and effectiveness of a vaccine patch sets the course for a new way to deliver vaccines that's painless, less invasive than a shot with a needle and can be self-administered.
Study results show the vaccine patch generated a significant T-cell and antigen-specific antibody response that was 50 times greater than a subcutaneous injection delivered under the skin.
That heightened immune response could lead to dose sparing, with a microneedle vaccine patch using a smaller dose to generate a similar immune response as a vaccine delivered with a needle and syringe.
“Transdermal vaccination via 3D-printed microneedles induces potent humoral and cellular immunity” by Cassie Caudill, Jillian L. Perry, Kimon Iliadis, Addis T. Tessema, Brian J. Lee, Beverly S. Mecham, Shaomin Tian and Joseph M. DeSimone, 22 September 2021, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2102595118
https://researchnews.cc/news/9101/A-3D-printed-vaccine-patch-offers...
Sep 26, 2021
Dr. Krishna Kumari Challa
AugLimb: Compact Robotic Limb for Human Augmentation
Sep 26, 2021
Dr. Krishna Kumari Challa
Melting of polar ice shifting Earth itself, not just sea levels
The melting of polar ice is not only shifting the levels of our oceans, it is changing the planet Earth itself. Researchers recently explained in a paper in Geophysical Research Letters that, as glacial ice from Greenland, Antarctica, and the Arctic Islands melts, Earth's crust beneath these land masses warps, an impact that can be measured hundreds and perhaps thousands of miles away.
By analyzing satellite data on melt from 2003 to 2018 and studying changes in Earth's crust, researchers were able to measure the shifting of the crust horizontally. Their research, which was highlighted in Nature, found that in some places the crust was moving more horizontally than it was lifting. In addition to the surprising extent of its reach, the Nature brief pointed out, this research provides a potentially new way to monitor modern ice mass changes.
The implications of this movement are far-reaching. "Understanding all of the factors that cause movement of the crust is really important for a wide range of Earth science problems. For example, to accurately observe tectonic motions and earthquake activity, we need to be able to separate out this motion generated by modern-day ice-mass loss.
Sophie Coulson et al, The Global Fingerprint of Modern Ice‐Mass Loss on 3‐D Crustal Motion, Geophysical Research Letters (2021). DOI: 10.1029/2021GL095477
So much ice is melting that Earth's crust is moving, Nature (2021). DOI: 10.1038/d41586-021-02285-0
https://phys.org/news/2021-09-polar-ice-shifting-earth-sea.html?utm...
Sep 27, 2021
Dr. Krishna Kumari Challa
One more myth busted: Cavers find snakes but no genies in Yemen's 'Well of Hell'
A team of Omani cavers has made what is believed to be the first descent to the bottom of Yemen's fabled Well of Barhout—a natural wonder shunned by many locals, who believe it is a prison for genies.
The forbidding 'Well of Hell', whose dark, round aperture creates a 30-metre (100 foot) wide hole in the desert floor of Yemen's eastern province of Al-Mahra, plunges approximately 112 metres (367 feet) below the surface and, according to some accounts, gives off strange odours.
Inside, the Oman Cave Exploration Team (OCET) found snakes, dead animals and cave pearls—but no signs of the supernatural.
https://phys.org/news/2021-09-cavers-snakes-genies-yemen-hell.html?...
Sep 27, 2021
Dr. Krishna Kumari Challa
Scientists report starch synthesis from carbon dioxide
Scientists recently reported a de novo route for artificial starch synthesis from carbon dioxide (CO2) for the first time.
The new route makes it possible to shift the mode of starch production from traditional agricultural planting to industrial manufacturing, and opens up a new technical route for synthesizing complex molecules from CO2.
Starch is the major component of grain as well as an important industrial raw material. At present, it is mainly produced by crops such as maize by fixing CO2 through photosynthesis. This process involves about 60 biochemical reactions as well as complex physiological regulation. The theoretical energy conversion efficiency of this process is only about 2%.
Strategies for the sustainable supply of starch and use of CO2 are urgently needed to overcome major challenges of mankind, such as the food crisis and climate change. Designing novel routes other than plant photosynthesis for converting CO2 to starch is an important and innovative S&T mission and will be a significant disruptive technology in today's world.
To address this issue, scientists at the Tianjin Institute of Industrial Biotechnology (TIB) of the Chinese Academy of Sciences (CAS) designed a chemoenzymatic system as well as an artificial starch anabolic route consisting of only 11 core reactions to convert CO2 into starch.
This route was established by a "building block" strategy, in which the researchers integrated chemical and biological catalytic modules to utilize high-density energy and high-concentration CO2 in a biotechnologically innovative way.
The researchers systematically optimized this hybrid system using spatial and temporal segregation by addressing issues such as substrate competition, product inhibition, and thermodynamical adaptation.
The artificial route can produce starch from CO2 with an efficiency 8.5-fold higher than starch biosynthesis in maize, suggesting a big step towards going beyond nature. It provides a new scientific basis for creating biological systems with unprecedented functions.
This work would open a window for industrial manufacturing of starch from CO2.
If the overall cost of the process can be reduced to a level economically comparable with agricultural planting in the future, it is expected to save more than 90% of cultivated land and freshwater resources. In addition, it would also help to avoid the negative environmental impact of using pesticides and fertilizers, improve human food security, facilitate a carbon-neutral bioeconomy, and eventually promote the formation of a sustainable bio-based society.
Cai Tao et al, Cell-free chemoenzymatic starch synthesis from carbon dioxide, Science (2021). DOI: 10.1126/science.abh4049
https://phys.org/news/2021-09-chinese-scientists-starch-synthesis-c...
Sep 27, 2021
Dr. Krishna Kumari Challa
The Common Kitchen Ingredient That Could Help if Your Child Swallows a Battery
Every day, and thousands of times a year, a kid swallows a battery.
In the last 20 years or so, this dangerous and sometimes fatal accident has actually become significantly more common in children, and severe injuries caused by button battery ingestion (BBI) have led to a marked increase in hospitalizations.
Thankfully, in most such cases the item ends up passing harmlessly through the patient's digestive tract. However, even tiny batteries can cause tremendous damage if they get stuck in the esophagus.
Young children up to six years of age are most at risk of BBI complications due to their smaller body size, which increases the chance that a swallowed battery might get lodged in their esophagus – especially larger button batteries such as the ubiquitous 20-millimeter CR2032, used in a vast range of small electronics.
Within just two hours, a stuck battery can cause severe burns as its negatively charged surface makes prolonged contact with the conductive tissue of the esophagus; this contact produces an electrical current and breaks nearby water down into a highly corrosive fluid.
If this happens to your child – or you suspect your young, non-verbal child might have swallowed a battery – do not delay. Seek immediate medical attention, as a lodged battery could require urgent endoscopic removal.
However, while you're waiting for medical assistance, researchers now say there is something you can do yourself to mitigate the risk of tissue injury – and it makes use of a condiment many of us have in our kitchens.
According to a newly published research summary on BBI events and complications, honey may help when administered before the patient reaches the hospital, given at 10 milliliters every 10 minutes for children older than one year (up to six doses).
That recommendation is based on a study published in 2018, which explored injury mitigation from button battery blockages in the esophagus using an animal model of young pigs.
In the experiment, researchers tested a range of different household liquids (including honey, maple syrup, Gatorade, and fruit juices) to see whether any of them helped minimize tissue injury resulting from battery lodgment in the animal's esophagus.
Ultimately, two liquids produced the most clinically optimal results: honey, and a product called Carafate, (brand-name version of the medication sucralfate), which is used to treat ulcers and other stomach conditions.
"In the crucial period between button battery ingestion and endoscopic removal, early and frequent ingestion of honey in the household setting and Carafate in the clinical setting has the potential to reduce injury severity and improve patient outcomes.
https://onlinelibrary.wiley.com/doi/epdf/10.1002/lary.27312
https://www.sciencealert.com/the-common-kitchen-ingredient-that-cou...
Sep 28, 2021
Dr. Krishna Kumari Challa
Aspirin and Birth Defects: Fetal Cell Inhibition — Science News, October 2, 1971
Although aspirin has triggered defects in rat and mice fetuses, the evidence suggesting aspirin taken by women during pregnancy can harm their offspring has been circumstantial at best. Now, however … [evidence shows] that aspirin can dramatically arrest the growth of human embryo cells.
Part 1
Sep 29, 2021
Dr. Krishna Kumari Challa
Update
Scientists are still sorting out how aspirin and other nonsteroidal anti-inflammatory drugs, collectively known as NSAIDs, affect pregnancy at every stage. Taking NSAIDs during the first trimester is known to increase the risk of miscarriage . In 2020, the U.S. Food and Drug Administration warned that people who are 20 weeks or more into a pregnancy should avoid using NSAIDs altogether because the drugs can cause rare but serious kidney problems as well as heart problems for fetuses. However, exceptions can be made for pregnant people at risk of preeclampsia , clotting and preterm delivery. In such cases, the FDA recommends that doctors prescribe the lowest effective dose of aspirin.
https://www.sciencenews.org/article/50-years-ago-scientists-found-l...
Part 2
Sep 29, 2021
Dr. Krishna Kumari Challa
Unbelievable DRONE display - Guinness World Records
The longest animation performed by unmanned aerial vehicles (UAVs) is 26 min 19 sec and was achieved by EFYI Group (China) and supported by Tianjin University (China) in Tianjin, China, on 18 December 2020. They depicted the life of Dutch artist Vincent Van Gogh.
Sep 30, 2021
Dr. Krishna Kumari Challa
Making Music from Proteins
Researchers reporting in ACS Nano have found a way to represent a protein’s structure as music.
A Self-Consistent Sonification Method to Translate Amino Acid Sequences into Musical Compositions and Application in Protein Design using Artificial Intelligence.
Sep 30, 2021
Dr. Krishna Kumari Challa
How mercury gets into the sea
Mercury released into the atmosphere by industry enters the sea and from there makes its way into the food chain. Now, an analysis by researchers has revealed how the harmful substance enters seawater in the first place. This is not primarily via rainfall, as previously assumed, but rather also involves gas exchange. Measures to reduce mercury emissions could therefore take effect faster than previously thought.
Every year, 2,000 metric tons of gaseous mercury are released into the atmosphere by coal-fired power stations and mining activities. The harmful substance then adopts various chemical forms as it circulates between the air, soil and water in a complex cycle. Mercury is particularly dangerous in the sea, where it accumulates in fish in the form of highly toxic methylmercury. When this compound enters the human body due to the consumption of fish, it can have an adverse effect on brain development in children and cause cardiovascular diseases in adults.
It's estimated that human activities have tripled the amount of mercury in the surface ocean since the onset of industrialization. Those are just assumptions, however, as there are no collector stations for precipitation over the sea.
The gap was closed by analyzing seawater samples using a new method that allows researchers to distinguish whether mercury originates from precipitation or entered the sea via gas exchange, . Known as "fingerprinting," this technique is based on the measurement of tiny weight differences between naturally occurring mercury atoms, known as isotopes.
The analyses revealed that—contrary to previous assumptions—only about half of the mercury in the sea originates from precipitation, while the other half enters the oceans due to the uptake of gaseous mercury.
Researchers suspect that mercury uptake by plants drives more of the heavy metal to be deposited on land, where it is safely sequestered in soils and poses less of a risk to humans.
The new findings are also important for the implementation of the Minamata Convention of 2013, whereby 133 countries committed to reducing mercury emissions: "If less mercury enters the sea via rainfall, a reduction in emissions could cause mercury levels in seawater to drop faster than anticipated."
Mercury stable isotopes constrain atmospheric sources to the Ocean, Nature (2021). DOI: 10.1038/s41586-021-03859-8 , www.nature.com/articles/s41586-021-03859-8
https://phys.org/news/2021-09-mercury-sea.html?utm_source=nwletter&...
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Sep 30, 2021
Dr. Krishna Kumari Challa
Breath tests could sniff out COVID-19
Since May 2021, drivers crossing into Singapore at the Tuas Checkpoint have been required to breathe into a cigar-sized mouthpiece connected to a mass spectrometer. In less than a minute, the device analyzes the breath samples for COVID-19. According to a new feature article in Chemical & Engineering News, such breath-based diagnostics might be a fast, cheap way to detect infection, although challenges exist.
More than a year into the pandemic, PCR-based assays—which require samples to be collected from patients' nasal passages with a long cotton swab—remain the gold standard for COVID-19 diagnosis. However, such tests are uncomfortable, slow and relatively expensive.
That's why several companies have launched breathalyzer-like tests to detect SARS-CoV-2 infection. These tests rely on altered ratios of volatile organic compounds (VOCs) in exhaled breath, which reflect metabolic changes triggered by the virus. But questions about whether the technology is sufficiently sensitive and reproducible are still unanswered.
One challenge is that researchers haven't sufficiently defined the levels of VOCs in the breath of healthy people, which makes it difficult to accurately measure when someone's exhalation deviates from the norm. As a result, some breath-based tests have had disappointing results when used in real life. Also, some VOCs change similarly in response to different viruses or conditions, making it important to identify unique patterns or ratios of biomarkers that change only upon infection with SARS-CoV-2. Scientists in the field are hopeful that continued standardization and validation will eventually create a robust breath-based diagnostic that might even be able to detect infection earlier than PCR-based tests, before a person begins shedding the virus.
https://phys.org/news/2021-09-covid-.html?utm_source=nwletter&u...
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Sep 30, 2021
Dr. Krishna Kumari Challa
Toxic DNA buildup in eyes may drive blinding macular degeneration
Common HIV drugs could stop vision loss, research suggests
Damaging DNA builds up in the eyes of patients with geographic atrophy, an untreatable, poorly understood form of age-related macular degeneration that causes blindness, new research reveals. Based on the discovery, the researchers think it may be possible to treat the disease with common HIV drugs or an even safer alternative.
Geographic atrophy is an advanced form of age-related macular degeneration, a potentially blinding disease estimated to affect 200 million people around the world. The disease ultimately destroys vital cells in the retina, the light-sensing portion of the eye
A harmful DNA, known as Alu cDNA, was previously discovered to be manufactured in the cytoplasm. The new findings offer insights into how geographic atrophy progresses over time. This finding in human eyes that the levels of toxic Alu cDNA are highest at the leading edge of the geographic atrophy lesion provides strong evidence that it is responsible for this expansion over time that leads to vision loss.
As Alu DNA accumulates in the eye, it triggers harmful inflammation via a part of the immune system called the inflammasome. The researchers identified how this happens, discovering a previously unknown structural facet of Alu that triggers the immune mechanism that leads to the death of the vital retinal cells.
That's where HIV drugs called nucleoside reverse transcriptase inhibitors, or NRTIs, could come in. The researchers' new work in lab mice suggests these drugs, or safer derivatives known as Kamuvudines, could block the harmful inflammation and protect against retinal cell death.
Alu complementary DNA is enriched in atrophic macular degeneration and triggers retinal pigmented epithelium toxicity via cytosolic innate immunity. Science Advances, 2021; 7 (40) DOI: 10.1126/sciadv.abj3658
https://www.sciencedaily.com/releases/2021/09/210930101425.htm
Oct 1, 2021
Dr. Krishna Kumari Challa
Study unveils the quantum nature of the interaction between photons and free electrons
For several decades, physicists have known that light can be described simultaneously as a wave and a particle. This fascinating 'duality' of light is due to the classical and quantum nature of electromagnetic excitations, the processes through which electromagnetic fields are produced.
So far, in all experiments in which light interacts with free electrons, it has been described as a wave. Researchers at Technion—Israel Institute of Technology, however, have recently gathered the first experimental evidence revealing the quantum nature of the interaction between photons and free electrons. Their findings, published in Science, could have important implications for future research investigating photons and their interaction with free electrons.
Raphael Dahan et al, Imprinting the quantum statistics of photons on free electrons, Science (2021). DOI: 10.1126/science.abj7128
Ofer Kfir, Entanglements of Electrons and Cavity Photons in the Strong-Coupling Regime, Physical Review Letters (2019). DOI: 10.1103/PhysRevLett.123.103602
Valerio Di Giulio et al, Probing quantum optical excitations with fast electrons, Optica (2019). DOI: 10.1364/OPTICA.6.001524
https://phys.org/news/2021-09-unveils-quantum-nature-interaction-ph...
Oct 1, 2021
Dr. Krishna Kumari Challa
How complex thoughts take place in the brain
Understanding how the human brain produces complex thought is daunting given its intricacy and scale. The brain contains approximately 100 billion neurons that coordinate activity through 100 trillion connections, and those connections are organized into networks that are often similar from one person to the next. A Dartmouth study has found a new way to look at brain networks using the mathematical notion of fractals, to convey communication patterns between different brain regions as people listened to a short story. The results are published in Nature Communications.
To generate our thoughts, our brains create amazing lightning storm of connection patterns. The patterns look beautiful, but they are also incredibly complicated. Our mathematical framework lets us quantify how those patterns relate at different scales, and how they change over time.
In the field of geometry, fractals are shapes that appear similar at different scales. Within a fractal, shapes and patterns are repeated in an infinite cascade, such as spirals comprised of smaller spirals that are in turn comprised of still-smaller spirals, and so on. Dartmouth's study shows that brain networks organize in a similar way: patterns of brain interactions are mirrored simultaneously at different scales. When people engage in complex thoughts, their networks seem to spontaneously organize into fractal-like patterns. When those thoughts are disrupted, the fractal patterns become scrambled and lose their integrity.
The researchers developed a mathematical framework that identifies similarities in network interactions at different scales or "orders." When brain structures do not exhibit any consistent patterns of interaction, the team referred to this as a "zero-order" pattern. When individual pairs of brain structures interact, this is called a "first-order" pattern. "Second-order" patterns refer to similar patterns of interactions in different sets of brain structures, at different scales. When patterns of interaction become fractal— "first-order" or higher— the order denotes the number of times the patterns are repeated at different scales.
The study shows that when people listened to an audio recording of a 10-minute story, their brain networks spontaneously organized into fourth-order network patterns. However, this organization was disrupted when people listened to altered versions of the recording. For instance, when the story's paragraphs were randomly shuffled, preserving some but not all of the story's meaning, people's brain networks displayed only second-order patterns. When every word of the story was shuffled, this disrupted all but the lowest level (zero-order) patterns.
Part 1
Oct 1, 2021
Dr. Krishna Kumari Challa
The more finely the story was shuffled, the more the fractal structures of the network patterns were disrupted.
Since the disruptions in those fractal patterns seemed directly linked with how well people could make sense of the story, this finding may provide clues about how our brain structures work together to understand what is happening in the narrative."
The fractal network patterns were surprisingly similar across people: patterns from one group could be used to accurately estimate what part of the story another group was listening to.
The team also studied which brain structures were interacting to produce these fractal patterns. The results show that the smallest scale (first-order) interactions occurred in brain regions that process raw sounds. Second-order interactions linked these raw sounds with speech processing regions, and third-order interactions linked sound and speech areas with a network of visual processing regions. The largest-scale (fourth-order) interactions linked these auditory and visual sensory networks with brain structures that support high-level thinking. According to the researchers, when these networks organize at multiple scales, this may show how the brain processes raw sensory information into complex thought—from raw sounds, to speech, to visualization, to full-on understanding.
The researchers' computational framework can also be applied to areas beyond neuroscience and the team has already begun using an analogous approach to explore interactions in stock prices and animal migration patterns.
High-level cognition during story listening is reflected in high-order dynamic correlations in neural activity patterns, Nature Communications (2021). DOI: 10.1038/s41467-021-25876-x
https://medicalxpress.com/news/2021-09-fractal-brain-networks-compl...
Oct 1, 2021
Dr. Krishna Kumari Challa
Earth is dimming due to climate change
Warming ocean waters have caused a drop in the brightness of the Earth, according to a new study.
Researchers used decades of measurements of earthshine—the light reflected from Earth that illuminates the surface of the Moon—as well as satellite measurements to find that there has been a significant drop in Earth's reflectance, or albedo, over the past two decades.
The Earth is now reflecting about half a watt less light per square meter than it was 20 years ago, with most of the drop occurring in the last three years of earthshine data, according to the new study in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.
That's the equivalent of 0.5% decrease in the Earth's reflectance. Earth reflects about 30% of the sunlight that shines on it.
Part 1
Oct 1, 2021
Dr. Krishna Kumari Challa
Two things affect the net sunlight reaching the Earth: the Sun's brightness and the planet's reflectivity. The changes in Earth's albedo observed by the researchers did not correlate with periodic changes in the Sun's brightness, so that means changes in Earth's reflectiveness are caused by something on the Earth.
Specifically, there has been a reduction of bright, reflective low-lying clouds over the eastern Pacific Ocean in the most recent years, according to satellite measurements made as part of NASA's Clouds and the Earth's Radiant Energy System (CERES) project.
That's the same area, off the west coasts of North and South America, where increases in sea surface temperatures have been recorded because of the reversal of a climatic condition called the Pacific Decadal Oscillation, with likely connections to global climate change.
The dimming of the Earth can also be seen in terms of how much more solar energy is being captured by Earth's climate system. Once this significant additional solar energy is in Earth's atmosphere and oceans, it may contribute to global warming , as the extra sunlight is of the same magnitude as the total anthropogenic climate forcing over the last two decades.
P. R. Goode et al, Earth's Albedo 1998–2017 as Measured From Earthshine, Geophysical Research Letters (2021). DOI: 10.1029/2021GL094888
https://phys.org/news/2021-09-earth-dimming-due-climate.html?utm_so...
Part 2
Oct 1, 2021
Dr. Krishna Kumari Challa
'Fight or flight' – unless internal clocks are disrupted, study in mice shows
For humans and animals, many aspects of normal behavior and physiology rely on the proper functioning of the body's circadian clocks.
Here's how it's supposed to work: Your brain sends signals to your body to release different hormones at certain times of the day. For example, you get a boost of the hormone cortisol—nature's built-in alarm system—right before you usually wake up.
But hormone release actually relies on the interconnected activity of clocks in more than one part of the brain. New research from Washington University in St. Louis shows how daily release of glucocorticoids depends on coordinated clock-gene and neuronal activity rhythms in neurons found in two parts of the hypothalamus, the suprachiasmatic nucleus (SCN) and paraventricular nucleus (PVN).
The new study, conducted with freely behaving mice, is published Oct. 1 in Nature Communications.
Normal behavior and physiology depends on a near 24-hour circadian release of various hormones. When hormone release is disrupted, it can lead to numerous pathologies, including affective disorders like anxiety and depression and metabolic disorders like diabetes and obesity.
The daily timing of hormone release is controlled by the SCN. Located in the hypothalamus, just above where the optic nerves cross, neurons in the SCN send daily signals that are decoded in other parts of the brain that talk to the adrenal glands and the body's endocrine system.
"Cortisol in humans (corticosterone in mice) is more typically known as a stress hormone involved in the 'fight or flight' response. But the stress of waking up and preparing for the day is one of the biggest regular stressors to the body. Having a huge amount of this glucocorticoid released right as you wake up seems to help you gear up for the day.
Circadian neurons in the paraventricular nucleus entrain and sustain daily rhythms in glucocorticoids, Nature Communications (2021). DOI: 10.1038/s41467-021-25959-9
https://phys.org/news/2021-10-flight-internal-clocks-disrupted-mice...
Oct 2, 2021
Dr. Krishna Kumari Challa
A breathing tube through the butt could be an alternative to mechanical ventilators
Inspired by animals that breathe through their butts, scientists show that mammals can also harness the incredible breathing ability of our butts.
To survive in extreme low-oxygen conditions deep in the ocean, fish and other creatures have developed remarkable adaptations. For example, sea spiders, loaches, and catfish evolved the ability to breathe through their butts. And they might not be the only butt breathers out there.
A recent study in the journal Med now suggests that mammals, humans included, may be able to breathe through their rear ends as well. Mice, rats, and pigs could all stave off the devastating effects of oxygen deprivation if given an oxygen enema. But could this new method provide temporary oxygen while a patient awaits a ventilator?
Part1
Oct 2, 2021
Dr. Krishna Kumari Challa
While we often consider the butt as the exit for waste in our body, it is also an entryway with lifesaving potential. After all, humans and plenty of other mammals can absorb medications rectally. That’s because there’s a lot of blood vessels in the area, allowing medicine easy entry.
But medicine is specially designed to maximize absorption in the body. Oxygen doesn’t have nearly as easy a path towards entry into the bloodstream through the rectum because of the mucus membrane mammals have on the intestines. There are also important anatomical differences between our intestines and those of fish that already harness this ability. Animals that can breathe through their butts, like loaches, had a much thinner epithelium in their guts and a lot less mucus. During the course of early development, a butt-breathing genetic pathway is turned on that helps dictate the structure of the intestine. When it’s all said and done, the posterior end of the intestine is equipped with all the structures necessary for respiration (and gas exchange).
Would this mucus prevent oxygenation in mice? In the first experiment, researchers used a model of oxygen deprivation in mice, preventing them from breathing through their lungs. The control group didn’t receive any intestinal ventilation, one group received oxygen through an anal catheter, and the final group had the mucus layer on their intestines “scrubbed” before receiving anal ventilation.
Remarkably, the mice supplied oxygen through their anus had elevated oxygen levels in their blood. The final group that also had their intestinal mucus scrubbed fared even better, surviving the longest in the low-oxygen conditions — five times as long as the control group. This experiment proved that there is potential for mammals to breathe through their butt, however, the mucus layer covering the intestinal epithelial cells makes it more difficult.
In a clinical setting, scrubbing the mucus off of a person’s intestines isn’t really feasible, and doesn’t sound like a pleasant experience. But using a method akin to an enema may work, by infusing safe, oxygenated liquid through the butt. This liquid, called perfluorodecalin, could safely store and deliver oxygen via an enema. Due to the properties of this liquid, it doesn’t need to scrub the mucus off of the intestines, meaning less discomfort and abrasion. Oxygen diffuses into the bloodstream while carbon dioxide diffuses out. Since it holds a lot of oxygen and carbon dioxide very easily, it is also delivered safely to the lungs, and is already in clinical use.
Part2
Oct 2, 2021
Dr. Krishna Kumari Challa
During COVID-19, many hospitals find themselves short on ventilators. During the pandemic, many will require the use of a ventilator for an average of 15 days, while a few people will need significantly more time. Ventilators aren’t something that a person can use for one day and then get discharged. The first wave of people requiring ventilators will receive them immediately. However, someone whose lungs fail the next day may need to survive for two weeks without one.
https://next.massivesci.com/articles/rectal-breathing-oxygen-enema-...
Part 3
Oct 2, 2021
Dr. Krishna Kumari Challa
The Scientific Problem of Consciousness
Oct 2, 2021