Can you Stand On Liquid Mercury?

Dendrimers: The tiny tentacles shown to evade our immune response

Tiny synthetic particles known as dendrimers avoid detection by our immune system and could help develop a new way to deliver drugs into the body without triggering a reaction.

The dendrimer is a chemically-created molecule with tentacles branching out in a highly-symmetrical structure around a central core. The research describes how dendrimer tentacles arranged incredibly closely to each other—less than one nanometer apart—avoided detection by the complement system, part of our immune system.

Our immune system is equipped with many tools to recognize and eliminate invaders. For example, our blood contains sensors belonging to a family of defense system known as the "complement system," which recognizes unique patterns expressed by invaders such as bacteria and viruses. Binding of these sensors to pathogens alarms the immune system and triggers an immune response. These sensors are termed "complement pattern-recognition (CPR)" molecules.

CPR can sense surface patterns that are regularly repeated so close to each other, for instance in 2–15 nanometer ranges—a distance, which is at least 5000 times thinner than the thickness of a typical sheet of paper.

The international team discovered however, that the CPR could not sense patterns repeated closer to each other, for instance, at 1 nanometer or less.

At a nanoscale level, the team grew tiny particles known as dendrimers which are shaped like trees with many branches—or tiny tentacles. The number of tentacles exponentially increases with dendrimer size and the tentacles are positioned less than 1 nanometer from each other. The ends of tentacles are where regular patterns appear. Depending on chemical structure of these patterns, they found that these dendrimers could escape detection by the CPR radar.

Dendrimers offer us the ability to deliver drugs to diseased sites where inflammation is a major problem such as in conditions like atherosclerosis, cancer, macular degeneration  and rheumatoid arthritis.

Lin-Ping Wu et al, Dendrimer end-terminal motif-dependent evasion of human complement and complement activation through IgM hitchhiking, Nature Communications (2021). DOI: 10.1038/s41467-021-24960-6

https://phys.org/news/2021-08-dendrimers-tiny-tentacles-shown-evade...

Combining classical and quantum systems to meet supercomputing demands

Quantum entanglement is one of the most fundamental and intriguing phenomena in nature. Recent research on entanglement has proven to be a valuable resource for quantum communication and information processing. Now, scientists from Japan have discovered a stable quantum entangled state of two protons on a silicon surface, opening doors to an organic union of classical and quantum computing platforms and potentially strengthening the future of quantum technology.

One of the most interesting phenomena in quantum mechanics is "quantum entanglement." This phenomenon describes how certain particles are inextricably linked, such that their states can only be described with reference to each other. This particle interaction also forms the basis of quantum computing. And this is why, in recent years, physicists have looked for techniques to generate entanglement. However, these techniques confront a number of engineering hurdles, including limitations in creating large number of "qubits" (quantum bits, the basic unit of quantum information), the need to maintain extremely low temperatures (<1 K), and the use of ultrapure materials. Surfaces or interfaces are crucial in the formation of quantum entanglement. Unfortunately, electrons confined to surfaces are prone to "decoherence," a condition in which there is no defined phase relationship between the two distinct states. Thus, to obtain stable, coherent qubits, the spin states of surface atoms (or equivalently, protons) must be determined.

Recently, a team of scientists  recognized the need for stable qubits. By looking at the surface spin states, the scientists discovered an entangled pair of protons on the surface of a silicon nanocrystal.

Proton entanglement has been previously observed in molecular hydrogen and plays an important role in a variety of scientific disciplines. However, the entangled state was found in gas or liquid phases only. Now, researchers have detected quantum entanglement on a solid surface, which can lay the groundwork for future quantum technologies.

The scientists studied the spin states using a technique known as "inelastic neutron scattering spectroscopy" to determine the nature of surface vibrations. By modeling these surface atoms as "harmonic oscillators," they showed anti-symmetry of protons. Since the protons were identical (or indistinguishable), the oscillator model restricted their possible spin states, resulting in strong entanglement. Compared to the proton entanglement in molecular hydrogen, the entanglement harbored a massive energy difference between its states, ensuring its longevity and stability. Additionally, the scientists theoretically demonstrated a cascade transition of terahertz entangled photon pairs using the proton entanglement.

Takahiro Matsumoto et al, Quantum proton entanglement on a nanocrystalline silicon surface, Physical Review B (2021). DOI: 10.1103/PhysRevB.103.245401

https://phys.org/news/2021-08-worlds-combining-classical-quantum-su...

Newtonian physics for babies

Antibodies Stop Sperm in Their Tracks

Engineered antibodies trap and immobilize human sperm in the reproductive tract of female sheep, paving the way for possible use as a nonhormonal contraceptive in people.

Currently, most available birth control options are barrier methods or rely on hormones to prevent fertilization of an egg—both of which have drawbacks, such as discomfort or side effects, that make them less than ideal for some people. Enter antisperm antibodies, described in a study published today (August 11) in Science Translational Medicine. Researchers generated antibodies that recognize an antigen unique to human sperm. When delivered topically to the reproductive tracts of sheep, the antibodies successfully bound and trapped more than 99.9 percent of introduced human sperm. Some of the authors have spun out a company, Mucommune, in order to continue the development of contraceptives based on these antibodies.

Previous work showed that some women’s bodies naturally produce antibodies to sperm that can lead to a type of immunological infertility. Lai’s group used the antigen binding fragment from one of these antibodies, which recognizes a sperm-specific antigen known as CD52g, in a study published in 2020, where they engineered an IgG antibody with four of the antigen-binding fragments and showed that it and the original, naturally-occurring IgG antibody with two antigen binding domains trapped sperm in vitro. 

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In the new study, Lai and colleagues added multiple antigen-binding fragments—6, 8, or 10—to an IgG antibody and then introduced expression plasmids into human embryonic kidney cells so the cells would produce them and researchers could isolate them. The team tested the antibodies’ ability to immobilize sperm in vitro, where the antibodies with extra antigen-binding fragments trapped sperm at least 10 times more effectively than the original IgG antibody with just two antigen-binding fragments. 

To explore the effects of the antibodies in vivo, the researchers introduced the original IgG antibody, one with 6 or 10 antigen-binding fragments, or saline into the vaginas of female sheep, which are similar to the human female reproductive tract, and then simulated intercourse and delivered a human semen sample. Two minutes later, they retrieved the sample and analyzed sperm movement. At a high dose (333 micrograms of antibody), all three antibodies tamped down nearly all sperm motility, and at a low dose (33.3 micrograms), both modified antibodies, but not the original IgG, trapped more than 90 percent of sperm.

https://stm.sciencemag.org/content/13/606/eabd5219

https://www.the-scientist.com/news-opinion/antibodies-stop-sperm-in...

Scientists show how blocking opioid receptors in specific neurons can restore breathing during an overdose

Opioid overdose deaths are caused by disrupted breathing, but the actual mechanism by which these drugs suppress respiration was not understood. Now, a new study by  scientists has identified a group of neurons in the brainstem that plays a key role in this process.

The new findings show how triggering specific receptors in these neurons causes opioid-induced respiratory depression, or OIRD, the disrupted breathing that causes overdose deaths. It also shows how blocking these receptors can cause OIRD to be reversed.

Opioids work by binding to proteins on nerve cells (neurons) called opioid receptors and subsequently inhibiting their activity. Currently, naloxone is the only medication known to block the effects of opioids and reverse an overdose. But naloxone has limitations, including a short duration that requires it to be administered multiple times. It also works systemically, blocking opioid receptors throughout the entire body, including those that control pain.

In the new study, the researchers identified a group of neurons that express a certain type of opioid receptor (the mu opoid receptor) and are located in the brainstem breathing modulation center; they then characterized these neurons' role in OIRD.

They found that mice that were genetically engineered to lack opioid receptors in these neurons didn't have their breathing disrupted when exposed to morphine, as mice in the control group did. The researchers also found that, without introducing opioids, stimulating these receptors in control mice caused symptoms of OIRD.

The team then looked at ways to reverse the process by treating the overdosed mice with chemical compounds targeted to other receptors on the same neurons, which play an opposite role as the opioid receptor (activating rather than inhibiting them).

Shijia Liu et al, Neural basis of opioid-induced respiratory depression and its rescue, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2022134118

https://medicalxpress.com/news/2021-08-scientists-blocking-opioid-r...

Our Metabolism Changes With Age, But It's Not When You Think

Metabolism – the rate that we burn calories to keep our bodies running – changes as we age.

A new study looking at metabolism across the generations has come up with some rather surprising findings.

The researchers were able to pull in a huge amount of data from 6,421 people across 29 countries and with an age range of 8 days old to 95 years old. By using isotopes placed in drinking water and then tracked through urine, researchers worked out a daily energy expenditure figure for each participant.

Contrary to popular belief, pound-for-pound our metabolic rate peaks when we're infants. So, when we're teenagers, we're only burning calories at a slighter faster rate than when we're middle-aged.

The thickening waistlines associated with middle age might not all be down to a slow metabolic rate, in other words.

As young people, our metabolisms seem to slow down by about 3 percent until our 20s, when they level off, the data showed – there's no real spurt over puberty. During our 20s through to our 50s, that's when our metabolic rate seems to be the most stable.

Once we hit our 60s, researchers found that our metabolisms seem to slow down by about 0.7 percent a year. By the time a person reaches their 90s, on average they need 26 percent fewer calories for energy per day than someone who's middle-aged – not just because of less muscle mass, but because their cells are slowing down.

But it's during the first 12 months of life that energy needs really shift. A 1-year-old burns calories around 50 percent faster for their body size than an adult. Even controlling for rapid increases in weight, energy use is "rocketing" in these early months, according to researchers.

The findings could be useful is in tailoring health treatments to specific people and specific age ranges, taking shifts in metabolism into account.

https://science.sciencemag.org/content/373/6556/808

Can "squirrelly" skills be built into robots?

Deforestation Can Cause Rapid Evolutionary Changes in Insects

People in New Zealand have cut down so many trees, some native insects are losing their wings.

In the space of 750 years, humans have changed the natural landscape of the country's South Island so much, scientists say it's causing rapid evolutionary changes among certain species.

With no more alpine forest to break the strong mountaintop winds, at least one type of insect is already transitioning out of the flight industry.

Zelandoperla fenestrata is a stonefly with two distinct phenotypes: one with wings, capable of flight; and one with stunted wings or even none, described as flightless.

The flightless type of stonefly is usually found at higher altitudes, where trees are scarce and strong winds can therefore easily blow a flying insect out into the abyss. Meanwhile, the flight-capable flies are typically sheltered in alpine forests, where insects need to explore the full extent of the habitat.

However, in regions where alpine forests have been cut down, researchers have noticed something intriguing. The insects at this elevation, which should usually be able to fly, can't do so.

It appears that human-caused deforestation has indirectly deprived these insects of their ability to fly, and we did so in a very short span of time.

In addition to the local shifts inferred here, it is likely that widespread deforestation has increased the proportion of flightless lineages across large areas of southern New Zealand.

The researchers worry  that without wings, stoneflies won't be able to search for mates in a larger territorial range, thus increasing genetic diversity. This could possibly impact the species' health in the long run, as well as the insects' risk of extinction.

https://royalsocietypublishing.org/doi/10.1098/rsbl.2021.0069

Pollinators: First global risk index for species declines and effects on humanity

Disappearing habitats and use of pesticides are driving the loss of pollinator species around the world, posing a threat to "ecosystem services" that provide food and wellbeing to many millions—particularly in the Global South—as well as billions of dollars in crop productivity.

This is according to an international panel of experts, led by the University of Cambridge, who used available evidence to create the first planetary risk index of the causes and effects of dramatic pollinator declines in six global regions.

The bees, butterflies, wasps, beetles, bats, flies and hummingbirds that distribute pollen, vital for the reproduction of over 75% of  food crops and flowering plants—including coffee, rapeseed and most fruits—are visibly diminishing the world over, yet little is known of the consequences for human populations.

What happens to pollinators could have huge knock-on effects for humanity. These small creatures play central roles in the world's ecosystems, including many that humans and other animals rely on for nutrition. If they go, we may be in serious trouble.

The top three global causes of pollinator loss are habitat destruction, followed by land management—primarily the grazing, fertilizers and crop monoculture of farming—and then widespread pesticide use, according to the study. The effect of climate change comes in at number four, although data are limited.

Perhaps the biggest direct risk to humans across all regions is "crop pollination deficit": falls in quantity and quality of food and biofuel crops. Experts ranked the risk of crop yield "instability" as serious or high across two-thirds of the planet—from Africa to Latin America—where many rely directly on pollinated crops through small-holder farming.

Increasingly unusual climatic phenomena, such as extreme rainfall and temperature, are already affecting crops. Pollinator loss adds further instability.

A global-scale expert assessment of drivers and risks associated with pollinator decline, Nature Ecology & Evolution (2021). DOI: 10.1038/s41559-021-01534-9 , www.nature.com/articles/s41559-021-01534-9

https://phys.org/news/2021-08-pollinators-global-index-species-decl...

Fighting fungal infections with smart nanotech

Newly engineered nanoparticles the size of coronavirus  developed by scientists are punching well above their weight when it comes to treating drug-resistant fungal infections.

They have  a remarkable ability to battle one of the most invasive and notoriously resistant fungal infections—Candida albicans. Micelles are made of lipid molecules that arrange themselves in a spherical form in aqueous solutions. They both attract and repel liquids, making them particularly well suited for drug delivery.

Candida albicans is an opportunistic pathogenic yeast that is extremely dangerous to people with compromised immune systems, particularly those in a hospital setting. Found on many surfaces, Candida albicans is notorious for its resilience to anti-fungal medicines. It is the most prevalent cause of fungal infections worldwide and can cause serious infections that can affect the blood, heart, brain, eyes, bones, and other parts of the body.

The new polymer-based micelles could revolutionize current anti-fungal medicines.

Fungal biofilms are surface-loving microbials that thrive on implanted devices such as catheters, prostheses and heart valves, making the presence of these devices a major risk factor for infection.

"In places like India—which has nearly 40,000 new COVID-19 infections every day—hospital resources are severely stretched, leaving healthcare workers are not only battling COVID-19, but also dealing with complacency and fatigue.

"The unfortunate result is that infection control practices have deteriorated, putting patients on mechanical ventilation at greater risk of developing bacterial or fungal infections.

"As fungal biofilms tend to seed recurrent infections, finding ways to break and beat the infection cycle is critical, especially now. 

smart micelles that have the ability to break down single and multi-species biofilms to significantly inhibit the growth of Candida albicans, one of the most virulent fungal species.

Researchers estimate that the new micelles could improve the efficacy of anti-fungal medicines by 100-fold, potentially saving the lives of millions of people worldwide. 

These micelles have a unique ability to solubilize and entrap a range of important antifungal drugs to significantly improve their performance and efficacy."

This is the first time that polymer-based micelles have been created with intrinsic capabilities to prevent fungal biofilm formation.

The new micelles will remove up to 70 percent of infection, this could be a real game changer for treating fungal diseases.

 Yassamin N. Albayaty et al, Polymeric micelles with anti-virulence activity against Candida albicans in a single- and dual-species biofilm, Drug Delivery and Translational Research (2021). DOI: 10.1007/s13346-021-00943-4

Yassamin N. Albayaty et al, pH-Responsive copolymer micelles to enhance itraconazole efficacy against Candida albicans biofilms, Journal of Materials Chemistry B (2020). DOI: 10.1039/C9TB02586C

https://phys.org/news/2021-08-fungal-infections-giant-smart-nanotec...

How jet streams affect our weather: an in-depth guide

Wildfire smoke can reduce raindrops to meaningless drizzle, study says. Here's how

When wildfires burn, they catapult smoke into the atmosphere. These plumes are loaded with tiny particles that act as magnets for water droplets sitting in clouds—the more smoky particles ejected into the sky, the more rain comes down.

So, researchers assumed that more wildfires equal more rainfall. But a new study flipped those assumptions upside down. Turns out, the murky relationship between wildfire smoke and cloud formation only holds true for clouds high in the atmosphere.

For those closer to the ground, the mingling of smoky particles may actually make it less likely that rain will fall, triggering a cascade of reactions that fuel instead of calm fire activity on land.

They found that clouds hovering above wildfires contained about five times the number of droplets than clouds free of smoky particles, yet the droplets were half the size of those in their "clean" counterparts.

This unexpected size difference, researchers say, is what could determine if we will experience a downpour or a meaningless drizzle.

Cynthia H. Twohy et al, Biomass Burning Smoke and Its Influence on Clouds Over the Western U. S., Geophysical Research Letters (2021). DOI: 10.1029/2021GL094224

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Smaller droplets are less likely to grow into heavier ones that will eventually fall as rain, meaning wildfire seasons could be exacerbated by drier conditions on land that ultimately fuel more and larger blazes.

https://phys.org/news/2021-08-wildfire-raindrops-meaningless-drizzl...

Plastic debris in soil aids growth of dangerous fungi

Scientists have discovered a potentially lethal link between fungi that cause diseases and small pieces of plastic debris of less than five millimetres in soil.

The fungi identified cause medical problems such as swelling in the lungs and allergy symptoms including coughing and wheezing, according to the study published in Scientific Reports last month.

One of the lung diseases, known as chronic obstructive pulmonary disease, led to 3.23 million deaths in 2019 globally, with more than 80 per cent of the deaths occurring in low- and middle-income countries, according to the World Health Organization.

The researchers established the link between disease-causing fungi and small plastics by analysing soil samples from sites near human settlements in the town of Siaya, in western Kenya, including a marketplace, a dump site, a roadside and a courtyard.

These microplastics [small pieces of plastic debris] create a conducive environment for fungal growth, by trapping soil water and other nutrients on their surfaces, enabling the fungi to attach themselves and grow and multiply, according to researchers.

https://www.nature.com/articles/s41598-021-92405-7

https://www.scidev.net/global/multimedia/plastic-debris-in-soil-aid...

Why are bubbles round?

Bubbles occur when a thin film (for example, of soapy water) traps some gas (for example, air). The molecules in the film are attracted to each other, which not only holds the film together, but also makes it shrink to the smallest possible area.

The smallest area enclosing any given volume? A sphere. Therefore, the film will shrink to cover a sphere, and then can’t shrink any further because of the trapped air. Thus, bubbles end up as round.

https://www.sciencefocus.com/science/why-are-bubbles-round/?utm_sou...

Protein may protect against neurodegenerative diseases

Cells translate their genetic material at rapid rates with exquisite precision to reproduce, repair damage or even combat disease. But the process can deregulate and give rise to disease. Byproducts of errant processes can build up like gunk in the gears, especially around neurons, breaking down the repair mechanisms and causing further damage and even neurodegenerative disorders such as Alzheimer's disease.

Now, an international research team may have found that a protein implicated in tumour growth may be able to help regulate awry cellular translation and protect against neuronal decay. They published their results on July 13 in the Cell Reports.

"Researchers have begun to understand that age-related neurodegenerative diseases may be caused by slow but steady accumulation of toxic peptide products, which leads to death of neurons, such as beta-amyloid plaques causing Alzheimer's disease.

Repeat-associated non-AUG (RAN) translation is one of the mechanisms that generates such toxic products."

When replicating their genetic material, cells look for specifically ordered markers that signal the spot where they should start and end the copy to make a specific protein. The signal is typically "AUG," but RAN translation doesn't need this signal and can begin processing at other points. The problem is that RAN translation can end up copying bits of repeated genetic information that become the toxic buildup that leads to neurodegeneration.

In diseased conditions, 5MP is a protein that can potentially transform a healthy cell into a tumor cell. In healthy conditions, 5MP mimics a protein involved in regulating RAN translation. The researchers used electron microscopy and computer-directed modeling to reveal the structure of the preinitiation complex of molecules that assemble prior to RAN translation beginning. They found that 5MP competes with the protein it mimics in human cells and, when it wins, it reduces RAN translation and its toxic byproducts.

part 1

To better understand how this finding translates to disease outcomes, the researchers engineered flies with fragile X-associated tremor ataxia syndrome, a neurodegenerative disorder. They found that increasing the levels of 5MP in the affected flies repressed neuronal toxicity and enhanced their lifespan.

"Taken together, these data suggest that modulation of 5MP levels could be a viable therapeutic target by which to selectively reduce RAN translation in repeat expansion disorders

Chingakham Ranjit Singh et al, Human oncoprotein 5MP suppresses general and repeat-associated non-AUG translation via eIF3 by a common mechanism, Cell Reports (2021). DOI: 10.1016/j.celrep.2021.109376

part 2

https://medicalxpress.com/news/2021-08-protein-neurodegenerative-di...

Histamine could be a key player in depression, according to study in mice

Bodily inflammation dampens levels of a "feel-good molecule" and antidepressants' ability to boost them, according to new research in mice.

The findings, from researchers at Imperial College London and University of South Carolina, add to mounting evidence that inflammation, and the accompanying release of the molecule histamine, affects a key molecule responsible for mood in the brain—serotonin.

If replicated in humans, the findings—which identify histamine as a "new molecule of interest" in depression—could open new avenues for treating depression, which is the most common mental health problem worldwide.

Inflammation—a blanket term describing an immune response—triggers the release of histamine in the body. This increases blood flow to affected areas to flood them with immune cells. While these effects help the body fight infections, both long-term and acute inflammation is increasingly linked to depression.

Inflammation accompanies infections but can also be caused by stress, allergic responses and a host of chronic diseases such as diabetes, obesity, cancer and neurodegenerative diseases.

Melinda Hersey et al, Inflammation-Induced Histamine Impairs the Capacity of Escitalopram to Increase Hippocampal Extracellular Serotonin, The Journal of Neuroscience (2021). DOI: 10.1523/JNEUROSCI.2618-20.2021

https://medicalxpress.com/news/2021-08-histamine-key-player-depress...

Quantum entanglement is explained in classic terms

In many quantum measurement experiments and thought experiments, measurement results appear that do not seem to have classic explanations. As example: In quantum particle spin experiments, entangled particles appear to interact instantly across distances; and in interferometer experiments, one measurement result appears to be split over two paths. Currently, these measurement phenomena are treated as unique to quantum mechanics and not understandable in classic physics. Recognizing calibration in theory explains and resolves all the differences that appear to occur between classic and quantum measurements.

https://sciencex.com/news/2021-08-quantum-entanglement-classic-term...

More information: M. Born (editor), The Born-Einstein Letters, page 158, Macmillan, London, 1971. "Spooky action at a distance" is a phrase Einstein applied.

J. C. Maxwell, A Treatise on Electricity and Magnetism, 3rd Edition (1891), Dover Publications, New York, 1954, page 1.

L. Euler, Elements of Algebra, Chapter I, Article I, #3. Third edition, Longman, Hurst, Rees, Orme and Co., London England, 1822. Page 1: "Now, we cannot measure or determine one quantity, except by considering some other quantity of the same kind as known, and pointing out their mutual relation." www.google.com/books/edition/E … &printsec=frontcover

International Vocabulary of Metrology (VIM) 3rd edition, BIPM JCGM 200:2012, para. 2.39 calibration. www.bipm.org/en/publications/guides/vim.html

Measurement, Vol 182, September 2021 doi.org/10.1016/j.measurement.2021.109625

Wash your hands for 20 seconds: Physics shows why

Though hand-washing is proven effective in combating the spread of disease and infection, the physics behind it has rarely been studied. But in Physics of Fluids, researchers describe a simple model that captures the key mechanics of hand-washing.

By simulating hand-washing, they estimated the time scales on which particles, like viruses and bacteria, were removed from hands.

The mathematical model acts in two dimensions, with one wavy surface moving past another wavy surface, and a thin film of liquid between the two. Wavy surfaces represent hands because they are rough on small spatial scales.

Particles are trapped on the rough surfaces of the hand in potential wells. In other words, they are at the bottom of a valley, and in order for them to escape, the energy from the water flow must be high enough to get them up and out of the valley.

The strength of the flowing liquid depends on the speed of the moving hands. A stronger flow removes particles more easily.

Basically, the flow tells you about the forces on the particles. Then you can work out how the particles move and figure out if they get removed.

If you move your hands too gently, too slowly, relative to one another, the forces created by the flowing fluid are not big enough to overcome the force holding the particle down.

It takes about 20 seconds of vigorous movement to dislodge potential viruses and bacteria.

"Will we ever wash our hands of lubrication theory?" Physics of Fluids (2021). aip.scitation.org/doi/10.1063/5.0060307

https://phys.org/news/2021-08-seconds-physics.html?utm_source=nwlet...

Physics shows why 20 seconds is right for hand-washing

Majority of climate change news coverage now accurate: study

Two decades ago, print media frequently gave equal credence to both legitimate climate experts and outlier climate deniers. But researchers found in more recent years that the media around the globe actually got it right most of the time. However, facts now outweigh a debate.

Nine out of ten media stories accurately reported the science on human contributions to climate change. It's not portrayed as a two-sided debate anymore.

Lucy McAllister et al, Balance as bias, resolute on the retreat? Updates & analyses of newspaper coverage in the United States, United Kingdom, New Zealand, Australia and Canada over the past 15 years, Environmental Research Letters (2021). DOI: 10.1088/1748-9326/ac14eb

https://phys.org/news/2021-08-majority-climate-news-coverage-accura...

Three in four say climate 'tipping points' close

Some 73 percent of people now believe that Earth's climate is approaching abrupt and irreversible "tipping points" due to human activity, according to a global opinion poll released on17th August, 2021.

Scientists are increasingly concerned that some feedback loops in nature—such as irreversible melting of icesheets or permafrost—may be close to being triggered as mankind's mind-boggling carbon emissions show no signs of slowing, despite a pandemic.

The IPCC report warned that Earth is on course to be 1.5C hotter than pre-industrial times around 2030—a full decade earlier than it projected just three years ago.

Tuesday's survey, conducted by the Global Commons Alliance and Ipsos MORI, found four out of five respondents wanted to do more to protect the planet.

The world is not sleepwalking towards catastrophe. People know we are taking colossal risks, they want to do more and they want their governments to do more, polls say.

Tuesday's survey showed that people in developing nations were more likely to be willing to protect nature and the climate than those in richer countries.

Ninety-five percent of respondents in Indonesia, and 94 percent in South Africa, said they would do more for the planet, compared with just 70 percent and 74 percent in Germany and the United States, respectively.

https://www.ipsos.com/ipsos-mori/en-uk/global-commons-survey-attitu...

The secret of the Stradivari violin confirmed

New research  has confirmed that renowned violin maker Antonio Stradivari and others treated their instruments with chemicals that produced their unique sound, and several of these chemicals have been identified for the first time.

Joseph Nagyvary, professor emeritus of biochemistry at Texas A&M, who first proposed the theory that chemicals used in making the violins—not so much the skill of making the instrument itself—was the reason Stradivari and others, such as Guarneri del Gesu, made instruments whose sound has not been equaled in over 200 years. An international team led by Hwan-Ching Tai, professor of chemistry at National Taiwan University, has had their findings published in Angewandte Chemie International Edition.

About 40 years ago at Texas A&M, Nagyvary was the first to prove a theory that he had spent years researching: that a primary reason for the pristine sound, beyond the fine craftsmanship, was the chemicals Stradivari and others used to treat their instruments due to a worm infestation at the time.

Their  research over many years has been based on the assumption that the wood of the great masters underwent an aggressive chemical treatment, and this had a direct role in creating the great sound of the Stradivari and the Guarneri.

These findings were verified in a review by the American Chemical Society, the world's largest scientific organization.

The current findings of the research team show that borax, zinc, copper and alum—along with lime water—were used to treat the wood used in the instruments.

The presence of these chemicals all points to collaboration between the violin makers and the local drugstore and druggist at the time. Both Stradivari and Guarneri would have wanted to treat their violins to prevent worms from eating away the wood because worm infestations were very widespread at that time."

He said that each violin maker probably used his own home-grown methods when treating the wood.

"This new study reveals that Stradivari and Guarneri had their own individual proprietary method of wood processing, to which they could have attributed a considerable significance," he said. "They could have come to realize that the special salts they used for impregnation of the wood also imparted to it some beneficial mechanical strength and acoustical advantages. These methods were kept secret. There were no patents in those times. How the wood was manipulated with chemicals was impossible to guess by the visual inspection of the finished product.

He said that the varnish recipes were not secret because the varnish itself is not a critical determinant of tone quality. In contrast, the process of how the fresh spruce planks were treated and processed with a variety of water-based chemical treatments is critical for the sound of the finished violin.

Such knowledge was needed to gain a "competitive advantage" over other instrument makers.

 Cheng‐Kuan Su et al, Materials Engineering of Violin Soundboards by Stradivari and Guarneri, Angewandte Chemie International Edition (2021). DOI: 10.1002/anie.202105252

https://phys.org/news/2021-08-secret-stradivari-violin.html?utm_sou...

Cities are making mammals bigger

A new study shows urbanization is causing many mammal species to grow bigger, possibly because of readily available food in places packed with people.

The finding runs counter to many scientists' hypothesis that cities would trigger mammals to get smaller over time. Buildings and roads trap and re-emit a greater degree of heat than green landscapes, causing cities to have higher temperatures than their surroundings, a phenomenon known as the urban heat island effect.. Animals in warmer climates tend to be smaller than the same species in colder environments, a classic biological principle called Bergmann's Rule.

But  researchers discovered an unexpected pattern when they analyzed nearly 140,500 measurements of body length and mass from more than 100 North American mammal species collected over 80 years: City-dwelling mammals are both longer and heftier than their rural counterparts.

In theory, animals in cities should be getting smaller because of these heat island effects, but the researchers didn't find evidence for this happening in mammals. This paper is a good argument for why we can't assume Bergmann's Rule or climate alone is important in determining the size of animals.

Maggie M. Hantak et al, Mammalian body size is determined by interactions between climate, urbanization, and ecological traits, Communications Biology (2021). DOI: 10.1038/s42003-021-02505-3

https://phys.org/news/2021-08-cities-mammals-bigger.html?utm_source...

 Preserve a Strawberry Forever?

First steerable catheter developed for brain surgery

A team of engineers and physicians has developed a steerable catheter that for the first time will give neurosurgeons the ability to steer the device in any direction they want while navigating the brain's arteries and blood vessels. The device was inspired by nature, specifically insect legs and flagella—tail-like structures that allow microscopic organisms such as bacteria to swim.

The steerable catheter was successfully tested in pigs .

Tilvawala Gopesh et al, Soft robotic steerable microcatheter for the endovascular treatment of cerebral disorders, Science Robotics (2021). DOI: 10.1126/scirobotics.abf0601https://techxplore.com/news/2021-08...

Rattlesnake rattles trick human ears

Rattlesnakes increase their rattling rate as potential threats approach, and this abrupt switch to a high-frequency mode makes listeners, including humans, think they're closer than they actually are, researchers report August 19th in the journal Current Biology.

The acoustic display of rattlesnakes, which has been interpreted for decades as a simple acoustic warning signal about the presence of the snake, is in fact a far more intricate interspecies communication signal. The sudden switch to the high-frequency mode acts as a smart signal fooling the listener  about its actual distance to the sound source. The misinterpretation of distance by the listener thereby creates a distance safety margin.

Additional results showed that rattlesnakes adapt their rattling rate in response to the approach velocity of an object rather than its size.

Snakes do not just rattle to advertise their presence, but they evolved an innovative solution: a sonic distance warning device similar to the one included in cars while driving backwards.

Current Biology, Forsthofer and Schutte et al.: "Frequency modulation of rattlesnake acoustic display affects acoustic distance perception in humans" www.cell.com/current-biology/f … 0960-9822(21)00973-8 , DOI: 10.1016/j.cub.2021.07.018

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Rattlesnakes vigorously shake their tails to warn other animals of their presence. Past studies have shown that rattling varies in frequency, but little is known about the behavioral relevance of this phenomenon or what message it sends to listeners. Researchers noticed that rattling increased in frequency when they approached rattlesnakes but decreased when they walked away.

https://phys.org/news/2021-08-rattlesnake-rattles-human-ears.html?u...

Scientists harness human protein to deliver molecular medicines to cells

Researchers have developed a new way to deliver molecular therapies to cells. The system, called SEND, can be programmed to encapsulate and deliver different RNA cargoes. SEND harnesses natural proteins in the body that form virus-like particles and bind RNA, and it may provoke less of an immune response than other delivery approaches.

Segel M, Lash B, et al. Mammalian retrovirus-like protein PEG10 packages its own mRNA and can be pseudotyped for intercellular mRNA delivery. Science. Online August 19, 2021. DOI: 10.1126/science.abg6155

https://medicalxpress.com/news/2021-08-scientists-harness-human-pro...

This exotic particle had an out-of-body experience; these scientists took a picture of it

Scientists have taken the clearest picture yet of electronic particles that make up a mysterious magnetic state called quantum spin liquid (QSL).

The achievement could facilitate the development of superfast quantum computers and energy-efficient superconductors.

The scientists are the first to capture an image of how electrons in a QSL decompose into spin-like particles called spinons and charge-like particles called chargons.

 Ruan, W., Chen, Y., Tang, S. et al. Evidence for quantum spin liquid behaviour in single-layer 1T-TaSe2 from scanning tunnelling microscopy. Nat. Phys. (2021). doi.org/10.1038/s41567-021-01321-0 , www.nature.com/articles/s41567-021-01321-0

https://phys.org/news/2021-08-exotic-particle-out-of-body-scientist...

Researchers discover hidden SARS-CoV-2 'gate' that opens to allow COVID infection

Since the early days of the COVID pandemic, scientists have aggressively pursued the secrets of the mechanisms that allow severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to enter and infect healthy human cells.

Researchers  have discovered how glycans—molecules that make up a sugary residue around the edges of the spike protein—act as infection gateways. They essentially figured out how the spike actually opens and infects. The research team's gate discovery opens potential avenues for new therapeutics to counter SARS-CoV-2 infection. If glycan gates could be pharmacologically locked in the closed position, then the virus is effectively prevented from opening to entry and infection.

A glycan gate controls opening of the SARS-CoV-2 spike protein, Nature Chemistry (2021). DOI: 10.1038/s41557-021-00758-3 , www.nature.com/articles/s41557-021-00758-3

https://phys.org/news/2021-08-hidden-sars-cov-gate-covid-infection....

We throw away a third of the food we grow – here’s what to do about waste

One-third of all food produced each year is squandered or spoiled before it can be consumed. Research also suggests that high-income countries waste as much food as sub-Saharan Africa produces.

This food waste then ends up in landfills to rot – which releases greenhouse gases. And when this is combined with the amount of energy it takes to produce, manufacture, transport and store this food, it contributes a staggering 3 billion tonnes of carbon dioxide to our planet. To put that in context, if food waste was a country, it would be the third-highest emitter of greenhouse gases in the world, after the US and China.

But the good news is there are numerous techniques, technologies and policies that together could help reduce global food waste at every point in the process of producing and consuming it.

According to the Food and Agriculture Organisation for the United Nations, lack of infrastructure, limited knowledge on storage and food handling, combined with unfavourable climatic conditions, can lead to a lot of food spoilage and waste in low-income countries.

On the other hand, in high-income countries, aesthetic preferences and arbitrary sell-by dates mean food easily becomes waste. Cosmetic blemishes, produce that is too ripe, too big, too little or even the wrong shape can lead to perfectly good fruits and vegetables going to waste.

As the global population continues to increase, it places real pressure on world food production. So we must stop food wastage. what are the causes for food waste?

 1.plant diseases and pests – along with poor harvesting techniques – can be a big factor in the high levels of food waste 

artificial intelligence (AI) powered drones can help farmers become more resourceful and reduce the overuse of pesticides in food production. This is important because pesticides can adversely affect the food ecosystem. 

part1 

A big part of the food waste problem is changing how we shop and view food and our mindset around what constitutes waste. But research shows the best way to tackle food waste among consumers is to highlight the potential money that can be saved as well as the “feel-good factor”, or moral value, of doing a good thing for the environment. knowledge on how to use leftovers to create new meals helps a lot.

A more creative approach to food waste comes via a circular food system, which prevents food waste from being discarded. It can, for example, be converted into renewable energy. Waste can even be transformed into more food for humans (for example, tofu from leftover soybeans), as well as animal feed.

Support businesses or restaurants that use waste foods in their products or meals. Planning your meals around sell-by dates. Not throwing out food if it’s a bit wilted or bruised and only buying what you need – especially on special occasions where food can often go uneaten and to waste.

You can also show supermarkets that “wonky” fruit and veggies are just as good as the “normal” shaped produce by buying these over the perfect looking pears or potatoes.

Ultimately, it’s not going to be any single thing that solves food waste, but a collective approach can enable us to make the changes that need to happen.

https://theconversation.com/we-throw-away-a-third-of-the-food-we-gr...

part2

Experimental confirmation of wave-particle duality

The 21st century has undoubtedly been the era of quantum science. Quantum mechanics was born in the early 20th century and has been used to develop unprecedented technologies which include quantum information, quantum communication, quantum metrology, quantum imaging, and quantum sensing. However, in quantum science, there are still unresolved and even inapprehensible issues like wave-particle duality and complementarity, superposition of wave functions, wave function collapse after quantum measurement, wave function entanglement of the composite wave function, etc.

To test the fundamental principle of wave-particle duality and complementarity quantitatively, a quantum composite system that can be controlled by experimental parameters is needed. So far, there have been several theoretical proposals after Neils Bohr introduced the concept of "complementarity" in 1928, but only a few ideas have been tested experimentally, with them detecting interference patterns with low visibility. Thus, the concept of complementarity and wave-particle duality still remains elusive and has not been fully confirmed experimentally yet.

To address this issue, a research team from the Institute for Basic Science (IBS, South Korea) constructed a double-path interferometer consisting of two parametric downconversion crystals seeded by coherent idler fields. The device generates coherent signal photons (quantons) that are used for quantum interference measurement. The quantons then travel down two separate paths before reaching the detector. The conjugate idler fields are used for extracting path information with controllable fidelity, which is useful for quantitatively elucidating the complementarity.

Quantitative Complementarity of Wave-Particle Duality, Science Advances (2021). DOI: 10.1126/sciadv.abi9268

https://phys.org/news/2021-08-experimental-wave-particle-duality.ht...

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Alternative cement with low carbon footprint developed

Researchers at the Martin Luther University Halle-Wittenberg (MLU) in Germany and the Brazilian University of Pará have developed a climate-friendly alternative to conventional cement. Carbon dioxide (CO2) emissions can be reduced during production by up to two thirds when a previously unused overburden from bauxite mining is used as a raw material. The alternative was found to be just as stable as the traditional Portland cement. The results were published in Sustainable Materials and Technologies.

Why sports concussions are worse for women

The damage that causes concussion can be quite subtle. The brain can’t move that much in the skull, explains Stewart. “The brain virtually fills the intercranial cavity, and there’s a little thin film of fluid that fills up what space is left.” But, in the split second after an impact, the head rapidly decelerates, and the resulting forces transmit deep inside the brain. The gelatinous grey matter undergoes significant shear forces when the head stops suddenly, pushing and pulling the brain tissue in a way that can cause structural damage.

And those forces can affect the brains of men and women in profoundly different ways.

https://www.nature.com/articles/d41586-021-02089-2?utm_source=Natur...

Part 2

Long COVID Might Be The Manifestation of a Different Virus Reawakened in The Body

People who struggle to recover from COVID-19 could be battling more than just SARS-CoV-2. Their immune systems might also be involved with another virus as well.

Ever since patients first started reporting long hauls of COVID-19, many of their lingering symptoms, such as fatigue and brain fog, have been compared to chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME).

New research suggests that's no coincidence. In some cases, both chronic illnesses might have similar roots. A recent study among 185 COVID-19 patients in the United States has found the majority of 'long haulers' the researchers tested were positive for Epstein-Barr virus (EBV) reactivation.

Recent research has found that a subset of CFS/ME patients show signs of EBV reactivation, and now, it seems that a potentially large percentage of people with long COVID do as well.

EBV is one of the most common viral infections out there. The vast majority of people around the world contract the virus at some point in their lives, and after the acute infection phase, an inactive version of the virus sticks around in the body for a lifetime.

Sometimes, EBV can reactivate and cause flu-like symptoms, such as during periods of psychological or physiological stress.

Like a global pandemic.

https://www.mdpi.com/2076-0817/10/6/763

https://www.sciencealert.com/mounting-evidence-suggests-many-covid-...

Scientists then and now

How Science Affects Your Ice Cream

There's science inside your ice cream, and it tastes delicious

Swimming robot gives fresh insight into locomotion and neuroscience

Hubble Captures a Stunning 'Einstein Ring'

Gravity is the weird, mysterious glue that binds the Universe together, but that's not the limit of its charms. We can also leverage the way it warps space-time to see distant objects that would be otherwise much more difficult to make out.

This is called gravitational lensing, an effect predicted by Einstein, and it's beautifully illustrated in a new release from the Hubble Space Telescope.

In the center in the image (below) is a shiny, near-perfect ring with what appear to be four bright spots threaded along it, looping around two more points with a golden glow.

This is called an Einstein ring, and those bright dots are not six galaxies, but three: the two in the middle of the ring, and one quasar behind it, its light distorted and magnified as it passes through the gravitational field of the two foreground galaxies.

Because the mass of the two foreground galaxies is so high, this causes a gravitational curvature of space-time around the pair. Any light that then travels through this space-time follows this curvature and enters our telescopes smeared and distorted – but also magnified.

This, as it turns out, is a really useful tool for probing both the far and near reaches of the Universe. Anything with enough mass can act as a gravitational lens. That can mean one or two galaxies, as we see here, or even huge galaxy clusters, which produce a wonderful mess of smears of light from the many objects behind them.

Astronomers peering into deep space can reconstruct these smears and replicated images to see in much finer detail the distant galaxies thus lensed. But that's not all gravitational lensing can do. The strength of a lens depends on the curvature of the gravitational field, which is directly related to the mass it's curving around.

So gravitational lenses can allow us to weigh galaxies and galaxy clusters, which in turn can then help us find and map dark matter – the mysterious, invisible source of mass that generates additional gravity that can't be explained by the stuff in the Universe we can actually detect.

https://esahubble.org/images/potw2132a/

People with rare autoimmune diseases are at higher risk of death from Covid-19

New research has revealed that people with rare autoimmune rheumatic diseases are at an increased risk of developing Covid-19 and subsequently dying from it. Experts found that people with these conditions were 54% more likely to test positive for a Covid-19 infection, and death related to Covid-19 was 2.4 times more likely than for people in the general population when age and sex was taken into account. Researchers say there is an urgent need to understand the effectiveness of the vaccine among people with diseases such as vasculitis and lupus. The findings, published as a pre-print in medRxiv and currently under peer review, is the work of a team of doctors and researchers from RECORDER (Registration of Complex Rare Diseases Exemplars in Rheumatology), which is a joint project between the University of Nottingham, Nottingham University Hospitals NHS Trust and the National Disease Registration Service at Public Health England.

In this latest study, funded by the British Society for Rheumatology and Vasculitis UK, the team looked at nearly 170,000 people in England with rare autoimmune rheumatic diseases. Between March and July 2020, during the first wave of the Covid-19 pandemic in England, they found:

• 1,874 people (1.11%) had Covid-19 infection (PCR test positive)

• Taking age into account, the infection rate in people with rare autoimmune rheumatic diseases was 54% higher than in the general population

• 713 (0.42%) people living with rare autoimmune rheumatic disease died related to Covid-19 infection

• Covid-19 related death was 2.4 times more common in people with rare autoimmune rheumatic disease compared to the general population (taking age and sex into account)

These findings are particularly important as recently published data show that people who are immunosuppressed, which includes many people with rare autoimmune rheumatic diseases, can have lower levels of protection from Covid-19 vaccination due to a weaker immune response.

https://www.nottingham.ac.uk/news/rare-autoimmune-diseases-and-covi...

'Missing jigsaw piece’: engineers make critical advance in quantum computer design

Food allergy and intolerance: the differences

Gut bacteria and flavonoid-rich foods are linked and improve blood pressure levels

Flavonoid-rich foods, including berries, apples, pears and wine, appear to have a positive effect on blood pressure levels, an association that is partially explained by characteristics of the gut microbiome, according to new research published today in Hypertension, an American Heart Association journal.

Our gut microbiome plays a key role in metabolizing flavonoids to enhance their cardioprotective effects, and this study provides evidence to suggest these blood pressure-lowering effects are achievable with simple changes to the daily diet.

Flavonoids are compounds found naturally in fruits, vegetables and plant-based foods such as tea, chocolate and wine, and have been shown in previous research to offer a variety of health benefits to the body. Flavonoids are broken down by the body's gut microbiome—the bacteria found in the digestive tract. Recent studies found a link between gut microbiota, the microorganisms in the human digestive tract, and cardiovascular disease (CVD), which is the leading cause of death worldwide. Gut microbiota is highly variable between individuals, and there are reported differences in gut microbial compositions among people with and without CVD.

With increased research suggesting flavonoids may reduce heart disease risk, this study assessed the role of the gut microbiome on the process. Researchers examined the association between eating flavonoid-rich foods with blood pressure and gut microbiome diversity. The study also investigated how much variance within the gut microbiome could explain the association between intake of flavonoid-rich foods and blood pressure.

Microbial Diversity and Abundance of Parabacteroides Mediate the Associations Between Higher Intake of Flavonoid-Rich Foods and Lower Blood Pressure, Hypertension (2021). www.ahajournals.org/doi/10.116 … TENSIONAHA.121.17441

part 1

The analysis of regular flavonoid intake with gut microbiome and blood pressure levels found:

• Study participants who had the highest intake of flavonoid-rich foods, including berries, red wine, apples and pears, had lower systolic blood pressure levels, as well as greater diversity in their gut microbiome than the participants who consumed the lowest levels of flavonoid-rich foods.
• Up to 15.2% of the association between flavonoid-rich foods and systolic blood pressure could be explained by the diversity found in participants' gut microbiome.
• Eating 1.6 servings of berries per day (one serving equals 80 grams, or 1 cup) was associated with an average reduction in systolic blood pressure levels of 4.1 mm Hg, and about 12% of the association was explained by gut microbiome factors.

• Drinking 2.8 glasses (125 ml of wine per glass) of red wine a week was associated with an average of 3.7 mm Hg lower systolic blood pressure level, of which 15% could be explained by the gut microbiome.

https://medicalxpress.com/news/2021-08-gut-bacteria-flavonoid-rich-...

part 2

High-efficiency ultraviolet light emitting diodes to sterilize pathogens, including SARS -CoV-2

Every year, thousands of lives and billions of dollars are spent worldwide as a result of health-care associated and waterborne illnesses. Sterilization is a critical preventative measure and it can be achieved by a number of techniques including irradiation using ultraviolet (UV) light. This need has gained greater urgency because of the global coronavirus pandemic, as effective sterilization practices can curtail the spread of infectious diseases.

Current sources like mercury lamps are bulky, contain toxic chemicals and are not as versatile in applications as semiconductor light sources. AlGaN is the material of choice for high efficiency deep UV light sources, which is the only alternative technology to replace mercury lamps for water purification and disinfection. To date, however, AlGaN-based mid and deep UV LEDs exhibit very low efficiency. One of the primary limiting factors is the poor hole injection, due to the ineffective p-type doping of AlGaN alloys using Mg, especially for the high Al composition alloys that are essential for the UV-C (200-280 nm) wavelength ranges.

A promising technique that can overcome this challenge and enhance hole injection into the device active region is by utilizing a tunnel junction structure. The hole injection in such devices is driven by the interband transport of electrons from the valence band of the p-type layer to the conduction band of the n-type layer.