Human cells harness power of detergents to wipe out bacteria
Cells, like many of us, fend off germs with cleaning products. Researchers have discovered that a molecule made throughout much of the body wipes out invading bacteria like a detergent attacking an oily stain.
This killer cleaner, a protein known as APOL3, thwarts infections by dissolving bacterial membranes. Researchers tested the protein on the food-poisoning bacteria Salmonella and other similar microbes.
The work offers new insight into how human cells defend themselves against infection, a process termed cell-autonomous immunity. While scientists knew that cells could attack bacterial membranes, this study uncovers what appears to be the first example of a protective intracellular protein with detergent-like action.
Thinking without a brain: Studies in brainless slime molds reveal that they use physical cues to decide where to grow
Scientists have discovered that a brainless slime mold called Physarum polycephalum uses its body to sense mechanical cues in its surrounding environment, and performs computations similar to what we call "thinking" to decide in which direction to grow based on that information. Unlike previous studies with Physarum, these results were obtained without giving the organism any food or chemical signals to influence its behavior. The study is published in Advanced Materials.
Physarum is interesting because it doesn't have a brain but it can still perform a lot of the behaviours that we associate with thinking, like solving mazes, learning new things, and predicting events. Figuring out how proto-intelligent life manages to do this type of computation gives us more insight into the underpinnings of animal cognition and behavior, including our own.
The team's research demonstrated that this brainless creature was not simply growing toward the heaviest thing it could sense—it was making a calculated decision about where to grow based on the relative patterns of strain it detected in its environment.
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Slime molds are amoeba-like organisms that can grow to be up to several feet long, and help break down decomposing matter in the environment like rotting logs, mulch, and dead leaves. A single Physarum creature consists of a membrane containing many cellular nuclei floating within a shared cytoplasm, creating a structure called a syncytium. Physarum moves by shuttling its watery cytoplasm back and forth throughout the entire length of its body in regular waves, a unique process known as shuttle streaming. With most animals, we can't see what's changing inside the brain as the animal makes decisions. Physarum offers a really exciting scientific opportunity because we can observe its decisions about where to move in real-time by watching how its shuttle streaming behavior changes.
While previous studies have shown that Physarum moves in response to chemicals and light, Murugan and her team wanted to know if it could make decisions about where to move based on physical cues in its environment alone.
The researchers placed Physarum specimens in the center of petri dishes coated with a semi-flexible agar gel and placed either one or three small glass discs next to each other atop the gel on opposite sides of each dish. They then allowed the organisms to grow freely in the dark over the course of 24 hours, and tracked their growth patterns. For the first 12 to 14 hours, the Physarum grew outwards evenly in all directions; after that, however, the specimens extended a long branch that grew directly over the surface of the gel toward the three-disc region 70% of the time. Remarkably, the Physarum chose to grow toward the greater mass without first physically exploring the area to confirm that it did indeed contain the larger object.
The researchers experimented with several variables to see how they impacted Physarum's growth decisions, and noticed something unusual: when they stacked the same three discs on top of each other, the organism seemed to lose its ability to distinguish between the three discs and the single disc. It grew toward both sides of the dish at roughly equal rates, despite the fact that the three stacked discs still had greater mass. Clearly, Physarum was using another factor beyond mass to decide where to grow.
To figure out the missing piece of the puzzle, the scientists used computer modeling to create a simulation of their experiment to explore how changing the mass of the discs would impact the amount of stress (force) and strain (deformation) applied to the semi-flexible gel and the attached growing Physarum. As they expected, larger masses increased the amount of strain, but the simulation revealed that the strain patterns the masses produced changed, depending on the arrangement of the discs.
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But how was it detecting these strain patterns? The scientists suspected it had to do with Physarum's ability to rhythmically contract and tug on its substrate, because the pulsing and sensing of the resultant changes in substrate deformation allows the organism to gain information about its surroundings.
Researchers create snake-venom-derived 'super glue' that stops bleeding in seconds
This super glue is based on a new discovery on a blood clotting enzyme called reptilase or batroxobin found in the venom of lancehead snakes (Bothrops atrox), which are amongst the most poisonous snakes in South America.
Taking advantage of this clotting property, researchers designed a body tissueadhesive that incorporates the special enzyme into a modified gelatin that can be packaged into a small tube for easy, and potentially life-saving, application.
During trauma, injury and emergency bleeding, this 'super glue' can be applied by simply squeezing the tube and shining a visible light, such as a laser pointer, over it for few seconds. Even a smartphone flashlight will do the job.
Compared to clinical fibrin glue, considered the industry gold standard for clinical and field surgeons, the new tissue sealant has 10 times the adhesive strength to resist detachment or washout due to bleeding. The blood clotting time is also much shorter, cutting it in half from 90 seconds for fibrin glue to 45 seconds for the new snakevenom "super glue."
This new biotechnology translates to less blood loss and more life-saving. The super-sealant was tested in models for deep skin cuts, ruptured aortae, and severely injured livers—all considered as major bleeding situations.
Yicheng Guo et al, Snake extract–laden hemostatic bioadhesive gel cross-linked by visible light, Science Advances (2021). DOI: 10.1126/sciadv.abf9635
Professors in Syracuse University's College of Arts and Sciences explored whether or not the scientific community will ever be able to settle on a 'total number' of species of living vertebrates, which could help with species preservation. By knowing what's out there, researchers argue that they can prioritize places and groups on which to concentrate conservation efforts.
Bruce H Wilkinson et al, Estimating vertebrate biodiversity using the tempo of taxonomy – a view from Hubbert's peak, Biological Journal of the Linnean Society (2021). DOI: 10.1093/biolinnean/blab080
‘Super-antibodies’ could curb COVID-19 and help avert future pandemics
Companies are designing next-generation antibodies modeled on those taken from unique individuals whose immune systems can neutralize any COVID-19 variant—and related coronaviruses, too.
A new generation of designer antibodies could help to treat a wide range of SARS-CoV-2 variants — and future coronaviruses with pandemic potential. ‘Super-antibodies’ are modelled on antibodies taken from rare individuals whose immune systems can neutralize any SARS-CoV-2 variant and related coronaviruses.
Just 7% of our DNA is unique to modern humans, study shows
What makes humans unique? Scientists have taken another step toward solving an enduring mystery with a new tool that may allow for more precise comparisons between the DNA of modern humans and that of our extinct ancestors.
Just 7% of our genomeis uniquely shared with other humans, and not shared by other early ancestors, according to a study published Friday in the journalScience Advances.
That's a pretty small percentage. This kind of finding is why scientists are turning away from thinking that we humans are so vastly different from Neanderthals.
The research draws upon DNA extracted fromfossil remainsof now-extinct Neanderthals and Denisovans dating back to around 40,000 or 50,000 years ago, as well as from 279 modern people from around the world.
Scientists already know that modern people share some DNA with Neanderthals, but different people share different parts of the genome. One goal of the new research was to identify the genes that are exclusive to modern humans.
It's a difficult statistical problem, and the researchers developed a valuable toolthat takes account of missing data in the ancient genomes.
The researchers also found that an even smaller fraction of our genome—just 1.5%—is both unique to our species and shared among all people alive today. Those slivers of DNA may hold the most significant clues as to what truly distinguishes modern human beings.
Scientists now can tell those regions of the genome are highly enriched for genes that have to do with neural development and brain function.
Nathan K. Schaefer et al, An ancestral recombination graph of human, Neanderthal, and Denisovan genomes, Science Advances (2021). DOI: 10.1126/sciadv.abc0776
Common medication used to reduce cholesterol levels may reduce COVID-19 severity
In a new study, researchers have confirmed that patients taking statin medications had a 41 percent lower risk of in-hospital death from COVID-19. The findings were published July 15, 2021 in PLOS ONE.
Statins are commonly used to reduce blood cholesterol levels by blocking liver enzymes responsible for making cholesterol. They are widely prescribed.
When faced with this virus at the beginning of the pandemic, there was a lot of speculation surrounding certain medications that affect the body's ACE2 receptor, including statins, and whether they may influence COVID-19 risk. At the time, scientists thought that statins may inhibit SARS-CoV-2 infection through their known anti-inflammatory effects and binding capabilities, which could potentially stop progression of the virus.
Researchers now analyzed anonymized medical recordsof 10,541 patients admitted for COVID-19 over a nine-month period, January through September 2020, at 104 different hospitals.
From this data, they performed more advanced analyses as they attempted to control for coexisting medical conditions, socioeconomic status and hospital factors. In doing so, they confirmed their prior findings that statins are associated with a reduced risk of death from COVID-19 among patients hospitalized for COVID-19.
It appears most of the benefit is among patients with good medical reasons to be taking statins, such as a history of cardiovascular disease or high blood pressure. According to the research team, the use of statins or an anti-hypertension medication was associated with a 32 percent lower riskof death among COVID-19 inpatients with a history of cardiovascular disease or hypertension.
In the study, statistical matching techniques were used to compare outcomes for patients who used statins or an anti-hypertension medication with similar patients who did not.
The ACE2 receptor—the regulatory target of statins—helps control blood pressure. In 2020, it was discovered that SARS-CoV-2 virus primarily uses the same receptor to enter lung cells.
According to researchers, statins and anti-hypertension medications stabilize the underlying diseases for which they are prescribed, making patients more likely to recover from COVID-19.
As with any observational study, researchers cannot say for certain that the associations they describe between statin use and reduced severity of COVID-19 infection are definitely due to the statins themselves; however, they can now say with very strong evidence that they may play a role in substantially lowering a patient's risk of death from COVID-19.
Lori B. Daniels et al, Relation of prior statin and anti-hypertensive use to severity of disease among patients hospitalized with COVID-19: Findings from the American Heart Association's COVID-19 Cardiovascular Disease Registry, PLOS ONE (2021). DOI: 10.1371/journal.pone.0254635
Antibiotics in early life could affect brain development
Antibiotic exposure early in life could alter human brain development in areas responsible for cognitive and emotional functions, according to some researchers. The laboratory study, published in the journal iScience, suggests that penicillin changes the microbiome the trillions of beneficial microorganisms that live in and on our bodies as well as gene expression, which allows cells to respond to its changing environment, in key areas of the developing brain. The findings suggest reducing widespread antibiotic use or using alternatives when possible to prevent neurodevelopment problems. Penicillin and related medicines (like ampicillin and amoxicillin) are the most widely used antibiotics in children worldwide.
Previous work has shown that exposing young animals to antibiotics changes their metabolism and immunity. The third important development in early life involves the brain. This study is preliminary but shows a correlation between altering the microbiome and changes in the brain that should be further explored.
The study compared mice that were exposed to low-dose penicillin in utero or immediately after birth to those that were not exposed. They found that mice given penicillin experienced substantial changes in their intestinal microbiota and had altered gene expression in the frontal cortex and amygdala, two key areas in the brain responsible for the development of memory as well as fear and stress responses.
A growing body of evidence links phenomena in the intestinal tract with signaling to the brain, a field of study known as the “gut-brain-axis.” If this pathway is disturbed, it can lead to permanent altering of the brain’s structure and function and possibly lead to neuropsychiatric or neurodegenerative disorders in later childhood or adulthood.
Angelina Volkova, Kelly Ruggles, Anjelique Schulfer, Zhan Gao, Stephen D. Ginsberg, Martin J. Blaser.Effects of early-life penicillin exposure on the gut microbiome and frontal cortex and amygdala gene expression.iScience, 2021; 102797 DOI:10.1016/j.isci.2021.102797
A new study has identified 203 different long COVID symptoms across 10 different organ systems in the body, highlighting just how widespread and varied the affliction is and how it can interfere with many different aspects of daily life.
With a total of 3,762 people quizzed across 56 countries, the international study is the biggest and most comprehensive look yet at how 'long haulers' continue to have problems way beyond the normal timescale of COVID-19.
The most commonly reported symptoms were fatigue, post-exertional malaise (symptoms getting worse after physical or mental effort), and cognitive dysfunction or 'brain fog'. Other symptoms included visual hallucinations, tremors, sexual dysfunction, memory loss, and diarrhea – a whole range of physical and cognitive health issues.
On average, participants reported 55.9 symptoms each, across 9.1 organ systems. Of the 3,762 respondents with long COVID, 2,454 had experienced symptoms for at least six months. All that takes a toll: 45.2 percent of participants said they had reduced their working hours, while 22.3 percent were not working at all at the time of the survey.
"By seven months, many patients have not yet recovered (mainly from systemic and neurological/cognitive symptoms), have not returned to previous levels of work, and continue to experience significant symptom burden," write the researchers in their published paper.
Common COVID-19 antibiotic no more effective than placebo
A new study has found that the antibiotic azithromycin was no more effective than a placebo in preventing symptoms of COVID-19 among non-hospitalized patients, and may increase their chance of hospitalization, despite widespread prescription of the antibiotic for the disease.
These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection.
Azithromycin, a broad-spectrum antibiotic, is widely prescribed as a treatment for COVID-19 in the United States and the rest of the world. The hypothesis is that it has anti-inflammatory properties that may help prevent progression if treated early in the disease. But this was found to be untrue.
The study was published in the Journal of the American Medical Association
Global satellite data shows clouds will amplify global heating
A new approach to analyze satellite measurements of Earth's cloud cover reveals that clouds are very likely to enhance global heating.
The research is the strongest evidence yet that clouds will amplify global heating over the long term, further exacerbating climate change.
It also suggest that at double atmospheric carbon dioxide (CO2) concentrations above pre-industrial levels, the climate is unlikely to warm below 2°C, and is more likely on average to warm more than 3°C.
Pre-industrial CO2levels were around 280 ppm (parts per million), but current levels are approaching 420 ppm, and could approach double the pre-industrial amount by mid-century if significant emissions cuts are not made. The amount of climatewarmingpredicted from a doubling of pre-industrial CO2levels is known as the 'climate sensitivity' - a measure of how strongly our climate will react to such a change.
The largest uncertainty in climate sensitivity predictions is the influence of clouds, and how they may change in the future. This is because clouds, depending on properties such as their density and height in the atmosphere, can either enhance or dampen warming.
Low clouds tend to have a cooling effect, as they block the sun from reaching the ground. High clouds, however, have a warming effect, as while they let solar energy reach the ground, the energy emitted back from the Earth is different. This energy can be trapped by the clouds, enhancing the greenhouse effect. Therefore, the type and amount of cloud a warming world will produce impacts further warming potential.
Researchers say they have discovered unique and exciting DNA strands in the mud — others aren’t sure of their novelty.
Scientists analysing samples from muddy sites in the western United States have found novel DNA structures that seem to scavenge and ‘assimilate’ genes from microorganisms in their environment, much like the fictional Star Trek ‘Borg’ aliens who assimilate the knowledge and technology of other species.
These extra-long DNA strands, which the scientists named in honour of the aliens, join a diverse collection of genetic structures — circular plasmids, for example — known as extrachromosomal elements (ECEs). Most microbes have one or two chromosomes that encode their primary genetic blueprint. But they can host, and often share between them, many distinct ECEs. These carry non-essential but useful genes, such as those for antibiotic resistance.
Borgs are a previously unknown, unique and “absolutely fascinating” type of ECE. Borgs are DNA structures “not like any that’s been seen before”. Most scientists agree that the find is exciting, but some have questioned whether Borgs really are unique, noting similarities between them and other large ECEs.
Their vast size, ranging between more than 600,000 and about 1 million DNA base pairs in length, is one feature that distinguishes Borgs from many other ECEs. In fact, Borgs are so huge that they are up to one-third of the length of the main chromosome in their host microbes.
In the 1970s four spacecraft began their one-way trips out of our Solar System. As the first human-built objects to ever venture into interstellar space, NASA chose to place plaques on Pioneer 10 and 11 and golden records on Voyager 1 and 2 spacecraft to serve as messages to any alien spacefarers that may someday encounter these spacecraft. Continuing this legacy, NASA's Lucy spacecraft will carry a similar plaque. However, because Lucy will not be venturing outside of our Solar System, Lucy's plaque is a time-capsule featuring messages to our descendants.
No more broken mobile screens: Bengal researchers develop self-healing material
The research on the material, that scientists said can repair themselves within milliseconds when fractured, has made it to the coveted Science journal.
A group of researchers from the Indian Institute of Science Education and Research (IISER) Kolkata and Indian Institute of Technology Kharagpur, developed a new class of materials that they claim can repair themselves when fractured, within milliseconds.
The research has also made it to the coveted Science journal published by the American Association for the Advancement of Science. The scientists claimed that the highly crystalline materials, when broken into pieces, can self-heal and re-join in a matter of a second, and repair themselves so precisely that they become indistinguishable from the undisturbed materials.
The scientists hope that the discovery can spark a revolution in the field of digital technology, such as broken screens of gadgets and other new-age technologies.
The researchers said materials applied in technologies undergo mechanical impacts which often make the devices irreparable. The idea prompted the team to delve deep in search of self-repairing materials to enhance the longevity of the devices without external intervention.
Researchers developed a new class of solid materials that with a head-to-tail (positive end-to-negative end) polar arrangement in the crystalline state generates opposite electrical potentials at the fractured surfaces. These charges allow instant recombination and self-repair of the broken crystals without any external help. The scientists said that during the repair, fractured pieces travel with a honeybee wing-like motion with acceleration comparable to diesel cars.
Another team from IISER used a custom-designed state-of-the-art polarisation microscopic system to probe and quantify the structural order of the piezoelectric self-healing organic crystals with nanometer-scale spatial resolution.
The scientists said that these crystals, which belong to a general class of piezoelectric materials, can generate electricity under pressure, which in turn can heal and retain their crystalline nature which is important for many applications.
The development of an ultrathin magnet that operates at room temperature could lead to new applications in computing and electronics—such as high-density, compact spintronic memory devices—and new tools for the study of quantum physics.
The ultrathin magnet, which was recently reported in the journal Nature Communications, could make big advances in next-gen memories, computing, spintronics, and quantum physics.
This discovery is exciting because it not only makes 2-D magnetismpossible at room temperature, but it also uncovers a new mechanism to realize 2-D magnetic materials.
zinc oxide's free electrons could act as an intermediary that ensures the magnetic cobalt atoms in the new 2-D device continue pointing in the same direction—and thus stay magnetic—even when the host, in this case the semiconductor zinc oxide, is a nonmagnetic material.
Rui Chen et al, Tunable room-temperature ferromagnetism in Co-doped two-dimensional van der Waals ZnO, Nature Communications (2021). DOI: 10.1038/s41467-021-24247-w
Microbially produced fibers: Stronger than steel, tougher than Kevlar
Spider silk is said to be one of the strongest, toughest materials on the Earth. Now engineers have designed amyloid silk hybrid proteins and produced them in engineered bacteria. The resulting fibers are stronger and tougher than some natural spider silks.
The artificial silk—dubbed "polymeric amyloid" fiber—was not technically produced by researchers, but by bacteria that were genetically engineered in the lab.
Jingyao Li et al, Microbially Synthesized Polymeric Amyloid Fiber Promotes β-Nanocrystal Formation and Displays Gigapascal Tensile Strength, ACS Nano (2021). DOI: 10.1021/acsnano.1c02944
Study finds calcium precisely directs blood flow in the brain
Unlike the rest of the body, there is not enough real estate in the brain for stored energy. Instead, the brain relies on the hundreds of miles of blood vessels within it to supply fresh energy via the blood. Yet, how the brain expresses a need for more energy during increased activity and then directs its blood supply to specific hot spots was, until now, poorly understood.
Now, researchers have shown how the brain communicates to blood vessels when in need of energy, and how these blood vessels respond by relaxing or constricting to direct blood flow to specific brain regions.
If the brain does not get blood to where it needs it when it needs it, the neurons become stressed, and over time they deteriorate ultimately leading to cognitive decline and memory problems.
Large arteries feed medium-sized vessels known as arterioles that then feed even tinier capillaries—so small that only a single blood cell can pass through at once. In a 2017 Nature Neuroscience paper, the researchers showed that electrical pulses coursing through the capillaries direct blood flow from the medium-sized arterioles supplying large regions of the brain. For this latest paper, the team studied the fine-tuning of blood as it flows through the capillaries to precisely regulate energy supply to tiny regions in the brain.
There seem to be two mechanisms working in tandem to ensure that energy in the form of blood makes it to specific regions of the brain: one broad and the other precise. The first electrical mechanism is like a crude sledgehammer approach to get more blood to the general vicinity of the increased brain activity by controlling the medium-sized arterioles, and then capillary calcium signals ensure exquisite fine-tuning to make sure the blood gets to exactly the right place at the right time through the tiny capillaries.
Rounding errors could make certain stopwatches pick wrong race winners
As the Summer Olympics draw near, the world will shift its focus to photo finishes and races determined by mere fractions of a second. Obtaining such split-second measurements relies on faultlessly rounding a raw time recorded by a stopwatch or electronic timing system to a submitted time.
Researchers now found certain stopwatches commit rounding errors when converting raw times to final submitted times. They outline a series of computer simulations based on procedures for converting raw race times for display.
These researchers were inspired when they encountered the issue firsthand while volunteering at a swim meet. While helping input times into the computer, they noticed a large portion of times they inputted were rounded to either the closest half-second or full second.
Later, when the frequencies of the digit pairs were plotted, a distinct pattern emerged. They discovered that the distribution of digit pairs was statistically inconsistent with the hypothesis that each digit pair was equally likely, as one would expect from stopwatches.
Stopwatches and electronic timing systems use quartz oscillators to measure time intervals, with each oscillation calculated as 0.0001 seconds. These times are then processed for display to 0.01 seconds, for example, to the public at a sporting venue.
When the researchers processed raw times through the standard display routine, the uniform distribution disappeared. Most times were correctly displayed.
Where rounding errors occurred, they usually resulted in changes of one one-hundredth of a second. One raw time of 28.3194 was converted to a displayed time of 28.21.
The researchers collected more than 30,000 race times from swimming competitions and will investigate if anomalous timing patterns appear in the collection, which would suggest the potential for rounding errors in major sporting events.
David A. Faux et al, The floating point: Rounding error in timing devices, American Journal of Physics (2021). DOI: 10.1119/10.0003919
The roaring Bootleg Fire burning up swaths of southwestern Oregon is the nation's largest wildfire so far this year and intense enough that it's triggering weather phenomena, including lightning, massive columns of smoke and ash clouds reaching high into the atmosphere, and even the possibility of a "fire tornado." Loretta Mickley, senior research fellow in chemistry-climate interactions at the Harvard John A. Paulson School of Engineering and Applied Sciences, has examined the interaction of wildfires and climate and published research on the likelihood that the wildfires will grow larger and more frequent in the years to come. The Gazette spoke to Mickley to better understand the causes, dangers, and expectations for the future.
Any life identified on planets orbiting white dwarf stars almost certainly evolved after the star's death, says a new study led by the University of Warwick that reveals the consequences of the intense and furious stellar winds that will batter a planet as its star is dying. The research is published in Monthly Notices of the Royal Astronomical Society, and lead author Dr. Dimitri Veras will present it today (21 July) at the online National Astronomy Meeting (NAM 2021).
A Twitter user has found and made public a Windows 10/11 vulnerability that exposes admin passwords to local users who can then escalate their privileges up to admin, giving them total system access. As he notes on his posts, he found that Windows Security Account Manager (SAM) data could be read by users with very limited privileges, giving them access to admin passwords. Microsoft apparently caught wind of the vulnerability and posted an Executive Summary of the issue on its Security Vulnerability page.
RNA breakthrough creates crops that can grow 50% more potatoes, rice
Manipulating RNA can allow plants to yield dramatically more crops, as well as increasing drought tolerance, announced a group of scientists.
In initial tests, adding a gene encoding for a protein called FTO to both rice and potato plants increased their yield by 50% in field tests. The plants grew significantly larger, produced longer root systems and were better able to tolerate drought stress. Analysis also showed that the plants had increased their rate of photosynthesis.
The change really is dramatic. What's more, it worked with almost every type of plant scientists tried it with so far, and it's a very simple modification to make.
We know that the RNA molecule reads DNA, then makes proteins to carry out tasks. But RNA doesn't simply read the DNA blueprint and carry it out blindly; the cell itself can also regulate which parts of the blueprint get expressed. It does so by placing chemical markers onto RNA to modulate which proteins are made and how many. Scientists realized that this had major implications for biology.
They focused on a protein called FTO, the first known protein that erases chemical marks on RNA. The scientists knew it worked on RNA to affect cell growth in humans and other animals, so they tried inserting the gene for it into rice plants—and then watched in amazement as the plants took off.
The rice plants grew three times more rice under laboratory conditions. When they tried it out in real field tests, the plants grew 50% more mass and yielded 50% more rice. They grew longer roots, photosynthesized more efficiently, and could better withstand stress from drought.
The scientists repeated the experiments with potato plants, which are part of a completely different family. The results were the same.
That suggested a degree of universality that was extremely exciting.
It took the scientists longer to begin to understand how this was happening. Further experiments showed that FTO started working early in the plant's development, boosting the total amount of biomass it produced.
The scientists think that FTO controls a process known as m6A, which is a key modification of RNA. In this scenario, FTO works by erasing m6A RNA to muffle some of the signals that tell plants to slow down and reduce growth.
How newborn mammals dream the world they're entering
As a newborn mammal opens its eyes for the first time, it can already make visual sense of the world around it. But how does this happen before they have experienced sight?
A new study suggests that, in a sense, mammals dream about the world they are about to experience before they are even born.
Scientists describe the process as waves of activity that emanate from the neonatal retina in mice before their eyes ever open.
This activity disappears soon after birth and is replaced by a more mature network of neural transmissions of visual stimuli to the brain, where information is further encoded and stored.
But how do the circuits form that allow us to perceive motion and navigate the world? It turns out we are born capable of many of these behaviors, at least in rudimentary form.
Scientists explored the origins of these waves of activity. Imaging the brains of mice soon after birth but before their eyes opened, the Yale team found that these retinal waves flow in a pattern that mimics the activity that would occur if the animal were moving forward through the environment.
This early dream-like activity makes evolutionary sense because it allows a mouse to anticipate what it will experience after opening its eyes, and be prepared to respond immediately to environmental threats.
They also investigated the cells and circuits responsible for propagating the retinal waves that mimic forward motion in neonatal mice. They found that blocking the function of starburst amacrine cells, which are cells in the retina that release neurotransmitters, prevents the waves from flowing in the direction that mimics forward motion. This in turn impairs the development of the mouse's ability to respond to visual motion after birth.
Intriguingly, within the adult retina of the mouse these same cells play a crucial role in a more sophisticated motion detection circuit that allows them to respond to environmental cues.
Mice, of course, differ from humans in their ability to quickly navigate their environment soon after birth. However, human babies are also able to immediately detect objects and identify motion, such as a finger moving across their field of vision, suggesting that their visual system was also primed before birth.
These brain circuits are self-organized at birth and some of the early teaching is already done. It's like dreaming about what you are going to see before you even open your eyes.
In a preprint posted 12 July1, the researchers report that virus was first detectable in people with the Delta variant four days after exposure,compared with an average of six days among people with the original strain, suggesting that Delta replicates much faster. Individuals infected with Delta also had viral loads up to 1,260 times higher than those in people infected with the original strain.
The combination of a high number of viruses and a short incubation period makes sense as an explanation for Delta’s heightened transmissibility.
The sheer amount of virus in the respiratory tract means thatsuperspreadingevents are likely to infect even more people, and that people might begin spreading the virus earlier after they become infected.
And the short incubation makescontact tracingmore difficult in some countries.
Putting it all together, Delta’s really difficult to stop.
The highly contagious Delta variant of Covid-19 is expected to become the dominant strain of the virus over the coming months, according to the World Health Organization.
The science of underwater swimming: How staying submerged gives Olympians the winning edge
To win swimming gold in Tokyo, swimmers not only have to generate incredible power with their arms and legs to propel themselves through the water; they also have to overcome the relentless pull of the water's drag while doing so.
Without being able to don special low-drag suits or use technologies to help them fly over the water, how can swimmers make the effect of the water's drag as small as possible?
The best athletesin this year's Olympics will do it by swimming under, rather than on top of, the water—at least as far as the rules allow.
Water is much denser than air, so you might assume swimmers would benefit from using a technique that allows them to sit high in the water, with as much of their body out of the water as possible.
But there are two problems with this strategy.
First, it costs energy to produce the forces needed to lift the body, which would be better spent propelling theswimmerforwards towards the finishing wall.
Second, when we travel on the water's surface we waste energy making waves. During fast swimming, such as in the sprint freestyle events or during starts and turns (where speeds exceed 2 meters per second, or about 7 kilometers per hour), wave generation slows the swimmer down more than any other factor. Reducing wave formation is therefore vital to swimming success.
Waves are produced as the pressure exerted by the swimmer on the water forces the water upwards and out of their path. Other pressure changes around the swimmer's body also cause waves to form behind them, and sometimes to the side.
The energy required to generate waves comes from the swimmer themselves, so a lot of the power generated by the swimmer's muscles is used in wave generation rather than moving the swimmer forwards.
But waves aren't formed when we (or fish, dolphins or whales) swim under the water, because wavesonly form when an object (like us) moves at the boundary between two fluids of different densities, such as water and air during swimming. And this fact hints at an intriguing solution to the drag issue.
Here, the swimmer propels themselves underwater by undulating the lower body in a wave-like manner while maintaining a rigid and streamlined upper body position with arms stretched overhead.
The amplitude of the lower body undulation increases from the hips to the feet so the "wave" produced by the body is much greater down towards the feet, creating a whip-like effect. This pushes water rapidly backwards, propelling the swimmer forwards according to Newton's law of action and reaction.
Although some aspects of underwater swimming is banned, the benefits of improving the underwater undulation technique are so great that swimmers still spend hours each week in training improving this part of the race.
Scientists reverse age-related memory loss in mice
In a study published in Molecular Psychiatry, a research team show that changes in the extracellular matrix of the brain scaffolding around nerve cells lead to loss of memory with ageing, but that it is possible to reverse these using genetic treatments. Recent evidence has emerged of the role of perineuronal nets (PNNs) in neuroplasticity the ability of the brain to learn and adapt and to make memories. PNNs are cartilage-like structures that mostly surround inhibitory neurons in the brain. Their main function is to control the level of plasticity in the brain. They appear at around five years old in humans, and turn off the period of enhanced plasticity during which the connections in the brain are optimised. Then, plasticity is partially turned off, making the brain more efficient but less plastic. PNNs contain compounds known as chondroitin sulphates. Some of these, such as chondroitin 4-sulphate, inhibit the action of the networks, inhibiting neuroplasticity; others, such as chondroitin 6-sulphate, promote neuroplasticity. As we age, the balance of these compounds changes, and as levels of chondroitin 6-sulphate decrease, so our ability to learn and form new memories changes, leading to age-related memory decline.
They investigated whether manipulating the chondroitin sulphate composition of the PNNs might restore neuroplasticity and alleviate age-related memory deficits.
To do this, the team looked at 20-month old mice – considered very old – and using a suite of tests showed that the mice exhibited deficits in their memory compared to six-month old mice.
For example, one test involved seeing whether mice recognised an object. The mouse was placed at the start of a Y-shaped maze and left to explore two identical objects at the end of the two arms. After a short while, the mouse was once again placed in the maze, but this time one arm contained a new object, while the other contained a copy of the repeated object. The researchers measured the amount of time the mouse spent exploring each object to see whether it had remembered the object from the previous task. The older mice were much less likely to remember the object.
The team treated the ageing mice using a ‘viral vector’, a virus capable of reconstituting the amount of 6-sulphate chondroitin sulphates to the PNNs and found that this completely restored memory in the older mice, to a level similar to that seen in the younger mice.
Sujeong Yang, Sylvain Gigout, Angelo Molinaro, Yuko Naito-Matsui, Sam Hilton, Simona Foscarin, Bart Nieuwenhuis, Chin Lik Tan, Joost Verhaagen, Tommaso Pizzorusso, Lisa M. Saksida, Timothy M. Bussey, Hiroshi Kitagawa, Jessica C. F. Kwok, James W. Fawcett.Chondroitin 6-sulphate is required for neuroplasticity and memory in ageing.Molecular Psychiatry, 2021; DOI:10.1038/s41380-021-01208-9
15,000-year-old viruses discovered in Tibetan glacier ice
Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.
The findings, published today in the journal Microbiome, could help scientists understand how viruses have evolved over centuries. For this study, the scientists also created a new, ultra-clean method of analyzing microbes and viruses in ice without contaminating it.
The researchers analyzed ice cores taken in 2015 from the Guliya ice cap in western China. The cores are collected at high altitudes—the summit of Guliya, where this ice originated, is 22,000 feet above sea level. The ice cores contain layers of ice that accumulate year after year, trapping whatever was in the atmosphere around them at the time each layer froze. Those layers create a timeline of sorts, which scientists have used to understand more about climate change, microbes, viruses and gasses throughout history.
Researchers determined that the ice was nearly 15,000 years old using a combination of traditional and new, novel techniques to date this ice core.
When they analyzed the ice, they found genetic codes for 33 viruses. Four of those viruses have already been identified by the scientific community. But at least 28 of them are novel. About half of them seemed to have survived at the time they were frozen not in spite of the ice, but because of it.
These viruses have signatures of genes that help them infect cells in cold environments—just surreal genetic signatures for how a virus is able to survive in extreme conditions.
Zhi-Ping Zhong et al, Glacier ice archives nearly 15,000-year-old microbes and phages, Microbiome (2021). DOI: 10.1186/s40168-021-01106-w
Surfing science: Dependent on weather, defined by the ocean
Serious wave chasers are by default atmospheric science junkies because there are few, if any, sports that are both dependent on an uncontrollable variable—the weather—and defined by a literal uneven playing field—the ocean.
Waves are created by the way the swells interact with the bottom contours of the ocean, called the break. Beach breaks—like the Olympic site at Tsurigasaki beach—happen because of sandbars, which can shift over time or due to storms.
Competitive surfing in a nutshell is about deciding which wave to take and what move or moves make the best use of what the ocean delivers. Surfers have to remain prepared and continuously observe the waves for their best guess of what wave they will get to ride.
Through the thin-film glass, researchers spot a new liquid phase
Research published in the Proceedings of the National Academy of Sciences describes a new type of liquid in thin films, which forms a high-density glass. Results generated in this study, conducted by researchers in Penn's Department of Chemistry, demonstrate how these glasses and other similar materials can be fabricated to be denser and more stable, providing a framework for developing new applications and devices through better design.
To make better glasses, researchers have used vapor deposition instead of cooling a liquid to produce a glass. In vapor deposition, a material is changed from a gas into a solid directly. While this method has allowed researchers to create denser types of bulk glasses, it was initially thought that thin glass films made using this method would still have the same liquid-like properties that would lead to degradation and instability.
After running all of the control experiments needed, the researchers were surprised to find that when using vapor deposition, they could access a different type of liquid, with a phase transition to the typical bulk liquid upon heating. A phase transition is when a material changes from from one state (gas, liquid, or solid) into another. "The two liquids have distinct structures, akin to graphene and diamond which are both solids made of carbon but exist in very different solid forms.
There are a lot of interesting properties that came out of nowhere, and nobody had thought that in thin films you would be able to see these phases. It's a new type of material.
Plastic accumulation in food may be underestimated
A new study has found plastic accumulation in foods may be underestimated. There is also concern these microplastics will carry potentially harmful bacteria such as E. coli,which are commonly found in coastal waters, up the food chain.
Researchers tested a theory that microplastics covered in a biofilm coating (much like natural algae) were more likely to be ingested by oysters than microplastics that were completely clean. Although the experiment was carried out on oysters under laboratory conditions, scientists believe similar results could be found in other edible marine species that also filter seawater for food.
Up until now, studies to test the impacts of microplastics on marine lifehave typically used clean, virgin microplastics. However, this is not representative of what happens to microplastics in the marine environment. Bacteria readily colonize microplastics that enter the ocean. In this study, published inScience of the Total Environment, scientists compared the uptake rates of clean microplastics versus microplastics with anE.colibiofilm coating. The results were worrying—oysters contained 10 times more microplastics when exposed to the biofilm coated beads. It is hypothesized that these coated MPs appeared to be more like food to the oysters, explaining their preferential ingestion over clean microplastics.
The scientists say the implications for the food chain are concerning. The ingestion of microplastics is not only bad for the oysters, but it affects human health too. The plastic does not break down in the marine animal and is consumed when we eat it.
The findings in this research give us further insight into the potential harm microplastics are having on the food chain. It demonstrates how we could be vastly underestimating the effect that microplastics currently have. It is clear that further study is urgently needed.
Monica Fabra et al, The plastic Trojan horse: Biofilms increase microplastic uptake in marine filter feeders impacting microbial transfer and organism health, Science of The Total Environment (2021). DOI: 10.1016/j.scitotenv.2021.149217
As experts continue to learn more about immune responses to COVID-19 and the effectiveness of vaccines, researchers.
indicates that the level of antibodies changes according to age groups, gender, symptoms, and time elapsed since vaccination. The findings are the latest from the researchers in a series of studies aimed at providing reliable measures on the effectiveness of COVID-19 vaccination. The new study examined the level of antibodies in over 26,000 blood samples taken from COVID-19 convalescents, as well as vaccinated and unvaccinated individuals. In vaccinated individuals, the researchers found differences between women and men in the concentration of antibodies in the blood relative to both age and gender.
In women, the level of antibodies begins to rise from the age of 51, and is higher than the levels found in men of similar age. This phenomenon may be related change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35, and may be related to changes in levels of testosterone and the effect on the immune system.
In young adults, a high concentration of antibodies generally signals a strong healthy functioning immune response, while in older demographics it typically indicates overreaction of the immune system associated with severe illness. In general, young adults were found to have a higher level of antibodies sustained for a longer period of time compared to older vaccinated persons. The findings further validate existing evidence that, depending on age, higher antibody count isn't necessarily equivalent to higher rates of recovery.
Furthermore, the study found that the immune response of vaccinated individuals (after two doses) is much stronger than that of people who have recovered from COVID-19. The findings show that vaccinated individuals have four times the level of antibodies compared to convalescents.
A Lagoon in Argentina Turned Bright Pink, But This Time The Reason Is Unnatural
A lagoon in Argentina's southern Patagonia region has turned bright pink in a striking, but frightful phenomenon experts and activists blame on pollution by a chemical used to preserve prawns for export.
The color is caused by sodium sulfite, an anti-bacterial product used in fish factories, whose waste is blamed for contaminating the Chubut river that feeds the Corfo lagoon and other water sources in the region, according to activists.
Residents have long complained of foul smells and other environmental issues around the river and lagoon.
Environmental engineer and virologist Federico Restrepo told AFP the coloration was due to sodium sulfite in fish waste, which by law, should be treated before being dumped.
The Universe has an average colour – and it’s called cosmic latte
In a 2002 study, astronomers found that the light coming from galaxies (and the stars within them) – alongside all the visible clouds of gas and dust in the Universe – when averaged, would produce an ivory colour very close to white. They named this colour ‘cosmic latte’.
The ‘beigeness’ of the Universe is because there are slightly more regions that produce red, yellow and green light than those that produce blue. Averaged over the entire sky, however, this beige colour is diluted and appears almost, but not entirely, black.
The body's so-called good cholesterol may be even better than we realize. New research from Washington University School of Medicine in St. Louis suggests that one type of high-density lipoprotein (HDL) has a previously unknown role in protecting the liver from injury. This HDL protects the liver by blocking inflammatory signals produced by common gut bacteria. The study was published July 23 in the journal Science. HDL is mostly known for mopping up cholesterol in the body and delivering it to the liver for disposal. But in the new study, the researchers identified a special type of HDL called HDL3 that, when produced by the intestine, blocks gut bacterial signals that cause liver inflammation. If not blocked, these bacterial signals travel from the intestine to the liver, where they activate immune cells that trigger an inflammatory state, which leads to liver damage. Even though HDL has been considered good cholesterol,’ drugs that increase overall HDL levels have fallen out of favor in recent years because of clinical trials that showed no benefit in cardiovascular disease. study suggests that raising levels of this specific type of HDL, and specifically raising it in the intestine, may hold promise for protecting against liver disease, which, like heart disease, also is a major chronic health problem.
Any sort of intestinal damage can impact how a group of microbes called Gram-negative bacteria can affect the body. Such microbes produce an inflammatory molecule called lipopolysaccharide that can travel to the liver via the portal vein. The portal vein is the major vessel that supplies blood to the liver, and it carries most nutrients to the liver after food is absorbed in the intestine. Substances from gut microbes may travel along with nutrients from food to activate immune cells that trigger inflammation. In this way, elements of the gut microbiome may drive liver disease, including fatty liver disease and liver fibrosis, in which the liver develops scar tissue.
Physicists Have Figured Out How We Could Make Antimatter Out of Light
A new study by scientists has demonstrated how researchers may be able to create an accelerating jet ofantimatterfrom light.
A team of physicists has shown that high-intensity lasers can be used to generate colliding gamma photons – the most energetic wavelengths of light – to produce electron-positron pairs. This, they say, could help us understand the environments around some of the Universe's most extreme objects: neutron stars.
The process of creating a matter-antimatter pair of particles – an electron and a positron – from photons is called theBreit-Wheeler process, and it's extremely difficult to achieve experimentally.
The probability of it taking place when two photons collide is very small. You need very high-energy photons, or gamma rays, and a lot of them, in order to maximize the chances of observation.
We don't yet have the capability to build agamma-ray laser, so the photon-photon Breit-Wheeler process currently remains experimentally unachieved. But a team of physicists led by Yutong He of the University of California, San Diego (UC San Diego) has proposed a new workaround that, according to their simulations, could actually work.
It consists of a plastic block, carved with a pattern of criss-crossing channels on the micrometer scale. Two powerful lasers, one on either side of the block, fire strong pulses at this target.
"When the laser pulses penetrate the sample, each of them accelerates a cloud of extremely fast electrons.
These two electron clouds then race toward each other with full force, interacting with the laser propagating in the opposite direction."
The resulting collision is so energetic that it produces a cloud of gamma photons. These gamma photons should collide with each other to produce electron-positron pairs, in accordance with Einstein's theory of general relativity.
Even more excitingly, this process should generate powerful magnetic fields thatcollimatethe positrons (rather than the electrons) into strongly accelerated, jet-shaped beams. In a distance of just 50 micrometers, the researchers found, the acceleration should increase the energy of the particles to one gigaelectronvolt.
Using a complex computer simulation, the researchers tested their model, and found that it should work, even when using less powerful lasers than previous proposals.
Not only would the collimation and acceleration of the positron beam improve the detection rate of the particles, but it bears a strong similarity to the powerful collimated particle jets beamed out by strongly magnetic, rapidly rotating neutron stars known as pulsars.
Scientists believe that processes that take place close to these stars could result in clouds of gamma radiation, similar to their proposed experiment.
Earth's 'vital signs' worsening as humanity's impact deepens
The global economy's business-as-usual approach to climate change has seen Earth's "vital signs" deteriorate to record levels, an influential group of scientists said recently, warning that several climate tipping points were now imminent.
The researchers, part of a group of more than 14,000 scientists who have signed on to an initiative declaring a worldwide climate emergency, said that governments had consistently failed to address the root cause of climate change: "the overexploitation of the Earth".
Of 31 "vital signs"—key metrics of planetary health that include greenhouse gas emissions, glacier thickness, sea-ice extent and deforestation—they found that 18 hit record highs or lows.
For example, despite a dip in pollution linked to the pandemic, levels of atmospheric CO2 and methane hit all-time highs in 2021.
Greenland and Antarctica both recently showed all-time low levels of ice mass, and glaciers are melting 31 percent faster than they did just 15 years ago, the authors said.
Both ocean heat and global sea levels set new records since 2019, and the annual loss rate of the Brazilian Amazon reached a 12-year high in 2020.
Echoing previous research, they said that forest degradation linked to fire, drought and logging was causing parts of the Brazilian Amazon to now act as a source of carbon, rather than absorb the gas from the atmosphere.
Livestock such as cows and sheep are now at record levels, numbering more than four billion and with a mass exceeding that of all humans and wild land mammals combined, they said.
We need to respond to the evidence that we are hitting climate tipping points with equally urgent action to decarbonise the global economy and start restoring instead of destroying nature, they stressed.
The researchers said there was "mounting evidence that we are nearing or have already crossed" a number of climate tipping points.
Dr. Krishna Kumari Challa
Human cells harness power of detergents to wipe out bacteria
This killer cleaner, a protein known as APOL3, thwarts infections by dissolving bacterial membranes. Researchers tested the protein on the food-poisoning bacteria Salmonella and other similar microbes.
The work offers new insight into how human cells defend themselves against infection, a process termed cell-autonomous immunity. While scientists knew that cells could attack bacterial membranes, this study uncovers what appears to be the first example of a protective intracellular protein with detergent-like action.
"A human apolipoprotein L with detergent-like activity kills intracellular pathogens" Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abf8113
https://phys.org/news/2021-07-human-cells-harness-power-detergents....
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Jul 16, 2021
Dr. Krishna Kumari Challa
Thinking without a brain: Studies in brainless slime molds reveal that they use physical cues to decide where to grow
Scientists have discovered that a brainless slime mold called Physarum polycephalum uses its body to sense mechanical cues in its surrounding environment, and performs computations similar to what we call "thinking" to decide in which direction to grow based on that information. Unlike previous studies with Physarum, these results were obtained without giving the organism any food or chemical signals to influence its behavior. The study is published in Advanced Materials.
Physarum is interesting because it doesn't have a brain but it can still perform a lot of the behaviours that we associate with thinking, like solving mazes, learning new things, and predicting events. Figuring out how proto-intelligent life manages to do this type of computation gives us more insight into the underpinnings of animal cognition and behavior, including our own.
The team's research demonstrated that this brainless creature was not simply growing toward the heaviest thing it could sense—it was making a calculated decision about where to grow based on the relative patterns of strain it detected in its environment.
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Slime molds are amoeba-like organisms that can grow to be up to several feet long, and help break down decomposing matter in the environment like rotting logs, mulch, and dead leaves. A single Physarum creature consists of a membrane containing many cellular nuclei floating within a shared cytoplasm, creating a structure called a syncytium. Physarum moves by shuttling its watery cytoplasm back and forth throughout the entire length of its body in regular waves, a unique process known as shuttle streaming. With most animals, we can't see what's changing inside the brain as the animal makes decisions. Physarum offers a really exciting scientific opportunity because we can observe its decisions about where to move in real-time by watching how its shuttle streaming behavior changes.
While previous studies have shown that Physarum moves in response to chemicals and light, Murugan and her team wanted to know if it could make decisions about where to move based on physical cues in its environment alone.
The researchers placed Physarum specimens in the center of petri dishes coated with a semi-flexible agar gel and placed either one or three small glass discs next to each other atop the gel on opposite sides of each dish. They then allowed the organisms to grow freely in the dark over the course of 24 hours, and tracked their growth patterns. For the first 12 to 14 hours, the Physarum grew outwards evenly in all directions; after that, however, the specimens extended a long branch that grew directly over the surface of the gel toward the three-disc region 70% of the time. Remarkably, the Physarum chose to grow toward the greater mass without first physically exploring the area to confirm that it did indeed contain the larger object.
Jul 16, 2021
Dr. Krishna Kumari Challa
Part 2:
The researchers experimented with several variables to see how they impacted Physarum's growth decisions, and noticed something unusual: when they stacked the same three discs on top of each other, the organism seemed to lose its ability to distinguish between the three discs and the single disc. It grew toward both sides of the dish at roughly equal rates, despite the fact that the three stacked discs still had greater mass. Clearly, Physarum was using another factor beyond mass to decide where to grow.
To figure out the missing piece of the puzzle, the scientists used computer modeling to create a simulation of their experiment to explore how changing the mass of the discs would impact the amount of stress (force) and strain (deformation) applied to the semi-flexible gel and the attached growing Physarum. As they expected, larger masses increased the amount of strain, but the simulation revealed that the strain patterns the masses produced changed, depending on the arrangement of the discs.
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But how was it detecting these strain patterns? The scientists suspected it had to do with Physarum's ability to rhythmically contract and tug on its substrate, because the pulsing and sensing of the resultant changes in substrate deformation allows the organism to gain information about its surroundings.
Advanced Materials (2021). DOI: 10.1002/adma.202008161
https://phys.org/news/2021-07-brain-brainless-slime-molds-reveal.ht...
Jul 16, 2021
Dr. Krishna Kumari Challa
Researchers create snake-venom-derived 'super glue' that stops bleeding in seconds
This super glue is based on a new discovery on a blood clotting enzyme called reptilase or batroxobin found in the venom of lancehead snakes (Bothrops atrox), which are amongst the most poisonous snakes in South America.
Taking advantage of this clotting property, researchers designed a body tissue adhesive that incorporates the special enzyme into a modified gelatin that can be packaged into a small tube for easy, and potentially life-saving, application.
During trauma, injury and emergency bleeding, this 'super glue' can be applied by simply squeezing the tube and shining a visible light, such as a laser pointer, over it for few seconds. Even a smartphone flashlight will do the job.
Compared to clinical fibrin glue, considered the industry gold standard for clinical and field surgeons, the new tissue sealant has 10 times the adhesive strength to resist detachment or washout due to bleeding. The blood clotting time is also much shorter, cutting it in half from 90 seconds for fibrin glue to 45 seconds for the new snake venom "super glue."
This new biotechnology translates to less blood loss and more life-saving. The super-sealant was tested in models for deep skin cuts, ruptured aortae, and severely injured livers—all considered as major bleeding situations.
Yicheng Guo et al, Snake extract–laden hemostatic bioadhesive gel cross-linked by visible light, Science Advances (2021). DOI: 10.1126/sciadv.abf9635
https://phys.org/news/2021-07-snake-venom-derived-super-seconds-vis...
Jul 16, 2021
Dr. Krishna Kumari Challa
Researchers confirm we may never know how many species have inhabit...
Professors in Syracuse University's College of Arts and Sciences explored whether or not the scientific community will ever be able to settle on a 'total number' of species of living vertebrates, which could help with species preservation. By knowing what's out there, researchers argue that they can prioritize places and groups on which to concentrate conservation efforts.
Bruce H Wilkinson et al, Estimating vertebrate biodiversity using the tempo of taxonomy – a view from Hubbert's peak, Biological Journal of the Linnean Society (2021). DOI: 10.1093/biolinnean/blab080
Jul 16, 2021
Dr. Krishna Kumari Challa
‘Super-antibodies’ could curb COVID-19 and help avert future pandemics
Companies are designing next-generation antibodies modeled on those taken from unique individuals whose immune systems can neutralize any COVID-19 variant—and related coronaviruses, too.
A new generation of designer antibodies could help to treat a wide range of SARS-CoV-2 variants — and future coronaviruses with pandemic potential. ‘Super-antibodies’ are modelled on antibodies taken from rare individuals whose immune systems can neutralize any SARS-CoV-2 variant and related coronaviruses.
https://www.nature.com/articles/s41587-021-00980-x?utm_source=Natur...
Jul 16, 2021
Dr. Krishna Kumari Challa
Jul 17, 2021
Dr. Krishna Kumari Challa
Just 7% of our DNA is unique to modern humans, study shows
What makes humans unique? Scientists have taken another step toward solving an enduring mystery with a new tool that may allow for more precise comparisons between the DNA of modern humans and that of our extinct ancestors.
Just 7% of our genome is uniquely shared with other humans, and not shared by other early ancestors, according to a study published Friday in the journal Science Advances.
That's a pretty small percentage. This kind of finding is why scientists are turning away from thinking that we humans are so vastly different from Neanderthals.
The research draws upon DNA extracted from fossil remains of now-extinct Neanderthals and Denisovans dating back to around 40,000 or 50,000 years ago, as well as from 279 modern people from around the world.
Scientists already know that modern people share some DNA with Neanderthals, but different people share different parts of the genome. One goal of the new research was to identify the genes that are exclusive to modern humans.
It's a difficult statistical problem, and the researchers developed a valuable tool that takes account of missing data in the ancient genomes.
The researchers also found that an even smaller fraction of our genome—just 1.5%—is both unique to our species and shared among all people alive today. Those slivers of DNA may hold the most significant clues as to what truly distinguishes modern human beings.
Scientists now can tell those regions of the genome are highly enriched for genes that have to do with neural development and brain function.
Nathan K. Schaefer et al, An ancestral recombination graph of human, Neanderthal, and Denisovan genomes, Science Advances (2021). DOI: 10.1126/sciadv.abc0776
https://phys.org/news/2021-07-dna-unique-modern-humans.html?utm_sou...
Jul 17, 2021
Dr. Krishna Kumari Challa
Common medication used to reduce cholesterol levels may reduce COVID-19 severity
In a new study, researchers have confirmed that patients taking statin medications had a 41 percent lower risk of in-hospital death from COVID-19. The findings were published July 15, 2021 in PLOS ONE.
Statins are commonly used to reduce blood cholesterol levels by blocking liver enzymes responsible for making cholesterol. They are widely prescribed.
When faced with this virus at the beginning of the pandemic, there was a lot of speculation surrounding certain medications that affect the body's ACE2 receptor, including statins, and whether they may influence COVID-19 risk. At the time, scientists thought that statins may inhibit SARS-CoV-2 infection through their known anti-inflammatory effects and binding capabilities, which could potentially stop progression of the virus.
Researchers now analyzed anonymized medical records of 10,541 patients admitted for COVID-19 over a nine-month period, January through September 2020, at 104 different hospitals.
From this data, they performed more advanced analyses as they attempted to control for coexisting medical conditions, socioeconomic status and hospital factors. In doing so, they confirmed their prior findings that statins are associated with a reduced risk of death from COVID-19 among patients hospitalized for COVID-19.
It appears most of the benefit is among patients with good medical reasons to be taking statins, such as a history of cardiovascular disease or high blood pressure. According to the research team, the use of statins or an anti-hypertension medication was associated with a 32 percent lower risk of death among COVID-19 inpatients with a history of cardiovascular disease or hypertension.
In the study, statistical matching techniques were used to compare outcomes for patients who used statins or an anti-hypertension medication with similar patients who did not.
The ACE2 receptor—the regulatory target of statins—helps control blood pressure. In 2020, it was discovered that SARS-CoV-2 virus primarily uses the same receptor to enter lung cells.
According to researchers, statins and anti-hypertension medications stabilize the underlying diseases for which they are prescribed, making patients more likely to recover from COVID-19.
As with any observational study, researchers cannot say for certain that the associations they describe between statin use and reduced severity of COVID-19 infection are definitely due to the statins themselves; however, they can now say with very strong evidence that they may play a role in substantially lowering a patient's risk of death from COVID-19.
Lori B. Daniels et al, Relation of prior statin and anti-hypertensive use to severity of disease among patients hospitalized with COVID-19: Findings from the American Heart Association's COVID-19 Cardiovascular Disease Registry, PLOS ONE (2021). DOI: 10.1371/journal.pone.0254635
https://medicalxpress.com/news/2021-07-common-medication-cholestero...
Jul 17, 2021
Dr. Krishna Kumari Challa
Antibiotics in early life could affect brain development
Antibiotic exposure early in life could alter human brain development in areas responsible for cognitive and emotional functions, according to some researchers. The laboratory study, published in the journal iScience, suggests that penicillin changes the microbiome the trillions of beneficial microorganisms that live in and on our bodies as well as gene expression, which allows cells to respond to its changing environment, in key areas of the developing brain. The findings suggest reducing widespread antibiotic use or using alternatives when possible to prevent neurodevelopment problems. Penicillin and related medicines (like ampicillin and amoxicillin) are the most widely used antibiotics in children worldwide.
Previous work has shown that exposing young animals to antibiotics changes their metabolism and immunity. The third important development in early life involves the brain. This study is preliminary but shows a correlation between altering the microbiome and changes in the brain that should be further explored.
The study compared mice that were exposed to low-dose penicillin in utero or immediately after birth to those that were not exposed. They found that mice given penicillin experienced substantial changes in their intestinal microbiota and had altered gene expression in the frontal cortex and amygdala, two key areas in the brain responsible for the development of memory as well as fear and stress responses.
A growing body of evidence links phenomena in the intestinal tract with signaling to the brain, a field of study known as the “gut-brain-axis.” If this pathway is disturbed, it can lead to permanent altering of the brain’s structure and function and possibly lead to neuropsychiatric or neurodegenerative disorders in later childhood or adulthood.
https://researchnews.cc/news/7831/Antibiotics-in-early-life-could-a...
Jul 17, 2021
Dr. Krishna Kumari Challa
The world's thinnest technology-only two atoms thick
Jul 17, 2021
Dr. Krishna Kumari Challa
Long COVID Has Over 200 Symptoms!
A new study has identified 203 different long COVID symptoms across 10 different organ systems in the body, highlighting just how widespread and varied the affliction is and how it can interfere with many different aspects of daily life.
With a total of 3,762 people quizzed across 56 countries, the international study is the biggest and most comprehensive look yet at how 'long haulers' continue to have problems way beyond the normal timescale of COVID-19.
The most commonly reported symptoms were fatigue, post-exertional malaise (symptoms getting worse after physical or mental effort), and cognitive dysfunction or 'brain fog'. Other symptoms included visual hallucinations, tremors, sexual dysfunction, memory loss, and diarrhea – a whole range of physical and cognitive health issues.
On average, participants reported 55.9 symptoms each, across 9.1 organ systems. Of the 3,762 respondents with long COVID, 2,454 had experienced symptoms for at least six months. All that takes a toll: 45.2 percent of participants said they had reduced their working hours, while 22.3 percent were not working at all at the time of the survey.
"By seven months, many patients have not yet recovered (mainly from systemic and neurological/cognitive symptoms), have not returned to previous levels of work, and continue to experience significant symptom burden," write the researchers in their published paper.
https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(21)00299-6/fulltext
Jul 18, 2021
Dr. Krishna Kumari Challa
Common COVID-19 antibiotic no more effective than placebo
A new study has found that the antibiotic azithromycin was no more effective than a placebo in preventing symptoms of COVID-19 among non-hospitalized patients, and may increase their chance of hospitalization, despite widespread prescription of the antibiotic for the disease.
https://jamanetwork.com/journals/jama/fullarticle/2782166
https://researchnews.cc/news/7855/Common-COVID-19-antibiotic-no-mor...
These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection.
Azithromycin, a broad-spectrum antibiotic, is widely prescribed as a treatment for COVID-19 in the United States and the rest of the world. The hypothesis is that it has anti-inflammatory properties that may help prevent progression if treated early in the disease. But this was found to be untrue.
The study was published in the Journal of the American Medical Association
Jul 18, 2021
Dr. Krishna Kumari Challa
Global satellite data shows clouds will amplify global heating
A new approach to analyze satellite measurements of Earth's cloud cover reveals that clouds are very likely to enhance global heating.
The research is the strongest evidence yet that clouds will amplify global heating over the long term, further exacerbating climate change.
It also suggest that at double atmospheric carbon dioxide (CO2) concentrations above pre-industrial levels, the climate is unlikely to warm below 2°C, and is more likely on average to warm more than 3°C.
Pre-industrial CO2 levels were around 280 ppm (parts per million), but current levels are approaching 420 ppm, and could approach double the pre-industrial amount by mid-century if significant emissions cuts are not made. The amount of climate warming predicted from a doubling of pre-industrial CO2 levels is known as the 'climate sensitivity' - a measure of how strongly our climate will react to such a change.
The largest uncertainty in climate sensitivity predictions is the influence of clouds, and how they may change in the future. This is because clouds, depending on properties such as their density and height in the atmosphere, can either enhance or dampen warming.
Low clouds tend to have a cooling effect, as they block the sun from reaching the ground. High clouds, however, have a warming effect, as while they let solar energy reach the ground, the energy emitted back from the Earth is different. This energy can be trapped by the clouds, enhancing the greenhouse effect. Therefore, the type and amount of cloud a warming world will produce impacts further warming potential.
Paulo Ceppi el al., "Observational evidence that cloud feedback amplifies global warming," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2026290118
https://phys.org/news/2021-07-global-satellite-clouds-amplify.html?...
Jul 20, 2021
Dr. Krishna Kumari Challa
Massive DNA 'borg' structures perplex scientists
These extra-long DNA strands, which the scientists named in honour of the aliens, join a diverse collection of genetic structures — circular plasmids, for example — known as extrachromosomal elements (ECEs). Most microbes have one or two chromosomes that encode their primary genetic blueprint. But they can host, and often share between them, many distinct ECEs. These carry non-essential but useful genes, such as those for antibiotic resistance.
Borgs are a previously unknown, unique and “absolutely fascinating” type of ECE. Borgs are DNA structures “not like any that’s been seen before”. Most scientists agree that the find is exciting, but some have questioned whether Borgs really are unique, noting similarities between them and other large ECEs.
Their vast size, ranging between more than 600,000 and about 1 million DNA base pairs in length, is one feature that distinguishes Borgs from many other ECEs. In fact, Borgs are so huge that they are up to one-third of the length of the main chromosome in their host microbes.
More here: https://www.nature.com/articles/d41586-021-01947-3?utm_source=Natur...
Jul 20, 2021
Dr. Krishna Kumari Challa
SCI-COM:
An exciting career pathway for connecting Science to the Masses
CSIR‐NISCAIR offers doctoral degree and post graduate courses in Science & Technology Communication
http://niscair.res.in/researchandeducation/acsir
Jul 20, 2021
Dr. Krishna Kumari Challa
NASA Lucy mission's message to the future
In the 1970s four spacecraft began their one-way trips out of our Solar System. As the first human-built objects to ever venture into interstellar space, NASA chose to place plaques on Pioneer 10 and 11 and golden records on Voyager 1 and 2 spacecraft to serve as messages to any alien spacefarers that may someday encounter these spacecraft. Continuing this legacy, NASA's Lucy spacecraft will carry a similar plaque. However, because Lucy will not be venturing outside of our Solar System, Lucy's plaque is a time-capsule featuring messages to our descendants.
Jul 20, 2021
Dr. Krishna Kumari Challa
No more broken mobile screens: Bengal researchers develop self-healing material
The research has also made it to the coveted Science journal published by the American Association for the Advancement of Science. The scientists claimed that the highly crystalline materials, when broken into pieces, can self-heal and re-join in a matter of a second, and repair themselves so precisely that they become indistinguishable from the undisturbed materials.
The scientists hope that the discovery can spark a revolution in the field of digital technology, such as broken screens of gadgets and other new-age technologies.
The researchers said materials applied in technologies undergo mechanical impacts which often make the devices irreparable. The idea prompted the team to delve deep in search of self-repairing materials to enhance the longevity of the devices without external intervention.
Researchers developed a new class of solid materials that with a head-to-tail (positive end-to-negative end) polar arrangement in the crystalline state generates opposite electrical potentials at the fractured surfaces. These charges allow instant recombination and self-repair of the broken crystals without any external help. The scientists said that during the repair, fractured pieces travel with a honeybee wing-like motion with acceleration comparable to diesel cars.
Another team from IISER used a custom-designed state-of-the-art polarisation microscopic system to probe and quantify the structural order of the piezoelectric self-healing organic crystals with nanometer-scale spatial resolution.
The scientists said that these crystals, which belong to a general class of piezoelectric materials, can generate electricity under pressure, which in turn can heal and retain their crystalline nature which is important for many applications.
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https://www.hindustantimes.com/science/no-more-broken-mobile-screen...
Jul 20, 2021
Dr. Krishna Kumari Challa
Common Medication Used to Reduce Cholesterol Levels May Reduce COVI... (UCSD Health, 7/15/21)
Common cholesterol drugs statins may lower death risk from COVID-19 (Seeking Alpha, 7/19/21)
Jul 20, 2021
Dr. Krishna Kumari Challa
Scientists create world's thinnest magnet
The development of an ultrathin magnet that operates at room temperature could lead to new applications in computing and electronics—such as high-density, compact spintronic memory devices—and new tools for the study of quantum physics.
The ultrathin magnet, which was recently reported in the journal Nature Communications , could make big advances in next-gen memories, computing, spintronics, and quantum physics.
This discovery is exciting because it not only makes 2-D magnetismpossible at room temperature, but it also uncovers a new mechanism to realize 2-D magnetic materials.
zinc oxide's free electrons could act as an intermediary that ensures the magnetic cobalt atoms in the new 2-D device continue pointing in the same direction—and thus stay magnetic—even when the host, in this case the semiconductor zinc oxide, is a nonmagnetic material.
Rui Chen et al, Tunable room-temperature ferromagnetism in Co-doped two-dimensional van der Waals ZnO, Nature Communications (2021). DOI: 10.1038/s41467-021-24247-w
https://phys.org/news/2021-07-scientists-world-thinnest-magnet.html...
Jul 21, 2021
Dr. Krishna Kumari Challa
The Standard Model
Jul 21, 2021
Dr. Krishna Kumari Challa
Quantum Computers, Explained With Quantum Physics
Jul 21, 2021
Dr. Krishna Kumari Challa
Microbially produced fibers: Stronger than steel, tougher than Kevlar
Spider silk is said to be one of the strongest, toughest materials on the Earth. Now engineers have designed amyloid silk hybrid proteins and produced them in engineered bacteria. The resulting fibers are stronger and tougher than some natural spider silks.
The artificial silk—dubbed "polymeric amyloid" fiber—was not technically produced by researchers, but by bacteria that were genetically engineered in the lab.
Jingyao Li et al, Microbially Synthesized Polymeric Amyloid Fiber Promotes β-Nanocrystal Formation and Displays Gigapascal Tensile Strength, ACS Nano (2021). DOI: 10.1021/acsnano.1c02944
https://phys.org/news/2021-07-microbially-fibers-stronger-steel-tou...
Jul 22, 2021
Dr. Krishna Kumari Challa
Study finds calcium precisely directs blood flow in the brain
Unlike the rest of the body, there is not enough real estate in the brain for stored energy. Instead, the brain relies on the hundreds of miles of blood vessels within it to supply fresh energy via the blood. Yet, how the brain expresses a need for more energy during increased activity and then directs its blood supply to specific hot spots was, until now, poorly understood.
Now, researchers have shown how the brain communicates to blood vessels when in need of energy, and how these blood vessels respond by relaxing or constricting to direct blood flow to specific brain regions.
If the brain does not get blood to where it needs it when it needs it, the neurons become stressed, and over time they deteriorate ultimately leading to cognitive decline and memory problems.
Large arteries feed medium-sized vessels known as arterioles that then feed even tinier capillaries—so small that only a single blood cell can pass through at once. In a 2017 Nature Neuroscience paper, the researchers showed that electrical pulses coursing through the capillaries direct blood flow from the medium-sized arterioles supplying large regions of the brain. For this latest paper, the team studied the fine-tuning of blood as it flows through the capillaries to precisely regulate energy supply to tiny regions in the brain.
There seem to be two mechanisms working in tandem to ensure that energy in the form of blood makes it to specific regions of the brain: one broad and the other precise. The first electrical mechanism is like a crude sledgehammer approach to get more blood to the general vicinity of the increased brain activity by controlling the medium-sized arterioles, and then capillary calcium signals ensure exquisite fine-tuning to make sure the blood gets to exactly the right place at the right time through the tiny capillaries.
"Local IP3 receptor–mediated Ca2+ signals compound to direct blood flow in brain capillaries" Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abh0101
https://medicalxpress.com/news/2021-07-calcium-precisely-blood-brai...
Jul 22, 2021
Dr. Krishna Kumari Challa
Rounding errors could make certain stopwatches pick wrong race winners
As the Summer Olympics draw near, the world will shift its focus to photo finishes and races determined by mere fractions of a second. Obtaining such split-second measurements relies on faultlessly rounding a raw time recorded by a stopwatch or electronic timing system to a submitted time.
Researchers now found certain stopwatches commit rounding errors when converting raw times to final submitted times. They outline a series of computer simulations based on procedures for converting raw race times for display.
These researchers were inspired when they encountered the issue firsthand while volunteering at a swim meet. While helping input times into the computer, they noticed a large portion of times they inputted were rounded to either the closest half-second or full second.
Later, when the frequencies of the digit pairs were plotted, a distinct pattern emerged. They discovered that the distribution of digit pairs was statistically inconsistent with the hypothesis that each digit pair was equally likely, as one would expect from stopwatches.
Stopwatches and electronic timing systems use quartz oscillators to measure time intervals, with each oscillation calculated as 0.0001 seconds. These times are then processed for display to 0.01 seconds, for example, to the public at a sporting venue.
When the researchers processed raw times through the standard display routine, the uniform distribution disappeared. Most times were correctly displayed.
Where rounding errors occurred, they usually resulted in changes of one one-hundredth of a second. One raw time of 28.3194 was converted to a displayed time of 28.21.
The researchers collected more than 30,000 race times from swimming competitions and will investigate if anomalous timing patterns appear in the collection, which would suggest the potential for rounding errors in major sporting events.
David A. Faux et al, The floating point: Rounding error in timing devices, American Journal of Physics (2021). DOI: 10.1119/10.0003919
https://phys.org/news/2021-07-rounding-errors-stopwatches-wrong-win...
Jul 22, 2021
Dr. Krishna Kumari Challa
Fire tornadoes explained
The roaring Bootleg Fire burning up swaths of southwestern Oregon is the nation's largest wildfire so far this year and intense enough that it's triggering weather phenomena, including lightning, massive columns of smoke and ash clouds reaching high into the atmosphere, and even the possibility of a "fire tornado." Loretta Mickley, senior research fellow in chemistry-climate interactions at the Harvard John A. Paulson School of Engineering and Applied Sciences, has examined the interaction of wildfires and climate and published research on the likelihood that the wildfires will grow larger and more frequent in the years to come. The Gazette spoke to Mickley to better understand the causes, dangers, and expectations for the future.
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Planetary shields will buckle under stellar winds from their dying ...
Any life identified on planets orbiting white dwarf stars almost certainly evolved after the star's death, says a new study led by the University of Warwick that reveals the consequences of the intense and furious stellar winds that will batter a planet as its star is dying. The research is published in Monthly Notices of the Royal Astronomical Society, and lead author Dr. Dimitri Veras will present it today (21 July) at the online National Astronomy Meeting (NAM 2021).
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Windows 10/11 vulnerability exposes admin passwords to local users
A Twitter user has found and made public a Windows 10/11 vulnerability that exposes admin passwords to local users who can then escalate their privileges up to admin, giving them total system access. As he notes on his posts, he found that Windows Security Account Manager (SAM) data could be read by users with very limited privileges, giving them access to admin passwords. Microsoft apparently caught wind of the vulnerability and posted an Executive Summary of the issue on its Security Vulnerability page.
Jul 22, 2021
Dr. Krishna Kumari Challa
Phage-based COVID vaccines
Jul 22, 2021
Dr. Krishna Kumari Challa
RNA breakthrough creates crops that can grow 50% more potatoes, rice
Manipulating RNA can allow plants to yield dramatically more crops, as well as increasing drought tolerance, announced a group of scientists.
In initial tests, adding a gene encoding for a protein called FTO to both rice and potato plants increased their yield by 50% in field tests. The plants grew significantly larger, produced longer root systems and were better able to tolerate drought stress. Analysis also showed that the plants had increased their rate of photosynthesis.
The change really is dramatic. What's more, it worked with almost every type of plant scientists tried it with so far, and it's a very simple modification to make.
We know that the RNA molecule reads DNA, then makes proteins to carry out tasks. But RNA doesn't simply read the DNA blueprint and carry it out blindly; the cell itself can also regulate which parts of the blueprint get expressed. It does so by placing chemical markers onto RNA to modulate which proteins are made and how many. Scientists realized that this had major implications for biology.
They focused on a protein called FTO, the first known protein that erases chemical marks on RNA. The scientists knew it worked on RNA to affect cell growth in humans and other animals, so they tried inserting the gene for it into rice plants—and then watched in amazement as the plants took off.
The rice plants grew three times more rice under laboratory conditions. When they tried it out in real field tests, the plants grew 50% more mass and yielded 50% more rice. They grew longer roots, photosynthesized more efficiently, and could better withstand stress from drought.
The scientists repeated the experiments with potato plants, which are part of a completely different family. The results were the same.
That suggested a degree of universality that was extremely exciting.
RNA demethylation increases the yield and biomass of rice and potato plants in field trials, Nature Biotechnology, DOI: 10.1038/s41587-021-00982-9 , www.nature.com/articles/s41587-021-00982-9
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It took the scientists longer to begin to understand how this was happening. Further experiments showed that FTO started working early in the plant's development, boosting the total amount of biomass it produced.
The scientists think that FTO controls a process known as m6A, which is a key modification of RNA. In this scenario, FTO works by erasing m6A RNA to muffle some of the signals that tell plants to slow down and reduce growth.
https://phys.org/news/2021-07-rna-breakthrough-crops-potatoes-rice....
Jul 23, 2021
Dr. Krishna Kumari Challa
How newborn mammals dream the world they're entering
As a newborn mammal opens its eyes for the first time, it can already make visual sense of the world around it. But how does this happen before they have experienced sight?
A new study suggests that, in a sense, mammals dream about the world they are about to experience before they are even born.
Scientists describe the process as waves of activity that emanate from the neonatal retina in mice before their eyes ever open.
This activity disappears soon after birth and is replaced by a more mature network of neural transmissions of visual stimuli to the brain, where information is further encoded and stored.
But how do the circuits form that allow us to perceive motion and navigate the world? It turns out we are born capable of many of these behaviors, at least in rudimentary form.
Scientists explored the origins of these waves of activity. Imaging the brains of mice soon after birth but before their eyes opened, the Yale team found that these retinal waves flow in a pattern that mimics the activity that would occur if the animal were moving forward through the environment.
This early dream-like activity makes evolutionary sense because it allows a mouse to anticipate what it will experience after opening its eyes, and be prepared to respond immediately to environmental threats.
They also investigated the cells and circuits responsible for propagating the retinal waves that mimic forward motion in neonatal mice. They found that blocking the function of starburst amacrine cells, which are cells in the retina that release neurotransmitters, prevents the waves from flowing in the direction that mimics forward motion. This in turn impairs the development of the mouse's ability to respond to visual motion after birth.
Intriguingly, within the adult retina of the mouse these same cells play a crucial role in a more sophisticated motion detection circuit that allows them to respond to environmental cues.
Mice, of course, differ from humans in their ability to quickly navigate their environment soon after birth. However, human babies are also able to immediately detect objects and identify motion, such as a finger moving across their field of vision, suggesting that their visual system was also primed before birth.
These brain circuits are self-organized at birth and some of the early teaching is already done. It's like dreaming about what you are going to see before you even open your eyes.
X. Ge el al., "Retinal waves prime visual motion detection by simulating future optic flow," Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abd0830
https://phys.org/news/2021-07-eyes-wide-newborn-mammals-world.html?...
Jul 23, 2021
Dr. Krishna Kumari Challa
Why delta variant is highly transmissible
In a preprint posted 12 July1, the researchers report that virus was first detectable in people with the Delta variant four days after exposure,compared with an average of six days among people with the original strain, suggesting that Delta replicates much faster. Individuals infected with Delta also had viral loads up to 1,260 times higher than those in people infected with the original strain.
The combination of a high number of viruses and a short incubation period makes sense as an explanation for Delta’s heightened transmissibility.
The sheer amount of virus in the respiratory tract means that superspreading events are likely to infect even more people, and that people might begin spreading the virus earlier after they become infected.
And the short incubation makes contact tracing more difficult in some countries.
Putting it all together, Delta’s really difficult to stop.
The highly contagious Delta variant of Covid-19 is expected to become the dominant strain of the virus over the coming months, according to the World Health Organization.
https://www.medrxiv.org/content/10.1101/2021.07.07.21260122v1
https://www.nature.com/articles/d41586-021-01986-w?utm_source=Natur...
Jul 23, 2021
Dr. Krishna Kumari Challa
The science of underwater swimming: How staying submerged gives Olympians the winning edge
To win swimming gold in Tokyo, swimmers not only have to generate incredible power with their arms and legs to propel themselves through the water; they also have to overcome the relentless pull of the water's drag while doing so.
Without being able to don special low-drag suits or use technologies to help them fly over the water, how can swimmers make the effect of the water's drag as small as possible?
The best athletes in this year's Olympics will do it by swimming under, rather than on top of, the water—at least as far as the rules allow.
Water is much denser than air, so you might assume swimmers would benefit from using a technique that allows them to sit high in the water, with as much of their body out of the water as possible.
But there are two problems with this strategy.
First, it costs energy to produce the forces needed to lift the body, which would be better spent propelling the swimmer forwards towards the finishing wall.
Second, when we travel on the water's surface we waste energy making waves. During fast swimming, such as in the sprint freestyle events or during starts and turns (where speeds exceed 2 meters per second, or about 7 kilometers per hour), wave generation slows the swimmer down more than any other factor. Reducing wave formation is therefore vital to swimming success.
Waves are produced as the pressure exerted by the swimmer on the water forces the water upwards and out of their path. Other pressure changes around the swimmer's body also cause waves to form behind them, and sometimes to the side.
The energy required to generate waves comes from the swimmer themselves, so a lot of the power generated by the swimmer's muscles is used in wave generation rather than moving the swimmer forwards.
But waves aren't formed when we (or fish, dolphins or whales) swim under the water, because waves only form when an object (like us) moves at the boundary between two fluids of different densities, such as water and air during swimming. And this fact hints at an intriguing solution to the drag issue.
Here, the swimmer propels themselves underwater by undulating the lower body in a wave-like manner while maintaining a rigid and streamlined upper body position with arms stretched overhead.
The amplitude of the lower body undulation increases from the hips to the feet so the "wave" produced by the body is much greater down towards the feet, creating a whip-like effect. This pushes water rapidly backwards, propelling the swimmer forwards according to Newton's law of action and reaction.
Although some aspects of underwater swimming is banned, the benefits of improving the underwater undulation technique are so great that swimmers still spend hours each week in training improving this part of the race.
https://theconversation.com/the-science-of-underwater-swimming-how-...
Jul 24, 2021
Dr. Krishna Kumari Challa
Cockatoos have learned to open curb-side bins — and it has global significance
Jul 25, 2021
Dr. Krishna Kumari Challa
In a study published in Molecular Psychiatry, a research team show that changes in the extracellular matrix of the brain scaffolding around nerve cells lead to loss of memory with ageing, but that it is possible to reverse these using genetic treatments. Recent evidence has emerged of the role of perineuronal nets (PNNs) in neuroplasticity the ability of the brain to learn and adapt and to make memories. PNNs are cartilage-like structures that mostly surround inhibitory neurons in the brain. Their main function is to control the level of plasticity in the brain. They appear at around five years old in humans, and turn off the period of enhanced plasticity during which the connections in the brain are optimised. Then, plasticity is partially turned off, making the brain more efficient but less plastic. PNNs contain compounds known as chondroitin sulphates. Some of these, such as chondroitin 4-sulphate, inhibit the action of the networks, inhibiting neuroplasticity; others, such as chondroitin 6-sulphate, promote neuroplasticity. As we age, the balance of these compounds changes, and as levels of chondroitin 6-sulphate decrease, so our ability to learn and form new memories changes, leading to age-related memory decline.
They investigated whether manipulating the chondroitin sulphate composition of the PNNs might restore neuroplasticity and alleviate age-related memory deficits.
To do this, the team looked at 20-month old mice – considered very old – and using a suite of tests showed that the mice exhibited deficits in their memory compared to six-month old mice.
For example, one test involved seeing whether mice recognised an object. The mouse was placed at the start of a Y-shaped maze and left to explore two identical objects at the end of the two arms. After a short while, the mouse was once again placed in the maze, but this time one arm contained a new object, while the other contained a copy of the repeated object. The researchers measured the amount of time the mouse spent exploring each object to see whether it had remembered the object from the previous task. The older mice were much less likely to remember the object.
The team treated the ageing mice using a ‘viral vector’, a virus capable of reconstituting the amount of 6-sulphate chondroitin sulphates to the PNNs and found that this completely restored memory in the older mice, to a level similar to that seen in the younger mice.
Jul 25, 2021
Dr. Krishna Kumari Challa
How Carbon Capture Works
Jul 25, 2021
Dr. Krishna Kumari Challa
‘Ancient RNA virus epidemics occurred frequently during human evolution’
https://www.sciencedirect.com/science/article/pii/S0960982221007946#!
https://www.medicalnewstoday.com/articles/ancient-rna-virus-epidemi...
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Jul 25, 2021
Dr. Krishna Kumari Challa
15,000-year-old viruses discovered in Tibetan glacier ice
Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.
The findings, published today in the journal Microbiome, could help scientists understand how viruses have evolved over centuries. For this study, the scientists also created a new, ultra-clean method of analyzing microbes and viruses in ice without contaminating it.
The researchers analyzed ice cores taken in 2015 from the Guliya ice cap in western China. The cores are collected at high altitudes—the summit of Guliya, where this ice originated, is 22,000 feet above sea level. The ice cores contain layers of ice that accumulate year after year, trapping whatever was in the atmosphere around them at the time each layer froze. Those layers create a timeline of sorts, which scientists have used to understand more about climate change, microbes, viruses and gasses throughout history.
Researchers determined that the ice was nearly 15,000 years old using a combination of traditional and new, novel techniques to date this ice core.
When they analyzed the ice, they found genetic codes for 33 viruses. Four of those viruses have already been identified by the scientific community. But at least 28 of them are novel. About half of them seemed to have survived at the time they were frozen not in spite of the ice, but because of it.
These viruses have signatures of genes that help them infect cells in cold environments—just surreal genetic signatures for how a virus is able to survive in extreme conditions.
Zhi-Ping Zhong et al, Glacier ice archives nearly 15,000-year-old microbes and phages, Microbiome (2021). DOI: 10.1186/s40168-021-01106-w
https://phys.org/news/2021-07-year-old-viruses-tibetan-glacier-ice....
Jul 26, 2021
Dr. Krishna Kumari Challa
Surfing science: Dependent on weather, defined by the ocean
Serious wave chasers are by default atmospheric science junkies because there are few, if any, sports that are both dependent on an uncontrollable variable—the weather—and defined by a literal uneven playing field—the ocean.
Waves are created by the way the swells interact with the bottom contours of the ocean, called the break. Beach breaks—like the Olympic site at Tsurigasaki beach—happen because of sandbars, which can shift over time or due to storms.
Competitive surfing in a nutshell is about deciding which wave to take and what move or moves make the best use of what the ocean delivers. Surfers have to remain prepared and continuously observe the waves for their best guess of what wave they will get to ride.
https://phys.org/news/2021-07-surfing-science-weather-ocean.html?ut...
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Jul 26, 2021
Dr. Krishna Kumari Challa
Through the thin-film glass, researchers spot a new liquid phase
Research published in the Proceedings of the National Academy of Sciences describes a new type of liquid in thin films, which forms a high-density glass. Results generated in this study, conducted by researchers in Penn's Department of Chemistry, demonstrate how these glasses and other similar materials can be fabricated to be denser and more stable, providing a framework for developing new applications and devices through better design.
To make better glasses, researchers have used vapor deposition instead of cooling a liquid to produce a glass. In vapor deposition, a material is changed from a gas into a solid directly. While this method has allowed researchers to create denser types of bulk glasses, it was initially thought that thin glass films made using this method would still have the same liquid-like properties that would lead to degradation and instability.
After running all of the control experiments needed, the researchers were surprised to find that when using vapor deposition, they could access a different type of liquid, with a phase transition to the typical bulk liquid upon heating. A phase transition is when a material changes from from one state (gas, liquid, or solid) into another. "The two liquids have distinct structures, akin to graphene and diamond which are both solids made of carbon but exist in very different solid forms.
There are a lot of interesting properties that came out of nowhere, and nobody had thought that in thin films you would be able to see these phases. It's a new type of material.
Yi Jin el al., "Glasses denser than the supercooled liquid," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2100738118
https://phys.org/news/2021-07-thin-film-glass-liquid-phase.html?utm...
Jul 27, 2021
Dr. Krishna Kumari Challa
Plastic accumulation in food may be underestimated
A new study has found plastic accumulation in foods may be underestimated. There is also concern these microplastics will carry potentially harmful bacteria such as E. coli, which are commonly found in coastal waters, up the food chain.
Researchers tested a theory that microplastics covered in a biofilm coating (much like natural algae) were more likely to be ingested by oysters than microplastics that were completely clean. Although the experiment was carried out on oysters under laboratory conditions, scientists believe similar results could be found in other edible marine species that also filter seawater for food.
Up until now, studies to test the impacts of microplastics on marine life have typically used clean, virgin microplastics. However, this is not representative of what happens to microplastics in the marine environment. Bacteria readily colonize microplastics that enter the ocean. In this study, published in Science of the Total Environment, scientists compared the uptake rates of clean microplastics versus microplastics with an E.coli biofilm coating. The results were worrying—oysters contained 10 times more microplastics when exposed to the biofilm coated beads. It is hypothesized that these coated MPs appeared to be more like food to the oysters, explaining their preferential ingestion over clean microplastics.
The scientists say the implications for the food chain are concerning. The ingestion of microplastics is not only bad for the oysters, but it affects human health too. The plastic does not break down in the marine animal and is consumed when we eat it.
The findings in this research give us further insight into the potential harm microplastics are having on the food chain. It demonstrates how we could be vastly underestimating the effect that microplastics currently have. It is clear that further study is urgently needed.
Monica Fabra et al, The plastic Trojan horse: Biofilms increase microplastic uptake in marine filter feeders impacting microbial transfer and organism health, Science of The Total Environment (2021). DOI: 10.1016/j.scitotenv.2021.149217
https://phys.org/news/2021-07-plastic-accumulation-food-underestima...
Jul 27, 2021
Dr. Krishna Kumari Challa
COVID-19 immunity varies among genders and age groups
As experts continue to learn more about immune responses to COVID-19 and the effectiveness of vaccines, researchers.
indicates that the level of antibodies changes according to age groups, gender, symptoms, and time elapsed since vaccination. The findings are the latest from the researchers in a series of studies aimed at providing reliable measures on the effectiveness of COVID-19 vaccination. The new study examined the level of antibodies in over 26,000 blood samples taken from COVID-19 convalescents, as well as vaccinated and unvaccinated individuals. In vaccinated individuals, the researchers found differences between women and men in the concentration of antibodies in the blood relative to both age and gender.
In women, the level of antibodies begins to rise from the age of 51, and is higher than the levels found in men of similar age. This phenomenon may be related change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35, and may be related to changes in levels of testosterone and the effect on the immune system.
In young adults, a high concentration of antibodies generally signals a strong healthy functioning immune response, while in older demographics it typically indicates overreaction of the immune system associated with severe illness. In general, young adults were found to have a higher level of antibodies sustained for a longer period of time compared to older vaccinated persons. The findings further validate existing evidence that, depending on age, higher antibody count isn't necessarily equivalent to higher rates of recovery.
Furthermore, the study found that the immune response of vaccinated individuals (after two doses) is much stronger than that of people who have recovered from COVID-19. The findings show that vaccinated individuals have four times the level of antibodies compared to convalescents.
https://www.medrxiv.org/content/10.1101/2021.07.07.21259499v1
https://english.tau.ac.il/news/covid_immunity_varies
Jul 27, 2021
Dr. Krishna Kumari Challa
Innovative Gene Therapy ‘Reprograms’ Cells to Reverse Neurological Deficiencies
Jul 27, 2021
Dr. Krishna Kumari Challa
A Lagoon in Argentina Turned Bright Pink, But This Time The Reason Is Unnatural
The color is caused by sodium sulfite, an anti-bacterial product used in fish factories, whose waste is blamed for contaminating the Chubut river that feeds the Corfo lagoon and other water sources in the region, according to activists.
Residents have long complained of foul smells and other environmental issues around the river and lagoon.
Environmental engineer and virologist Federico Restrepo told AFP the coloration was due to sodium sulfite in fish waste, which by law, should be treated before being dumped.
https://www.sciencealert.com/prawn-chemical-turns-argentina-lake-br...
Jul 27, 2021
Dr. Krishna Kumari Challa
Acoustic Manipulation off a Reflective Surface
Jul 27, 2021
Dr. Krishna Kumari Challa
The Universe has an average colour – and it’s called cosmic latte
In a 2002 study, astronomers found that the light coming from galaxies (and the stars within them) – alongside all the visible clouds of gas and dust in the Universe – when averaged, would produce an ivory colour very close to white. They named this colour ‘cosmic latte’.
The ‘beigeness’ of the Universe is because there are slightly more regions that produce red, yellow and green light than those that produce blue. Averaged over the entire sky, however, this beige colour is diluted and appears almost, but not entirely, black.
https://www.sciencefocus.com/space/universe-average-colour-cosmic-l...
Jul 27, 2021
Dr. Krishna Kumari Challa
When our defences turn on us
When the body becomes the target of its own defensive arsenal, medicine must step in. This Nature Outlook explores why autoimmune disease is around three times more common in women than in men, the genetic variants that increase the risk of autoimmunity and how the microbes in our gut might sometimes be to blame. It also reveals how the possible links between long COVID and the immune system might finally prove that viruses can spark autoimmune disease.
Nature | Full collection
Jul 28, 2021
Dr. Krishna Kumari Challa
'Good cholesterol' may protect liver
The body's so-called good cholesterol may be even better than we realize. New research from Washington University School of Medicine in St. Louis suggests that one type of high-density lipoprotein (HDL) has a previously unknown role in protecting the liver from injury. This HDL protects the liver by blocking inflammatory signals produced by common gut bacteria. The study was published July 23 in the journal Science. HDL is mostly known for mopping up cholesterol in the body and delivering it to the liver for disposal. But in the new study, the researchers identified a special type of HDL called HDL3 that, when produced by the intestine, blocks gut bacterial signals that cause liver inflammation. If not blocked, these bacterial signals travel from the intestine to the liver, where they activate immune cells that trigger an inflammatory state, which leads to liver damage. Even though HDL has been considered good cholesterol,’ drugs that increase overall HDL levels have fallen out of favor in recent years because of clinical trials that showed no benefit in cardiovascular disease. study suggests that raising levels of this specific type of HDL, and specifically raising it in the intestine, may hold promise for protecting against liver disease, which, like heart disease, also is a major chronic health problem.
Any sort of intestinal damage can impact how a group of microbes called Gram-negative bacteria can affect the body. Such microbes produce an inflammatory molecule called lipopolysaccharide that can travel to the liver via the portal vein. The portal vein is the major vessel that supplies blood to the liver, and it carries most nutrients to the liver after food is absorbed in the intestine. Substances from gut microbes may travel along with nutrients from food to activate immune cells that trigger inflammation. In this way, elements of the gut microbiome may drive liver disease, including fatty liver disease and liver fibrosis, in which the liver develops scar tissue.
https://researchnews.cc/news/8017/-Good-cholesterol--may-protect-li...
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Jul 28, 2021
Dr. Krishna Kumari Challa
Fingertip-powered wearable
Jul 28, 2021
Dr. Krishna Kumari Challa
Physicists Have Figured Out How We Could Make Antimatter Out of Light
A new study by scientists has demonstrated how researchers may be able to create an accelerating jet of antimatter from light.
A team of physicists has shown that high-intensity lasers can be used to generate colliding gamma photons – the most energetic wavelengths of light – to produce electron-positron pairs. This, they say, could help us understand the environments around some of the Universe's most extreme objects: neutron stars.
The process of creating a matter-antimatter pair of particles – an electron and a positron – from photons is called the Breit-Wheeler process, and it's extremely difficult to achieve experimentally.
The probability of it taking place when two photons collide is very small. You need very high-energy photons, or gamma rays, and a lot of them, in order to maximize the chances of observation.
We don't yet have the capability to build a gamma-ray laser, so the photon-photon Breit-Wheeler process currently remains experimentally unachieved. But a team of physicists led by Yutong He of the University of California, San Diego (UC San Diego) has proposed a new workaround that, according to their simulations, could actually work.
It consists of a plastic block, carved with a pattern of criss-crossing channels on the micrometer scale. Two powerful lasers, one on either side of the block, fire strong pulses at this target.
"When the laser pulses penetrate the sample, each of them accelerates a cloud of extremely fast electrons.
These two electron clouds then race toward each other with full force, interacting with the laser propagating in the opposite direction."
The resulting collision is so energetic that it produces a cloud of gamma photons. These gamma photons should collide with each other to produce electron-positron pairs, in accordance with Einstein's theory of general relativity.
Even more excitingly, this process should generate powerful magnetic fields that collimate the positrons (rather than the electrons) into strongly accelerated, jet-shaped beams. In a distance of just 50 micrometers, the researchers found, the acceleration should increase the energy of the particles to one gigaelectronvolt.
Using a complex computer simulation, the researchers tested their model, and found that it should work, even when using less powerful lasers than previous proposals.
Not only would the collimation and acceleration of the positron beam improve the detection rate of the particles, but it bears a strong similarity to the powerful collimated particle jets beamed out by strongly magnetic, rapidly rotating neutron stars known as pulsars.
Scientists believe that processes that take place close to these stars could result in clouds of gamma radiation, similar to their proposed experiment.
https://www.nature.com/articles/s42005-021-00636-x
https://www.sciencealert.com/physicists-have-figured-out-how-we-cou...
Jul 28, 2021
Dr. Krishna Kumari Challa
The Hidden Beauty of Rainbows
Jul 29, 2021
Dr. Krishna Kumari Challa
Earth's 'vital signs' worsening as humanity's impact deepens
The global economy's business-as-usual approach to climate change has seen Earth's "vital signs" deteriorate to record levels, an influential group of scientists said recently, warning that several climate tipping points were now imminent.
The researchers, part of a group of more than 14,000 scientists who have signed on to an initiative declaring a worldwide climate emergency, said that governments had consistently failed to address the root cause of climate change: "the overexploitation of the Earth".
Of 31 "vital signs"—key metrics of planetary health that include greenhouse gas emissions, glacier thickness, sea-ice extent and deforestation—they found that 18 hit record highs or lows.
For example, despite a dip in pollution linked to the pandemic, levels of atmospheric CO2 and methane hit all-time highs in 2021.
Greenland and Antarctica both recently showed all-time low levels of ice mass, and glaciers are melting 31 percent faster than they did just 15 years ago, the authors said.
Both ocean heat and global sea levels set new records since 2019, and the annual loss rate of the Brazilian Amazon reached a 12-year high in 2020.
Echoing previous research, they said that forest degradation linked to fire, drought and logging was causing parts of the Brazilian Amazon to now act as a source of carbon, rather than absorb the gas from the atmosphere.
Livestock such as cows and sheep are now at record levels, numbering more than four billion and with a mass exceeding that of all humans and wild land mammals combined, they said.
We need to respond to the evidence that we are hitting climate tipping points with equally urgent action to decarbonise the global economy and start restoring instead of destroying nature, they stressed.
The researchers said there was "mounting evidence that we are nearing or have already crossed" a number of climate tipping points.
https://academic.oup.com/bioscience/advance-article/doi/10.1093/bio...
https://phys.org/news/2021-07-earth-vital-worsening-humanity-impact...
Jul 29, 2021