Fire tornadoes explained

The roaring Bootleg Fire burning up swaths of southwestern Oregon is the nation's largest wildfire so far this year and intense enough that it's triggering weather phenomena, including lightning, massive columns of smoke and ash clouds reaching high into the atmosphere, and even the possibility of a "fire tornado." Loretta Mickley, senior research fellow in chemistry-climate interactions at the Harvard John A. Paulson School of Engineering and Applied Sciences, has examined the interaction of wildfires and climate and published research on the likelihood that the wildfires will grow larger and more frequent in the years to come. The Gazette spoke to Mickley to better understand the causes, dangers, and expectations for the future.

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Planetary shields will buckle under stellar winds from their dying ...

Any life identified on planets orbiting white dwarf stars almost certainly evolved after the star's death, says a new study led by the University of Warwick that reveals the consequences of the intense and furious stellar winds that will batter a planet as its star is dying. The research is published in Monthly Notices of the Royal Astronomical Society, and lead author Dr. Dimitri Veras will present it today (21 July) at the online National Astronomy Meeting (NAM 2021).

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Windows 10/11 vulnerability exposes admin passwords to local users

A Twitter user has found and made public a Windows 10/11 vulnerability that exposes admin passwords to local users who can then escalate their privileges up to admin, giving them total system access. As he notes on his posts, he found that Windows Security Account Manager (SAM) data could be read by users with very limited privileges, giving them access to admin passwords. Microsoft apparently caught wind of the vulnerability and posted an Executive Summary of the issue on its Security Vulnerability page.

Phage-based COVID vaccines

RNA breakthrough creates crops that can grow 50% more potatoes, rice

Manipulating RNA can allow plants to yield dramatically more crops, as well as increasing drought tolerance, announced a group of scientists.

In initial tests, adding a gene encoding for a protein called FTO to both rice and potato plants increased their yield by 50% in field tests. The plants grew significantly larger, produced longer root systems and were better able to tolerate drought stress. Analysis also showed that the plants had increased their rate of photosynthesis.

The change really is dramatic. What's more, it worked with almost every type of plant scientists tried it with so far, and it's a very simple modification to make.

We know that the RNA molecule reads DNA, then makes proteins to carry out tasks. But RNA doesn't simply read the DNA blueprint and carry it out blindly; the cell itself can also regulate which parts of the blueprint get expressed. It does so by placing chemical markers onto RNA to modulate which proteins are made and how many. Scientists realized that this had major implications for biology. 

They focused on a protein called FTO, the first known protein that erases chemical marks on RNA. The scientists knew it worked on RNA to affect cell growth in humans and other animals, so they tried inserting the gene for it into rice plants—and then watched in amazement as the plants took off.

The rice plants grew three times more rice under laboratory conditions. When they tried it out in real field tests, the plants grew 50% more mass and yielded 50% more rice. They grew longer roots, photosynthesized more efficiently, and could better withstand stress from drought.

The scientists repeated the experiments with potato plants, which are part of a completely different family. The results were the same.

That suggested a degree of universality that was extremely exciting.

RNA demethylation increases the yield and biomass of rice and potato plants in field trials, Nature Biotechnology, DOI: 10.1038/s41587-021-00982-9 , www.nature.com/articles/s41587-021-00982-9

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It took the scientists longer to begin to understand how this was happening. Further experiments showed that FTO started working early in the plant's development, boosting the total amount of biomass it produced.

The scientists think that FTO controls a process known as m6A, which is a key modification of RNA. In this scenario, FTO works by erasing m6A RNA to muffle some of the signals that tell plants to slow down and reduce growth. 

https://phys.org/news/2021-07-rna-breakthrough-crops-potatoes-rice....

How newborn mammals dream the world they're entering

As a newborn mammal opens its eyes for the first time, it can already make visual sense of the world around it. But how does this happen before they have experienced sight?

A new  study suggests that, in a sense, mammals dream about the world they are about to experience before they are even born.

Scientists describe the process as waves of activity that emanate from the neonatal retina in mice before their eyes ever open.

This activity disappears soon after birth and is replaced by a more mature network of neural transmissions of visual stimuli to the brain, where information is further encoded and stored.

But how do the circuits form that allow us to perceive motion and navigate the world? It turns out we are born capable of many of these behaviors, at least in rudimentary form.

Scientists explored the origins of these waves of activity. Imaging the brains of mice soon after birth but before their eyes opened, the Yale team found that these retinal waves flow in a pattern that mimics the activity that would occur if the animal were moving forward through the environment.

This early dream-like activity makes evolutionary sense because it allows a mouse to anticipate what it will experience after opening its eyes, and be prepared to respond immediately to environmental threats.

They also investigated the cells and circuits responsible for propagating the retinal waves that mimic forward motion in neonatal mice. They found that blocking the function of starburst amacrine cells, which are cells in the retina that release neurotransmitters, prevents the waves from flowing in the direction that mimics forward motion. This in turn impairs the development of the mouse's ability to respond to visual motion after birth.

Intriguingly, within the adult retina of the mouse these same cells play a crucial role in a more sophisticated motion detection circuit that allows them to respond to environmental cues.

Mice, of course, differ from humans in their ability to quickly navigate their environment soon after birth. However, human babies are also able to immediately detect objects and identify motion, such as a finger moving across their field of vision, suggesting that their visual system was also primed before birth.

These brain circuits are self-organized at birth and some of the early teaching is already done. It's like dreaming about what you are going to see before you even open your eyes.

X. Ge el al., "Retinal waves prime visual motion detection by simulating future optic flow," Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abd0830

https://phys.org/news/2021-07-eyes-wide-newborn-mammals-world.html?...

Why delta variant is highly transmissible 

In a preprint posted 12 July¹, the researchers report that virus was first detectable in people with the Delta variant four days after exposure,compared with an average of six days among people with the original strain, suggesting that Delta replicates much faster. Individuals infected with Delta also had viral loads up to 1,260 times higher than those in people infected with the original strain.

The combination of a high number of viruses and a short incubation period makes sense as an explanation for Delta’s heightened transmissibility.

The sheer amount of virus in the respiratory tract means that superspreading events are likely to infect even more people, and that people might begin spreading the virus earlier after they become infected.

And the short incubation makes contact tracing more difficult in some countries.

Putting it all together, Delta’s really difficult to stop.

The highly contagious Delta variant of Covid-19 is expected to become the dominant strain of the virus over the coming months, according to the World Health Organization.

https://www.medrxiv.org/content/10.1101/2021.07.07.21260122v1

https://www.nature.com/articles/d41586-021-01986-w?utm_source=Natur...

The science of underwater swimming: How staying submerged gives Olympians the winning edge

To win swimming gold in Tokyo, swimmers not only have to generate incredible power with their arms and legs to propel themselves through the water; they also have to overcome the relentless pull of the water's drag while doing so.

Without being able to don special low-drag suits or use technologies to help them fly over the water, how can swimmers make the effect of the water's drag as small as possible?

The best athletes in this year's Olympics will do it by swimming under, rather than on top of, the water—at least as far as the rules allow.

Water is much denser than air, so you might assume swimmers would benefit from using a technique that allows them to sit high in the water, with as much of their body out of the water as possible.

But there are two problems with this strategy.

First, it costs energy to produce the forces needed to lift the body, which would be better spent propelling the swimmer forwards towards the finishing wall.

Second, when we travel on the water's surface we waste energy making waves. During fast swimming, such as in the sprint freestyle events or during starts and turns (where speeds exceed 2 meters per second, or about 7 kilometers per hour), wave generation slows the swimmer down more than any other factor. Reducing wave formation is therefore vital to swimming success.

Waves are produced as the pressure exerted by the swimmer on the water forces the water upwards and out of their path. Other pressure changes around the swimmer's body also cause waves to form behind them, and sometimes to the side.

The energy required to generate waves comes from the swimmer themselves, so a lot of the power generated by the swimmer's muscles is used in wave generation rather than moving the swimmer forwards.

But waves aren't formed when we (or fish, dolphins or whales) swim under the water, because waves only form when an object (like us) moves at the boundary between two fluids of different densities, such as water and air during swimming. And this fact hints at an intriguing solution to the drag issue.

Here, the swimmer propels themselves underwater by undulating the lower body in a wave-like manner while maintaining a rigid and streamlined upper body position with arms stretched overhead.

The amplitude of the lower body undulation increases from the hips to the feet so the "wave" produced by the body is much greater down towards the feet, creating a whip-like effect. This pushes water rapidly backwards, propelling the swimmer forwards according to Newton's law of action and reaction.

Although some aspects of underwater swimming is banned, the benefits of improving the underwater undulation technique are so great that swimmers still spend hours each week in training improving this part of the race.

https://theconversation.com/the-science-of-underwater-swimming-how-...

Cockatoos   have learned to open curb-side bins — and it has global significance

In a study published in Molecular Psychiatry,  a research team show that changes in the extracellular matrix of the brain scaffolding around nerve cells  lead to loss of memory with ageing, but that it is possible to reverse these using genetic treatments. Recent evidence has emerged of the role of perineuronal nets (PNNs) in neuroplasticity  the ability of the brain to learn and adapt  and to make memories. PNNs are cartilage-like structures that mostly surround inhibitory neurons in the brain. Their main function is to control the level of plasticity in the brain. They appear at around five years old in humans, and turn off the period of enhanced plasticity during which the connections in the brain are optimised. Then, plasticity is partially turned off, making the brain more efficient but less plastic. PNNs contain compounds known as chondroitin sulphates. Some of these, such as chondroitin 4-sulphate, inhibit the action of the networks, inhibiting neuroplasticity; others, such as chondroitin 6-sulphate, promote neuroplasticity. As we age, the balance of these compounds changes, and as levels of chondroitin 6-sulphate decrease, so our ability to learn and form new memories changes, leading to age-related memory decline.

They investigated whether manipulating the chondroitin sulphate composition of the PNNs might restore neuroplasticity and alleviate age-related memory deficits.

To do this, the team looked at 20-month old mice – considered very old – and using a suite of tests showed that the mice exhibited deficits in their memory compared to six-month old mice.

For example, one test involved seeing whether mice recognised an object. The mouse was placed at the start of a Y-shaped maze and left to explore two identical objects at the end of the two arms. After a short while, the mouse was once again placed in the maze, but this time one arm contained a new object, while the other contained a copy of the repeated object. The researchers measured the amount of time the mouse spent exploring each object to see whether it had remembered the object from the previous task. The older mice were much less likely to remember the object.

The team treated the ageing mice using a ‘viral vector’, a virus capable of reconstituting the amount of 6-sulphate chondroitin sulphates to the PNNs and found that this completely restored memory in the older mice, to a level similar to that seen in the younger mice.

1. Sujeong Yang, Sylvain Gigout, Angelo Molinaro, Yuko Naito-Matsui, Sam Hilton, Simona Foscarin, Bart Nieuwenhuis, Chin Lik Tan, Joost Verhaagen, Tommaso Pizzorusso, Lisa M. Saksida, Timothy M. Bussey, Hiroshi Kitagawa, Jessica C. F. Kwok, James W. Fawcett. Chondroitin 6-sulphate is required for neuroplasticity and memory in ageing. Molecular Psychiatry, 2021; DOI: 10.1038/s41380-021-01208-9

How Carbon Capture Works

‘Ancient RNA virus epidemics occurred frequently during human evolution’

• Genome adaptations may offer insight into a viral epidemic as far back as 25,000 years.
• Several lines of evidence point to a coronavirus or similar virus that emerged among the ancestors of East Asian people.
• Identifying ancient viral activity may uncover the potential of evolutionary genomic methods to predict and combat future pandemics.

https://www.sciencedirect.com/science/article/pii/S0960982221007946#!

https://www.medicalnewstoday.com/articles/ancient-rna-virus-epidemi...

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15,000-year-old viruses discovered in Tibetan glacier ice

Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.

The findings, published today in the journal Microbiome, could help scientists understand how viruses have evolved over centuries. For this study, the scientists also created a new, ultra-clean method of analyzing microbes and viruses in ice without contaminating it.

The researchers analyzed ice cores taken in 2015 from the Guliya ice cap in western China. The cores are collected at high altitudes—the summit of Guliya, where this ice originated, is 22,000 feet above sea level. The ice cores contain layers of ice that accumulate year after year, trapping whatever was in the atmosphere around them at the time each layer froze. Those layers create a timeline of sorts, which scientists have used to understand more about climate change, microbes, viruses and gasses throughout history.

Researchers determined that the ice was nearly 15,000 years old using a combination of traditional and new, novel techniques to date this ice core.

When they analyzed the ice, they found genetic codes for 33 viruses. Four of those viruses have already been identified by the scientific community. But at least 28 of them are novel. About half of them seemed to have survived at the time they were frozen not in spite of the ice, but because of it.

These viruses have signatures of genes that help them infect cells in cold environments—just surreal genetic signatures for how a virus is able to survive in extreme conditions.

Zhi-Ping Zhong et al, Glacier ice archives nearly 15,000-year-old microbes and phages, Microbiome (2021). DOI: 10.1186/s40168-021-01106-w

https://phys.org/news/2021-07-year-old-viruses-tibetan-glacier-ice....

Surfing science: Dependent on weather, defined by the ocean

Serious wave chasers are by default atmospheric science junkies because there are few, if any, sports that are both dependent on an uncontrollable variable—the weather—and defined by a literal uneven playing field—the ocean.

Waves are created by the way the swells interact with the bottom contours of the ocean, called the break. Beach breaks—like the Olympic site at Tsurigasaki beach—happen because of sandbars, which can shift over time or due to storms.

Competitive surfing in a nutshell is about deciding which wave to take and what move or moves make the best use of what the ocean delivers. Surfers have to remain prepared and continuously observe the waves for their best guess of what wave they will get to ride.

https://phys.org/news/2021-07-surfing-science-weather-ocean.html?ut...

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Through the thin-film glass, researchers spot a new liquid phase

Research published in the Proceedings of the National Academy of Sciences describes a new type of liquid in thin films, which forms a high-density glass. Results generated in this study, conducted by researchers in Penn's Department of Chemistry, demonstrate how these glasses and other similar materials can be fabricated to be denser and more stable, providing a framework for developing new applications and devices through better design.

To make better glasses, researchers have used vapor deposition instead of cooling a liquid to produce a glass. In vapor deposition, a material is changed from a gas into a solid directly. While this method has allowed researchers to create denser types of bulk glasses, it was initially thought that thin glass films made using this method would still have the same liquid-like properties that would lead to degradation and instability.

After running all of the control experiments needed, the researchers were surprised to find that when using vapor deposition, they could access a different type of liquid, with a phase transition to the typical bulk liquid upon heating. A phase transition is when a material changes from from one state (gas, liquid, or solid) into another. "The two liquids have distinct structures, akin to graphene and diamond which are both solids made of carbon but exist in very different solid forms.

There are a lot of interesting properties that came out of nowhere, and nobody had thought that in thin films you would be able to see these phases. It's a new type of material.

Yi Jin el al., "Glasses denser than the supercooled liquid," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2100738118

https://phys.org/news/2021-07-thin-film-glass-liquid-phase.html?utm...

Plastic accumulation in food may be underestimated

A new study has found plastic accumulation in foods may be underestimated. There is also concern these microplastics will carry potentially harmful bacteria such as E. coli, which are commonly found in coastal waters, up the food chain.

Researchers  tested a theory that microplastics covered in a biofilm coating (much like natural algae) were more likely to be ingested by oysters than microplastics that were completely clean. Although the experiment was carried out on oysters under laboratory conditions, scientists believe similar results could be found in other edible marine species that also filter seawater for food.

Up until now, studies to test the impacts of microplastics on marine life have typically used clean, virgin microplastics. However, this is not representative of what happens to microplastics in the marine environment. Bacteria readily colonize microplastics that enter the ocean. In this study, published in Science of the Total Environment, scientists compared the uptake rates of clean microplastics versus microplastics with an E.coli biofilm coating. The results were worrying—oysters contained 10 times more microplastics when exposed to the biofilm coated beads. It is hypothesized that these coated MPs appeared to be more like food to the oysters, explaining their preferential ingestion over clean microplastics.

The scientists say the implications for the food chain are concerning. The ingestion of microplastics is not only bad for the oysters, but it affects human health too. The plastic does not break down in the marine animal and is consumed when we eat it.

The findings in this research give us further insight into the potential harm microplastics are having on the food chain. It demonstrates how we could be vastly underestimating the effect that microplastics currently have. It is clear that further study is urgently needed.

Monica Fabra et al, The plastic Trojan horse: Biofilms increase microplastic uptake in marine filter feeders impacting microbial transfer and organism health, Science of The Total Environment (2021). DOI: 10.1016/j.scitotenv.2021.149217

https://phys.org/news/2021-07-plastic-accumulation-food-underestima...

COVID-19 immunity varies among genders and age groups

As experts continue to learn more about immune responses to COVID-19 and the effectiveness of vaccines, researchers.

 indicates that the level of antibodies changes according to age groups, gender, symptoms, and time elapsed since vaccination. The findings are the latest from the researchers in a series of studies aimed at providing reliable measures on the effectiveness of COVID-19 vaccination. The new study examined the level of antibodies in over 26,000 blood samples taken from COVID-19 convalescents, as well as vaccinated and unvaccinated individuals. In vaccinated individuals, the researchers found differences between women and men in the concentration of antibodies in the blood relative to both age and gender.

In women, the level of antibodies begins to rise from the age of 51, and is higher than the levels found in men of similar age. This phenomenon may be related change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35, and may be related to changes in levels of testosterone and the effect on the immune system.

In young adults, a high concentration of antibodies generally signals a strong healthy functioning immune response, while in older demographics it typically indicates overreaction of the immune system associated with severe illness. In general, young adults were found to have a higher level of antibodies sustained for a longer period of time compared to older vaccinated persons. The findings further validate existing evidence that, depending on age, higher antibody count isn't necessarily equivalent to higher rates of recovery.

Furthermore, the study found that the immune response of vaccinated individuals (after two doses) is much stronger than that of people who have recovered from COVID-19. The findings show that vaccinated individuals have four times the level of antibodies compared to convalescents.

https://www.medrxiv.org/content/10.1101/2021.07.07.21259499v1

https://english.tau.ac.il/news/covid_immunity_varies

Innovative Gene Therapy ‘Reprograms’ Cells to Reverse Neurological Deficiencies

A Lagoon in Argentina Turned Bright Pink, But This Time The Reason Is Unnatural

Acoustic Manipulation off a Reflective Surface

The Universe has an average colour – and it’s called cosmic latte

In a 2002 study, astronomers found that the light coming from galaxies (and the stars within them) – alongside all the visible clouds of gas and dust in the Universe – when averaged, would produce an ivory colour very close to white. They named this colour ‘cosmic latte’.

The ‘beigeness’ of the Universe is because there are slightly more regions that produce red, yellow and green light than those that produce blue. Averaged over the entire sky, however, this beige colour is diluted and appears almost, but not entirely, black.

https://www.sciencefocus.com/space/universe-average-colour-cosmic-l...

When our defences turn on us

When the body becomes the target of its own defensive arsenal, medicine must step in. This Nature Outlook explores why autoimmune disease is around three times more common in women than in men, the genetic variants that increase the risk of autoimmunity and how the microbes in our gut might sometimes be to blame. It also reveals how the possible links between long COVID and the immune system might finally prove that viruses can spark autoimmune disease.

Nature | Full collection

'Good cholesterol' may protect liver

 The body's so-called good cholesterol may be even better than we realize. New research from Washington University School of Medicine in St. Louis suggests that one type of high-density lipoprotein (HDL) has a previously unknown role in protecting the liver from injury. This HDL protects the liver by blocking inflammatory signals produced by common gut bacteria. The study was published July 23 in the journal Science. HDL is mostly known for mopping up cholesterol in the body and delivering it to the liver for disposal. But in the new study, the researchers identified a special type of HDL called HDL3 that, when produced by the intestine, blocks gut bacterial signals that cause liver inflammation. If not blocked, these bacterial signals travel from the intestine to the liver, where they activate immune cells that trigger an inflammatory state, which leads to liver damage. Even though HDL has been considered good cholesterol,’ drugs that increase overall HDL levels have fallen out of favor in recent years because of clinical trials that showed no benefit in cardiovascular disease.  study suggests that raising levels of this specific type of HDL, and specifically raising it in the intestine, may hold promise for protecting against liver disease, which, like heart disease, also is a major chronic health problem.

Any sort of intestinal damage can impact how a group of microbes called Gram-negative bacteria can affect the body. Such microbes produce an inflammatory molecule called lipopolysaccharide that can travel to the liver via the portal vein. The portal vein is the major vessel that supplies blood to the liver, and it carries most nutrients to the liver after food is absorbed in the intestine. Substances from gut microbes may travel along with nutrients from food to activate immune cells that trigger inflammation. In this way, elements of the gut microbiome may drive liver disease, including fatty liver disease and liver fibrosis, in which the liver develops scar tissue.

https://researchnews.cc/news/8017/-Good-cholesterol--may-protect-li...

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Fingertip-powered wearable

Physicists Have Figured Out How We Could Make Antimatter Out of Light

A new study by scientists has demonstrated how researchers may be able to create an accelerating jet of antimatter from light.

A team of physicists has shown that high-intensity lasers can be used to generate colliding gamma photons – the most energetic wavelengths of light – to produce electron-positron pairs. This, they say, could help us understand the environments around some of the Universe's most extreme objects: neutron stars.

The process of creating a matter-antimatter pair of particles – an electron and a positron – from photons is called the Breit-Wheeler process, and it's extremely difficult to achieve experimentally.

The probability of it taking place when two photons collide is very small. You need very high-energy photons, or gamma rays, and a lot of them, in order to maximize the chances of observation.

We don't yet have the capability to build a gamma-ray laser, so the photon-photon Breit-Wheeler process currently remains experimentally unachieved. But a team of physicists led by Yutong He of the University of California, San Diego (UC San Diego) has proposed a new workaround that, according to their simulations, could actually work.

It consists of a plastic block, carved with a pattern of criss-crossing channels on the micrometer scale. Two powerful lasers, one on either side of the block, fire strong pulses at this target.

"When the laser pulses penetrate the sample, each of them accelerates a cloud of extremely fast electrons. 

These two electron clouds then race toward each other with full force, interacting with the laser propagating in the opposite direction."

The resulting collision is so energetic that it produces a cloud of gamma photons. These gamma photons should collide with each other to produce electron-positron pairs,  in accordance with Einstein's theory of general relativity.

Even more excitingly, this process should generate powerful magnetic fields that collimate the positrons (rather than the electrons) into strongly accelerated, jet-shaped beams. In a distance of just 50 micrometers, the researchers found, the acceleration should increase the energy of the particles to one gigaelectronvolt.

Using a complex computer simulation, the researchers tested their model, and found that it should work, even when using less powerful lasers than previous proposals.

Not only would the collimation and acceleration of the positron beam improve the detection rate of the particles, but it bears a strong similarity to the powerful collimated particle jets beamed out by strongly magnetic, rapidly rotating neutron stars known as pulsars.

Scientists believe that processes that take place close to these stars could result in clouds of gamma radiation, similar to their proposed experiment.

https://www.nature.com/articles/s42005-021-00636-x

https://www.sciencealert.com/physicists-have-figured-out-how-we-cou...

The Hidden Beauty of Rainbows

Earth's 'vital signs' worsening as humanity's impact deepens

The global economy's business-as-usual approach to climate change has seen Earth's "vital signs" deteriorate to record levels, an influential group of scientists said recently, warning that several climate tipping points were now imminent.

The researchers, part of a group of more than 14,000 scientists who have signed on to an initiative declaring a worldwide climate  emergency, said that governments had consistently failed to address the root cause of climate change: "the overexploitation of the Earth".

Of 31 "vital signs"—key metrics of planetary health that include greenhouse gas emissions, glacier thickness, sea-ice extent and deforestation—they found that 18 hit record highs or lows.

For example, despite a dip in pollution linked to the pandemic, levels of atmospheric CO2 and methane hit all-time highs in 2021.

Greenland and Antarctica both recently showed all-time low levels of ice mass, and glaciers are melting 31 percent faster than they did just 15 years ago, the authors said.

Both ocean heat and global sea levels set new records since 2019, and the annual loss rate of the Brazilian Amazon reached a 12-year high in 2020.

Echoing previous research, they said that forest degradation linked to fire, drought and logging was causing parts of the Brazilian Amazon to now act as a source of carbon, rather than absorb the gas from the atmosphere.

Livestock such as cows and sheep are now at record levels, numbering more than four billion and with a mass exceeding that of all humans and wild land mammals combined, they said.

We need to respond to the evidence that we are hitting climate tipping points with equally urgent action to decarbonise the global economy and start restoring instead of destroying nature, they stressed.

The researchers said there was "mounting evidence that we are nearing or have already crossed" a number of climate tipping points.

https://academic.oup.com/bioscience/advance-article/doi/10.1093/bio...

https://phys.org/news/2021-07-earth-vital-worsening-humanity-impact...

Motivation depends on how the brain processes fatigue

How do we decide whether or not an activity which requires work is 'worth the effort'? Researchers  have shown that the willingness to work is not static, and depends upon the fluctuating rhythms of fatigue.

Fatigue—the feeling of exhaustion from doing effortful tasks—is something we all experience daily. It makes us lose motivation and want to take a break. Although scientists understand the mechanisms the brain uses to decide whether a given task is worth the effort, the influence of fatigue on this process is not yet well understood.

The research team conducted a study to investigate the impact of fatigue on a person's decision to exert effort. They found that people were less likely to work and exert effort—even for a reward—if they were fatigued. The results are published in Nature Communications.

Intriguingly, the researchers found that there were two different types of fatigue that were detected in distinct parts of the brain. In the first, fatigue is experienced as a short-term feeling, which can be overcome after a short rest. Over time, however, a second, longer term feeling builds up, stops people from wanting to work, and doesn't go away with short rests.

Tanja Müller et al, Neural and computational mechanisms of momentary fatigue and persistence in effort-based choice, Nature Communications (2021). DOI: 10.1038/s41467-021-24927-7

Dark mode may not save battery life as much as anticipated

When Android and Apple operating system updates started giving users the option to put their smartphones in dark mode, the feature showed potential for saving the battery life of newer phones with screens that allow darker-colored pixels to use less power than lighter-colored pixels.

But dark mode is unlikely to make a big difference to battery life with the way that most people use their phones on a daily basis, says a new study by  researchers.

That doesn't mean that dark mode can't be helpful, though.

 Researchers found that switching from light mode to dark mode saves only 3%-9% power on average for several different OLED smartphones.

This percentage is so small that most users wouldn't notice the slightly longer battery life. But the higher the brightness when switching from light mode to dark mode, the higher the energy savings.

Pranab Dash et al, How much battery does dark mode save?, Proceedings of the 19th Annual International Conference on Mobile Systems, Applications, and Services (2021). DOI: 10.1145/3458864.3467682

https://techxplore.com/news/2021-07-dark-mode-battery-life.html?utm...

More carbon emissions will kill more people; here's how many

A just-published study coins a new metric: the "mortality cost of carbon." That is, how many future lives will be lost—or saved—depending on whether we increase or decrease our current carbon emissions. If the numbers hold up, they are quite high. The study was published recently in the journal Nature Communications.

Researchers saw a major gap in current estimates of the social cost of carbon—the dollar figure that economists attach to each ton of emissions, based on future damages it is expected to inflict. A complex and highly malleable number, the social cost of carbon underpins how governments worldwide formulate climate policies,  by suggesting how much we should be willing to pay today in order to avert damages in the future. Yet, while recent studies project that climate change will cause millions of premature deaths, current estimates of the social cost of carbon rely on outdated research that does not include those projections. Scientists now attempts to add in the new data.

Based on the decisions made by individuals, businesses or governments, this tells you how many lives will be lost, or saved. It quantifies the mortality impact of those decisions. It brings this question down to a more personal, understandable level.

Assuming that emissions continue to increase on their current high path, researchers came up with a number: 2.26×10^-4, or 0.000226 excess deaths this century per metric ton of carbon dioxide emitted beyond the current rate of emissions. That is: For every 4,434 metric tons of CO₂ that we add beyond the 2020 rate of emissions, we will kill one person. 

This implies that we must cut emissions in a big way now, and reach full decarbonization by 2050. The result would be only 2.4 degrees of warming by 2100. As a result, by scientists' calculation, excess deaths would drop to 9 million by 2100—a saving of 74 million lives.

All these figures are subject to political finagling.

https://news.climate.columbia.edu/2021/07/29/more-carbon-emissions-...

New exotic matter particle, a tetraquark, discovered

Yesterday  the LHCb experiment at CERN has presented a new discovery at the European Physical Society Conference on High Energy Physics (EPS-HEP). The new particle discovered by LHCb, labeled as T_cc⁺, is a tetraquark—an exotic hadron containing two quarks and two antiquarks. It is the longest-lived exotic matter particle ever discovered, and the first to contain two heavy quarks and two light antiquarks.

Quarks are the fundamental building blocks from which matter is constructed. They combine to form hadrons, namely baryons, such as the proton and the neutron, which consist of three quarks, and mesons, which are formed as quark-antiquark pairs. In recent years a number of so-called exotic hadrons—particles with four or five quarks, instead of the conventional two or three—have been found. The present  discovery is of a particularly unique exotic hadron.

The new particle  contains two charm quarks and an up and a down antiquark. 

https://home.cern/news/news/physics/twice-charm-long-lived-exotic-p...

Water transformed into shiny, golden metal

Electrons from a droplet of sodium and potassium turn water into a metallic material that conducts electricity.

Researchers have transformed water into a metallic material by forming a thin layer of water around electron-sharing alkali metals. The water stayed in a metallic state for only a few seconds, but the experiment did not require the high pressures that are normally needed to turn non-metallic materials into electrically conductive metals. Scientists say that seeing the water take on a golden shine was a highlight of their career, and a reminder that science can be fun.

Study: COVID-19 does not enter DNA

Researchers are refuting claims that COVID-19 corona virus can enter a person's DNA.

The researchers say the claims have led to "scaremongering" and people should not hesitate to be vaccinated.

Research published in Cell Reports showed there was no evidence of COVID-19—or the Pfizer or AstraZeneca vaccines—entering DNA.

The evidence refutes this concept being used to fuel vaccine hesitancy.

Scientists conducted the research to assess now widely spread findings, published in the Proceedings of the National Academy of Sciences, suggesting positive COVID-19 tests long after recovery are due to the virus being incorporated into DNA.

Researchers now looked into their claims that the human cells and machinery turned COVID-19 RNA into DNA, causing permanent mutations.

They assessed the claims in cells grown in the laboratory, conducted DNA sequencing and found no evidence of COVID-19 in DNA.

From a public health point of view, scientists affirmed  that there are no concerns that the virus or vaccines can be incorporated into human DNA.

Nathan Smits et al, No evidence of human genome integration of SARS-CoV-2 found by long-read DNA sequencing, Cell Reports (2021). DOI: 10.1016/j.celrep.2021.109530

https://medicalxpress.com/news/2021-07-covid-dna.html?utm_source=nw...

Solar-powered microbes to feed the world?

Researchers show that protein from microbes uses a fraction of the resources of conventional farming

An international research team has shown that using solar-panels to produce microbial protein -- which is rich not just in proteins but also in other nutrients -- is more sustainable, efficient and environmentally friendly than growing conventional crops. This method uses solar energy, land, nutrients, and carbon dioxide from the air.

Using computer simulations drawing directly from laboratory results, the researchers modelled large-scale microbial food production facilities, which use solar energy, air, water, and nutrients to grow microbes. The protein-rich biomass is harvested and processed, and the resulting powder can be used as feed for animals, or as food for people. The study carried out an analysis of the energy requirements for each step, from the very start to the end product, taking into account: electricity generation (from solar panels), electrochemical production of energy-rich substrate for the microbes, microbe cultivation, harvesting, and processing the protein-rich biomass. Several types of microbes and growth strategies were compared in order to identify the most efficient.

The study found that for each kilo of protein produced, solar-powered microbes require only 10% of the land area compared to even the most efficient plant crop -- soybean. The study calculated that even in northern climates with less sunshine, the yields of solar-powered microbial foods could far outproduce staple crops, while minimizing water and fertilizer use. Importantly, this production could also be located in regions not suitable for agriculture, such as deserts.

Dorian Leger, Silvio Matassa, Elad Noor, Alon Shepon, Ron Milo, Arren Bar-Even. Photovoltaic-driven microbial protein production can use land and sunlight more efficiently than conventional crops. Proceedings of the National Academy of Sciences, 2021; 118 (26): e2015025118 DOI: 10.1073/pnas.2015025118

https://www.sciencedaily.com/releases/2021/07/210730104303.htm

Fewer citations for female authors

Research papers published by women in elite medical journals are half as likely to be cited as are similar articles authored by men, a study of citation data has found. The work, which looked at more than 5,554 articles published between 2015 and 2018, “shows just how much impact unconscious biases can have”, says oncologist Reshma Jagsi. Citations are considered a key measure of a paper’s importance, and are often taken into account by those who make hiring and funding decisions.

Gender Disparity in Citations in High-Impact Journal Articles

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/278161...

Eternal Change for No Energy: A Time Crystal Finally Made Real

“Neuroprosthesis” Restores Words to Man with Paralysis

Why wildfires have gotten worse -- and what we can do about it

What causes déjà vu?

A Fully Autonomous Swarm of Gas-Seeking Nano Quadcopters in Cluttered Environments

Researchers have developed a swarm of autonomous, tiny drones that is able to localize gas sources in unknown, cluttered environments. Bio-inspired AI allows the drones to tackle this complex task without any external infrastructure.

Some birds steal hair from living mammals

A new paper in the journal Ecology documents this phenomenon, which the authors call “kleptotrichy,” from the Greek roots for “theft” and “hair.” The authors found only a few descriptions of the behavior in the scientific literature but came up with dozens more examples in online videos posted by birders and other bird enthusiasts. In almost all the videorecorded cases, the thief is a titmouse plucking hair from a cat, dog, human, raccoon, foxes, or in one case, porcupine.

A Bathing Suit That Doesn’t Get Wet

Mice treated with this cytokine lose weight by 'sweating' fat

 Treating obese mice with the cytokine known as TSLP led to significant abdominal fat and weight loss compared to controls, according to new research published recently  in Science.

The fat loss was not associated with decreased food intake or faster metabolism. Instead, the researchers discovered that TSLP stimulated the immune system to release lipids through the skin’s oil-producing sebaceous glands.

This was a completely unforeseen finding, but researchers have demonstrated that fat loss can be achieved by secreting calories from the skin in the form of energy-rich sebum.

To examine whether TSLP could potentially play a role in the control of oil secretion in humans, the researchers then examined TSLP and a panel of 18 sebaceous gland-associated genes in a publicly-available dataset. This revealed that TSLP expression is significantly and positively correlated with sebaceous gland gene expression in healthy human skin.

The study authors write that, in humans, shifting sebum release into “high gear” could feasibly lead to the “sweating of fat” and weight loss.

Ruth Choa, Junichiro Tohyama, Shogo Wada, Hu Meng, Jian Hu, Mariko Okumura, Rebecca M. May, Tanner F. Robertson, Ruth-Anne Langan Pai, Arben Nace, Christian Hopkins, Elizabeth A. Jacobsen, Malay Haldar, Garret A. FitzGerald, Edward M. Behrens, Andy J. Minn, Patrick Seale, George Cotsarelis, Brian Kim, John T. Seykora, Mingyao Li, Zoltan Arany, Taku Kambayashi. Thymic stromal lymphopoietin induces adipose loss through sebum hypersecretion. Science, 2021; 373 (6554): eabd2893 DOI: 10.1126/science.abd2893

https://www.sciencedaily.com/releases/2021/07/210729143412.htm

Lake Huron Sinkhole gives Clues to Oxygen Production on Early Earth

An international research team is proposing that increasing day length on the early Earth may have boosted the amount of oxygen released by photosynthetic cyanobacteria, thereby shaping the timing of Earth’s oxygenation. The rise of oxygen levels early in Earth’s history paved the way for life as we know it. The team's conclusion was inspired by a study of present-day microbial communities growing under extreme conditions at the bottom of a submerged Lake Huron sinkhole, about 80 feet below the water’s surface.

 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...

Muscles are important, but stiff tendons are the secret ingredient for high-speed performance

You might be surprised to learn that most of the explosive power displayed by  elite athletes doesn't come from their muscles, or even from their minds—it comes from somewhere else.

Muscles are important, but the real secret is using training and technique to store and reuse elastic energy in the best way possible—and that means making the most of your tendons. By understanding how this power is produced, we can help people walk, run and jump into older age and how to walk again after injury or illness.

Muscles are remarkably powerful. The average human calf muscle weighs less than 1 kilogram, but can lift a load of 500kg. In some cases, our calf muscles have even been shown to handle loads approaching a ton(1,000kg)!

But muscles have a major performance issue: they can't produce much force when they're shortening at high speed. In fact, when we move at our fastest, muscles can't theoretically shorten fast enough to help us at all—so how is it that we can move so quickly?

part 1

**

Muscles are strong, but slow

Muscles produce most of their force through the interactions of two proteins: actin and myosin. The rotating, globular "head" region of the long myosin filament attaches to the rod-like actin to pull it along in a sweeping motion, like an oar producing force to pull a boat along the water. So actin and myosin filaments form powerful mini motors.

Trillions of these mini motors together the large forces we need every day to walk upstairs, carry our shopping bags, or take the lid off a jar.

The head region of myosin is only 20 nanometres long. It's so small that there's no point comparing its size to a human hair, because it would barely even cross a handful of DNA molecules laid side by side.

Because it's so short and only pulls actin a small distance in each stroke, a large number of strokes are needed to shorten a muscle by any distance. It's like using first gear to get up a hill in a car or on a bike—good for force, but not for speed.

And the faster the muscle shortens, the less time each myosin is attached to actin, which reduces force even further. At a certain shortening speed, muscles can't produce any force at all.

We can measure the power athletes produce during running and jumping, and we can estimate the power a muscle should produce by its size and the type of fibers it contains. When we compare these two values, we find that muscles can't even produce half the power generated in sprinting or vertical jumping. And in overarm throwing, muscles can produce only15% of the total power.

So if the muscles aren't producing the power to move a body at high speed, where is it coming from? Humans, like most other animals on Earth, make use of an "energy return system": something that can store energy and release it rapidly when needed.

Our energy return systems are made of a relatively long, stretchy tendon attached to a strong muscle. When the muscle produces force it stretches the tendon, storing elastic energy. The subsequent recoil of the tendon then generates a power far superior to our muscles. Our tendons are power amplifiers.

There are several techniques we can use to increase energy storage. The most important is to first move in the opposite direction to the desired movement (a "countermovement") so the muscle force is already high when the proper movement begins. Most of us learn this strategy when we're young, when we first dip down before we jump upwards, or we draw our bat or racquet backwards before swinging it forwards.

The technique we use is key to maximizing our elastic potential, and Olympic athletes spend years trying to optimize it.

Tendons that are stiffer or stretched further will store more energy and then recoil with greater power. During running, the greatest power is produced at the ankle joint, so it makes sense that sprint runners and the best endurance runners have stiffer Achilles' tendons than us mere mortals.

They also have the muscle strength to stretch them. We haven't yet accurately measured the stiffness of shoulder tendons in athletes, but we might assume they are built similarly.

part 2

The capacity to store and release elastic energy is partly determined by genetics, but it's also something we can improve through training. Not only can training improve your technique, heavy strength training and other methods can also make your tendons stiffer.

As we develop from childhood to adulthood, we learn to make better use of elastic energy to produce more power and use it more efficiently. As we age further, our tendon stiffness and power output decrease, and it costs us more energy to move.

People with less stiffness in their Achilles' tendon (and the accompanying lower strength in the calf muscles) have slower walking speeds. As walking speed is strongly associated with mortality and morbidity in the elderly, maintaining tendon stiffness may be important to our health and longevity.

The greatest power during walking, running and jumping is produced at the ankle joint. This is an important target for athletes, but also for anyone who wants to maintain their walking capacity as they age.

Good ways to keep your ankle muscles conditioned include calf raises on a step, squat to calf raise exercises, and walking up and down hills whenever you get the chance.

If you feel game, you might even join a gym and enjoy the numerous ways to strengthen your calf and Achilles' tendon, and lots of other muscles too.

https://medicalxpress.com/news/2021-08-muscles-important-stiff-tend...

https://theconversation.com/muscles-are-important-but-stiff-tendons...

part 3

Male fertility is declining, environmental toxins could be a reason

A wide range of factors—from obesity to hormonal imbalances to genetic diseases—can affect fertility. For many men, there are treatments that can help. But starting in the 1990s, researchers noticed a concerning trend. Even when controlling for many of the known risk factors, male fertility appeared to have been declining for decades. In 1992, a study found a global 50% decline in sperm counts in men over the previous 60 years. Multiple studies over subsequent years confirmed that initial finding, including a 2017 paper showing a 50% to 60% decline in sperm concentration between 1973 and 2011 in men from around the world. The science is consistent: Men today produce fewer sperm than in the past, and the sperm are less healthy. The question, then, is what could be causing this decline in fertility. Scientists have known for years that, at least in animal models, environmental toxic exposure can alter hormonal balance and throw off reproduction. Researchers can't intentionally expose human patients to harmful compounds and measure outcomes, but we can try to assess associations. As the downward trend in male fertility emerged, I and other researchers began looking more toward chemicals in the environment for answers. This approach doesn't allow us to definitively establish which chemicals are causing the male fertility decline, but the weight of the evidence is growing. A lot of this research focuses on endocrine disrupters, molecules that mimic the body's hormones and throw off the fragile hormonal balance of reproduction. These include substances like phthalates—better known as plasticizers—as well as pesticides, herbicides, heavy metals, toxic gases and other synthetic materials. Plasticizers are found in most plastics—like water bottles and food containers—and exposure is associated with negative impacts on testosterone and semen health.Herbicides and pesticides abound in the food supply and some—specifically those with synthetic organic compounds that include phosphorus—are known to negatively affect fertility. Air pollution surrounds cities, subjecting residents to particulate matter, sulfur dioxide, nitrogen oxide and other compounds that likely contribute to abnormal sperm quality. Radiation exposure from laptops, cellphones and modems has also been associated with declining sperm counts, impaired sperm motility and abnormal sperm shape. Heavy metals such as cadmium, lead and arsenic are also present in food, water and cosmetics and are also known to harm sperm health. Endocrine-disrupting compounds and the infertility problems they cause are taking a significant toll on human physical and emotional health. And treating these harms is costly.

https://theconversation.com/male-fertility-is-declining-studies-sho...

https://medicalxpress.com/news/2021-08-male-fertility-declining-env...

**

Deficiency in how gut microbiome-produced substances are detected in high blood pressure

In a new study  scientists have found that microbial genetic pathways are different in people suffering from hypertension.

The research also found that those with hypertension also have a deficiency in a newly identified target gene that senses gut microbiota-derived metabolites that lower BP.

If left untreated, hypertension, also referred to as high BP, can lead to stroke and, myocardial infarction, the main causes of death globally. Long-term, hypertension causes a stiffening of the arteries and the muscles of the heart, leading to heart failure. This is important as the research team also found in another recently published study that patients with heart failure, for which hypertension is a major risk factor, have a distinct gut microbiome composition.

The research team assessed human gut microbiota in the setting of high blood-pressure levels and heart failure to better understand the complex nature of these diseases. Changes in gut microbiome were particularly associated with bacteria that are known to produce short-chain fatty acids, substances their team has previously shown to ameliorate blood pressure and heart disease in mice.

The researchers found that the gut microbiome was mostly similar between normotensive and essential hypertensive groups, but the gut microbial gene pathways were different, suggesting major differences in the function of the microbiota.

They also found that hypertensive subjects have a deficiency in a new target gene that senses gut microbiota derived metabolites that lower blood pressure.

 Michael Nakai et al, Essential Hypertension Is Associated With Changes in Gut Microbial Metabolic Pathways, Hypertension (2021). DOI: 10.1161/HYPERTENSIONAHA.121.17288

Anna L. Beale et al, The Gut Microbiome of Heart Failure With Preserved Ejection Fraction, Journal of the American Heart Association (2021). DOI: 10.1161/JAHA.120.020654

https://medicalxpress.com/news/2021-08-deficiency-gut-microbiome-pr...

Traumatic brain injury research

How sex cells get the right genetic mix