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Scientists Identify Extremely Tough Bacterial Species That Thrive Inside Concrete

Some types of bacteria are hardy enough to survive in the most inhospitable of conditions – and that includes concrete, as a new study proves. Not only can microbes survive in this dry, inhospitable building material, they can actually thrive there too.

Research shows that bacteria could provide early warnings of moisture-induced alkali-silica reactions (or 'concrete cancer') that can lead to structural deficiencies. Further down the line, we might even be able to harness bacteria to repair damage to bridges and roads.

While previous studies had already established that bacteria are able to make their homes inside concrete, here the scientists wanted to take a closer look at which microbes were present and how their communities might change over time.

After regular monitoring over two years on the roof of the lab, the most common bacteria discovered in the DNA analysis of the samples were Proteobacteria, Firmicutes, and Actinobacteria. Around 50-60 percent of the bacteria probably came from the raw materials, the researchers say, especially gravel.

The team observed that bacterial diversity dropped over time, though some types of bacteria had 'bounces' as the seasons changed – perhaps an indication that the availability of food sources was changing as well.

It's possible they're eating the dead bodies of other microbes. If there's nothing to eat, some of them can form spores or form a dormant cell type and do nothing until it rains, then eat as much as they can and go dormant again.

As some bacteria can produce calcium carbonate – which is suitable for filling in concrete cracks and pores – there's a hope that these microorganisms could be used to help repair buildings and infrastructure, though that sort of application is a long way off.

The researchers think  the microbes are not damaging the concrete.

https://journals.asm.org/doi/10.1128/mSystems.01153-20

https://www.sciencealert.com/some-bacteria-are-so-tough-they-can-gr...

Covid-19 patient develops rare white fungus abscess in brain after recovery

Lake Huron sinkhole surprise: The rise of oxygen on early Earth linked to changing planetary rotation rate

The rise of oxygen levels early in Earth's history paved the way for the spectacular diversity of animal life. But for decades, scientists have struggled to explain the factors that controlled this gradual and stepwise process, which unfolded over nearly 2 billion years.

Now an international research team is proposing that increasing day length on the early Earth—the spinning of the young planet gradually slowed over time, making the days longer—may have boosted the amount of oxygen released by photosynthetic cyanobacteria, thereby shaping the timing of Earth's oxygenation.

Their conclusion was inspired by a study of present-day microbial communities growing under extreme conditions at the bottom of a submerged Lake Huron sinkhole, 80 feet below the water's surface. The water in the Middle Island Sinkhole is rich in sulfur and low in oxygen, and the brightly colored bacteria that thrive there are considered good analogs for the single-celled organisms that formed mat-like colonies billions of years ago, carpeting both land and seafloor surfaces.

The researchers show that longer day length increases the amount of oxygen released by photosynthetic microbial mats. That finding, in turn, points to a previously unconsidered link between Earth's oxygenation history and its rotation rate. While the Earth now spins on its axis once every 24 hours, day length was possibly as brief as 6 hours during the planet's infancy.

Possible link between Earth's rotation rate and oxygenation, Nature Geoscience (2021). DOI: 10.1038/s41561-021-00784-3 , www.nature.com/articles/s41561-021-00784-3

https://phys.org/news/2021-08-lake-huron-sinkhole-oxygen-early.html...

 Scientists find the missing link in our body's blood pressure control

Researchers have determined the location of natural blood-pressure barometers inside our bodies that have eluded scientists for more than 60 years.

These cellular sensors detect subtle changes in blood pressure and adjust hormone levels to keep it in check. Scientists have long suspected that these barometers, or "baroreceptors," existed in specialized kidney cells called renin cells, but no one has been able to locate the baroreceptors until now.

The new findings finally reveal where the barometers are located, how they work and how they help prevent high blood pressure (hypertension) or low blood pressure (hypotension). The researchers hope the insights will lead to new treatments for high blood pressure.

the renin cells are sensors and responders.

Using a combination of innovative lab models, they determined that the baroreceptor was a "mechanotransducer" inside renin cells. This mechanotransducer detects pressure changes outside the cell, then transmits these mechanical signals to the cell nucleus, like how the cochlea in our ear turns sound vibrations into nerve impulses our brain can understand.

The researchers have unlocked exactly how the baroreceptors work. They found that applying pressure to renin cells in lab dishes triggered changes within the cells and decreased activity of the renin gene, Ren1. The scientists also compared differences in gene activity in kidneys exposed to lower pressure and those exposed to higher pressure.

Ultimately, when the baroreceptors detect too much pressure outside the renin cell, production of renin is restricted, while blood pressure that is too low prompts the production of more renin. This marvelous mechanism is vital to the body's ability to maintain the correct blood pressure. And now, after more than 60 years, we finally understand how and why.

Hirofumi Watanabe et al, Renin Cell Baroreceptor, a Nuclear Mechanotransducer Central for Homeostasis, Circulation Research (2021). DOI: 10.1161/CIRCRESAHA.120.318711

https://medicalxpress.com/news/2021-08-years-scientists-link-body-b...

Old vaccine for tuberculosis may help protect older people against COVID-19

A team of researchers from the CMR-National Institute for Research in Tuberculosis and the ICMR-National Institute of Epidemiology, both in India, has found evidence suggesting that an old vaccine used to reduce the threat of tuberculosis may give older people some protection against COVID-19. In their paper published in the journal Science Advances, the group describes their study of the Bacillus Calmette-Guérin (BCG) vaccine as a possible preventive measure for older people. Valerie Koeken with Radboud University Medical Center has published a Focus piece in the same journal issue explaining why inflammation is more of a concern with older people and outlining the work by the team in India.

As Koeken notes, as people grow older, they tend to develop low-grade, chronic inflammation, which makes them more susceptible to many types of diseases—it can also increase symptoms from diseases such as COVID-19, which explains in part why older people are much more likely to die from such infections. In this new effort, the researchers took a new look at an old vaccine to find out if it might prove useful for unvaccinated older people.

The study involved vaccinating 82 volunteers between the ages of 60 and 80 with the BCG vaccine and then studying blood samples taken a month later. In analyzing the samples, the researchers found decreases in several cytokines that have been associated with promoting inflammation: IL-6, type 1 interferons, interleukin-2 (IL-2) and TNF-alpha GM-CSF. The levels of the same cytokines were also found to be lower than those for a control group of unvaccinated volunteers. The researchers found that the BCG-vaccinated volunteers also had lower levels of some chemokines, such as matrix metalloproteinases and phase proteins, both of which have also been associated with promoting inflammation.

The researchers note that many of the cytokines that were reduced in the BCG volunteers have been identified as drivers of more severe COVID-19, which they also note suggests that the BCG vaccine might prove useful as a stop-gap measure for older people awaiting vaccination—if it could reduce inflammation in infected patients, it might save lives.

Nathella Pavan Kumar et al, Effect of BCG vaccination on proinflammatory responses in elderly individuals, Science Advances (2021). DOI: 10.1126/sciadv.abg7181

https://researchnews.cc/news/8238/Old-vaccine-for-tuberculosis-may-...

Researchers find possible culprit of inflammation that causes death...

As clinical evidence mounts that the leading cause of death in COVID-19 patients is the dangerous condition known as a cytokine storm, researchers have identified a protein in the blood that could be responsible. The team found that COVID-19 patients have significantly elevated levels of a protein called galectin-9 in their blood plasma. Perhaps more importantly, they also found a positive correlation between the levels of galectin-9 and pro-inflammatory cytokines released in the blood, which can lead to a cytokine storm. 

The findings suggest that galectin-9 levels in the body could be used as a biomarker to diagnose COVID-19 using a patient’s blood, potentially providing another non-invasive tool for COVID-19 testing. The levels could also be used to indicate the severity of the disease, though further study on that aspect is required.

The discovery of elevated galectin-9 levels in COVID-19 patients is important because of the positive correlation between the protein and a wide range of pro-inflammatory cytokines.

Cytokines as small cell-signalling proteins are involved in checks and balances in the immune system; they can turn on or turn off some cells to regulate the immune system. In the context of COVID, the problem is that there is a dysregulation of cytokine production—they are released very quickly in elevated levels. That’s what we call a ‘cytokine storm.

 galectin-9 is responsible for instructing immune cells to release the pro-inflammatory cytokines quickly in response to COVID-19 infection by binding to immune cells and forcing them to produce the cytokines. Further, as tissues are damaged as a result of inflammation, more galectin-9 is released from the cells—which activates more immune cells and releases more cytokines in a vicious cycle. The resulting cytokine storm damages tissue and organs, causes severe inflammation and can lead to death.

The next step is to develop treatments that block or inhibit the protein

https://journals.asm.org/doi/full/10.1128/mBio.00384-21

https://www.ualberta.ca/folio/2021/08/researchers-find-possible-cul...

Climate change: IPCC report is 'code red for humanity'

'It's not climate change, it's climate chaos', wars UN | UN Climate report 2021

Middle-age height loss linked to heightened death risk in northern European women

Height loss in middle age is linked to a heightened risk of early death, primarily from heart disease or stroke—at least in Northern European women—suggests research published in the online journal BMJ Open.

But regular physical activity may help to stave off mid-life shrinkage, as well as lowering cardiovascular disease risk, the findings indicate.

People tend to start losing height once they reach their 50s, a process that speeds up during their 70s. Height loss is usually caused by vertebral disc shrinkage, spinal compression fractures, and changes in posture.

While some degree of height loss is associated with natural aging, previous research suggests that it may also be associated with an increased risk of death from heart disease.

In the study, each cm of height loss was associated with 14% and 21% greater odds of death from any cause among the Swedish and Danish women, respectively, after adjusting for potentially influential factors.

Short stature and high leisure time physical activity (including participation in competitive sports) at study entry were associated with less height loss, independent of age.

Major height loss, defined as more than 2 cm, was associated with 74% and 80% greater odds of death, respectively, among two groups of women.

Other unmeasured factors may also have influenced the findings, they add. These include early life physical activity and exposure to tobacco (either through second-hand smoke or smoking themselves], peak bone mass, underlying health conditions and medical treatments.

Nevertheless, the findings prompt the researchers to conclude that mid-life height loss "is a risk marker for earlier mortality in northern European women."

Specifically, the risk of cardiovascular disease is increased in women who lose height, with death from stroke a major contributor to this association, they add.

 Loss of height predicts total and cardiovascular mortality: a cohort study of northern European women, BMJ Open (2021). DOI: 10.1136/bmjopen-2021-049122

https://medicalxpress.com/news/2021-08-middle-age-height-loss-linke...

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Organoid bladders reveal secrets of UTIs

Urinary tract infections (UTIs) are among the most common bacterial infections. They usually require treatment with antibiotics, and almost a quarter of treated cases lead to recurrent infection. The vast majority of UTIs are caused by a subspecies of the bacterium Escherichia coli, which infect cells that line the bladder wall and form what are known as “intracellular bacterial communities”.

The “communities” repeatedly rupture and bacteria re-enter neighboring cells, eventually killing off the so-called “umbrella cells” that line the outermost layer of the bladder’s epithelium. The loss of umbrella cells then allows the bacteria to invade the deeper layers of the bladder, where they can form “quiescent intracellular reservoirs” that are resistant to antibiotics and cause UTI recurrences. The dynamics of these events are hard to capture in vivo in animal models.

“Infection dynamics are difficult to capture from static imaging of tissue explants at serial time points,” says Kunal Sharma, the lead author on the two studies. “Thus far, in vitro models have not recapitulated bladder architecture with sufficient fidelity to study the time course of these events.”

Part 1

To address this, the group of Professor John McKinney at EPFL’s School of Life Sciences developed two complementary bladder models to study UTIs in a more controlled way. The first model consists of bladder organoids that recreate the 3D stratified architecture of the bladder epithelium. Organoids are tiny lab-grown tissues and organs that are anatomically correct and physiologically functional.

The second model is a bladder-on-a-chip that incorporates physiological stimuli, e.g. the mechanical effect of bladder filling and voiding, as well as an interface with the vasculature to study immune cell migration to sites of infection. The advances were published in the journals Cell Reports and eLife.

“By generating organoids from a mouse with a fluorescent label incorporated within cell membranes, we could use live-cell confocal imaging at EPFL’s BioImaging & Optics Core Facility to identify specific bacterial niches within the organoid with a high spatial resolution,” says Sharma. “By imaging multiple organoids, we managed to identify heterogeneity and diverse outcomes of host-pathogen interactions. This proof-of-concept system has shown promising potential for follow up studies on bacterial persistence to antibiotics and the dynamics of immune cell responses to infection.”

In combination with volumetric electron microscopy performed by EPFL’s Biological Electron Microscopy Facility, the researchers found that solitary bacteria rapidly invade into deeper layers of the bladder, independently of the formation of intracellular bacterial communities, where they are protected from antibiotics and host immune cells. These findings could be leveraged to improve UTI treatment strategies.

part 2

Innovative coating for blood vessels reduces rejection of transplanted organs
Researchers have found a way to reduce organ rejection following a transplant by using a special polymer to coat blood vessels on the organ to be transplanted.

The polymer, developed by UBC medicine professor Dr. Jayachandran Kizhakkedathu and his team at the Centre for Blood Research and Life Sciences Institute, substantially diminished rejection of transplants in mice when tested by collaborators at SFU and Northwestern University.
The findings were published in Nature Biomedical Engineering.

The discovery has the potential to eliminate the need for drugs—typically with serious side effects—on which transplant recipients rely to prevent their immune systems from attacking a new organ as a foreign object.

Blood vessels in our organs are protected with a coating of special types of sugars that suppress the immune system’s reaction, but in the process of procuring organs for transplantation, these sugars are damaged and no longer able to transmit their message.

Researchers now  synthesized a polymer to mimic these sugars and developed a chemical process for applying it to the blood vessels. This new technology  prevented rejection in the studies.

The procedure has been applied only to blood vessels and kidneys in mice so far. Clinical trials in humans could still be several years away. Still, the researchers are optimistic it could work equally well on lungs, hearts and other organs, which would be great news for prospective recipients of donated organs.

1. Erika M. J. Siren, Haiming D. Luo, Franklin Tam, Ashani Montgomery, Winnie Enns, Haisle Moon, Lyann Sim, Kevin Rey, Qiunong Guan, Jiao-Jing Wang, Christine M. Wardell, Mahdis Monajemi, Majid Mojibian, Megan K. Levings, Zheng J. Zhang, Caigan Du, Stephen G. Withers, Jonathan C. Choy, Jayachandran N. Kizhakkedathu. Prevention of vascular-allograft rejection by protecting the endothelial glycocalyx with immunosuppressive polymers. Nature Biomedical Engineering, 2021; DOI: 10.1038/s41551-021-00777-y

https://researchnews.cc/news/8271/Innovative-coating-for-blood-vess...

Chameleon robot: 

Hyeonseok Kim et al, Biomimetic chameleon soft robot with artificial crypsis and disruptive coloration skin, Nature Communications (2021). DOI: 10.1038/s41467-021-24916-w

https://techxplore.com/news/2021-08-soft-robot-chameleon-real-time-...

Lichens may one day detoxify the air in your home

When smoke from fires darken the skies as they did last summer, hunkering down indoors makes good sense. But on most days throughout the year, the air we breathe indoors carries far more pollutants than outdoor air. Exposure is highest in crowded homes where space is a luxury, leading the EPA to rank indoor air quality as one of the top five public health concerns.

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Skull birth defect detailed in cell-by-cell description

Contrary to the popular song, the neck bone is actually connected to one of 22 separate head bones that make up the human skull. These plate-like bones intersect at specialized joints called sutures, which normally allow the skull to expand as the brain grows, but are absent in children with a birth defect called craniosynostosis. A new study in Nature Communications presents a detailed cellular atlas of the developing coronal suture, the one most commonly fused as a consequence of single gene mutations. 

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Humans will always have oxygen to breathe, but we can't say the sam...

There is nothing more fundamental to humans than the availability of oxygen. We give little thought to the oxygen we need, we just breathe, but where does it come from?

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Study says 'blue hydrogen' likely bad for climate

Use of "clean" hydrogen has been seen as a viable and environmentally benign energy alternative, but a study released Thursday said it could lead to higher greenhouse gas emissions than coal.

Touted as clean, 'blue' hydrogen may be worse than gas, coal

"Blue" hydrogen—an energy source that involves a process for making hydrogen by using methane in natural gas—is being lauded as a clean, green energy to help reduce global warming. But Cornell and Stanford University researchers believe it may harm the climate more than burning fossil fuel.

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Is your mobile provider tracking your location? This new technology...

Right now, there is a good chance your phone is tracking your location—even with GPS services turned off. That's because, to receive service, our phones reveal personal identifiers to cell towers owned by major network operators. This has led to vast and largely unregulated data-harvesting industries based around selling users' location data to third parties without consent.

A glucose-COVID-19 hypothesis

In normal conditions, the lungs have the necessary immune defense to contain SARS-CoV-2 and avoid spread of the infection. If elevated, glucose impairs this primary defense system making ideal conditions for the SARS-CoV-2 to invade the pulmonary cells and spread into the rest of the body.

The 'Second Brain' in Your Gut Might Have Evolved Before The Brain in Your Head
The enteric nervous system (ENS) in our gut operates a lot like other neural networks in the brain and the spinal cord – so much so that it's often called the 'second brain'. Now a new study has revealed more about how exactly the ENS works.
Using a recently developed technique combining high-resolution video recordings with an analysis of biological electrical activity, scientists were able to study the colons of mice, and in particular the way that the gut moves its contents along.

One of the key findings was discovering how the thousands of neurons inside the ENS communicate with each other, causing contractions in the gastrointestinal tract to aid the digestive process. Up until now, it wasn't clear how these neurons were able to join forces to do this.

"Interestingly, the same neural circuit was activated during both propulsive and non-propulsive contractions.

The team found large bunches of connecting neurons firing to propel the contents of the colon further down the gut, via both excitatory (causing action) and inhibitory (blocking action) motor neurons.

The discovery means the ENS is made up of a more advanced network of circuitry, covering a wider section of the gut and involving a greater amount of different types of neurons working in tandem than had previously been thought.

Another important finding is that this activity is significantly different from the propulsion that's seen in other muscle organs around the body that don't have a built-in nervous system, such as lymphatic vessels, ureters, or the portal vein.

"The mechanism identified is more complex than expected and vastly different from fluid propulsion along other hollow smooth muscle organs," the researchers explain in their paper.

The team says it backs up the hypothesis that the ENS is in fact the 'first brain' rather than the second one – suggesting that it may have evolved in animals a long time before our actual brains took their current form.

https://www.nature.com/articles/s42003-021-02485-4

https://www.sciencealert.com/we-have-a-brain-like-system-in-our-gut...

Physicists Detect Strongest Evidence Yet of Matter Generated by Collisions of Light

According to theory, if you smash two photons together hard enough, you can generate matter: an electron-positron pair, the conversion of light to mass as per Einstein's theory of special relativity.

It's called the Breit-Wheeler process, first laid out by Gregory Breit and John A. Wheeler in 1934, and we have very good reason to believe it would work.

But direct observation of the pure phenomenon involving just two photons has remained elusive, mainly because the photons need to be extremely energetic (i.e. gamma rays) and we don't have the technology yet to build a gamma-ray laser.

Now, physicists at Brookhaven National Laboratory say they've found a way around this stumbling block using the facility's Relativistic Heavy Ion Collider (RHIC) - resulting in a direct observation of the Breit-Wheeler process in action.

But what do accelerated ions have to do with photon collisions? Well, we can explain.

The process involves, as the collider's name suggests, accelerating ions - atomic nuclei stripped of their electrons. Because electrons have a negative charge and protons (within the nucleus) have a positive one, stripping it leaves the nucleus with a positive charge. The heavier the element, the more protons it has, and the stronger the positive charge of the resulting ion.

The team used gold ions, which contain 79 protons, and a powerful charge. When gold ions are accelerated to very high speeds, they generate a circular magnetic field that can be as powerful as the perpendicular electric field in the collider. Where they intersect, these equal fields can produce electromagnetic particles, or photons.

"So, when the ions are moving close to the speed of light, there are a bunch of photons surrounding the gold nucleus, traveling with it like a cloud.

part 1

At the RHIC, ions are accelerated to relativistic speeds - those that are a significant percentage of the speed of light. In this experiment, the gold ions were accelerated to 99.995 percent of light speed.

This is where the magic happens: When two ions just miss each other, their two clouds of photons can interact, and collide. The collisions themselves can't be detected, but the electron-positron pairs that result can.

However, it's not enough to just detect an electron-positron pair, either.

That's because the photons produced by the electromagnetic interaction are virtual photons, popping briefly in and out of existence, and without the same mass as their 'real' counterparts.

To be a true Breit-Wheeler process, two real photons need to collide - not two virtual photons, nor a virtual and a real photon.

part 2

At the ions' relativistic speeds, the virtual particles can behave like real photons. Thankfully, there's a way physicists can tell which electron-positron pairs are generated by the Breit-Wheeler process: the angles between the electron and the positron in the pair generated by the collision.

Each type of collision - virtual-virtual, virtual-real and real-real - can be identified based on the angle between the two particles produced. So the researchers detected and analyzed the angles of over 6,000 electron-positron pairs generated during their experiment.

They found that the angles were consistent with collisions between real photons - the Breit-Wheeler process in action.

"We also measured all the energy, mass distributions, and quantum numbers of the systems. They are consistent with theory calculations for what would happen with real photons.

"Our results provide clear evidence of direct, one-step creation of matter-antimatter pairs from collisions of light as originally predicted by Breit and Wheeler."

The argument could be very reasonably made that we won't have a direct first detection of the pure, single photon-photon Breit-Wheeler process until we collide photons approaching the energy of gamma rays.

Nevertheless, the team's work is highly compelling stuff - at the very least, it shows that we are barking up the right tree with Breit and Wheeler.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.052302

Part 3

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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...