Preserve a Strawberry Forever?

First steerable catheter developed for brain surgery

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

The steerable catheter was successfully tested in pigs .

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

Rattlesnake rattles trick human ears

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

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

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

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

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

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

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

Scientists harness human protein to deliver molecular medicines to cells

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

part1 

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

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

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

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

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

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

part2

Experimental confirmation of wave-particle duality

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

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

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

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

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

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Alternative cement with low carbon footprint developed

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

Why sports concussions are worse for women

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

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

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

Part 2

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

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

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

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

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

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

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

Like a global pandemic.

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

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

Scientists then and now

How Science Affects Your Ice Cream

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

Swimming robot gives fresh insight into locomotion and neuroscience

Hubble Captures a Stunning 'Einstein Ring'

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Food allergy and intolerance: the differences

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

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

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

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

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

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

part 1

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

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

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

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

part 2

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

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

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

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

One material with two functions could lead to faster memory

In a step toward a future of higher performance memory devices, researchers  have developed a new device that needs only a single semiconductor known as perovskite to simultaneously store and visually transmit data.

By integrating a light-emitting electrochemical cell with a resistive random-access memory that are both based on perovskite, the team achieved parallel and synchronous reading of data both electrically and optically in a 'light-emitting memory.'

Meng-Cheng Yen et al, All-inorganic perovskite quantum dot light-emitting memories, Nature Communications (2021). DOI: 10.1038/s41467-021-24762-w

https://techxplore.com/news/2021-08-material-functions-faster-memor...

Study: Benefits outweigh risks for autonomous vehicles—as long as you regulate them

An interdisciplinary panel of experts has assessed the risks and potential benefits associated with deploying autonomous vehicles (AVs) on U.S. roads and predicts that the benefits will substantially outweigh potential harms—but only if the AVs are well regulated.

Veljko Dubljevic et al, Toward a rational and ethical sociotechnical system of autonomous vehicles: A novel application of multi-criteria decision analysis, PLOS ONE (2021). DOI: 10.1371/journal.pone.0256224

https://techxplore.com/news/2021-08-benefits-outweigh-autonomous-ve...

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First video evidence of tortoises hunting birds / Curr. Biol., Aug. 23, 2021 (Vol. 31, Issue 16)

How the brain’s internal ‘hourglass’ controls our need for sleep 

Although sleep is absolutely vital, until now it hasn’t been known which structure of the brain tells us when we are tired. But  a  recent study has shown in laboratory mice that the cerebral cortex, which is responsible for the most complex brain functions – including perception, language, thought and episodic memory – helps us track our need for sleep.

To ensure that we get enough sleep, our brain uses two tools: a clock and an hourglass. Our biological clock helps us to keep a 24-hour rhythm. It’s controlled by the suprachiasmatic nucleus, which is a small area deep in our brain. This coordinates the rhythms of various organs, and helps us to sleep at night and wake up in the morning.

But our biological clock is only a guide – it’s not the main regulator of sleep. Instead, the brain uses an “hourglass” to keep track of the accumulated amount of sleep we’ve had. This hourglass slowly empties while we’re awake and refills while we’re asleep. This is why we’re able to stay awake longer when we need to, and make up this sleep deficit later by napping or sleeping longer the next night.

part 1

Some researchers have proposed that the brain does not measure the time we have spent awake – rather, it tracks how hard the brain works while we’re awake, and adjusts the amount of sleep we need accordingly. Research in support of this theory has found that individual areas of cortex can briefly switch off when overworked, even while the rest of the brain is still awake. This temporary shutdown of individual brain areas is termed “local sleep” and thought to be a mechanism that allows the brain’s cells to recover. While a person might not notice it, such a localised shutdown can profoundly affect someone’s performance – for example while driving a car.

But our brain would be very inefficient if individual parts of the cortex often went into local sleep whenever they felt they needed to. This is why it’s thought that the cortex may not only generate local sleep, but also activate the main sleep centres.

. Suppressing sleep might be dangerous, as sleep serves several essential, but still poorly understood, functions in our body and brain – such as memory processing, and making sure our immune system and metabolism function properly. But for many of us who struggle to feel tired and fall asleep, manipulating the cortex could become a way of triggering sleep when we’re struggling to nod off.

https://theconversation.com/feeling-tired-heres-how-the-brains-inte...

part 2

Some Rare Diamonds Form Out of The Remains of Once-Living Creatures

New research has discovered that two different types of rare diamonds share a common origin story – the recycling of once-living organisms over 400 kilometers (250 miles) below the surface.

There are three main types of natural diamonds. The first are lithospheric diamonds, which form in the lithospheric layer around 150 to 250 kilometers (93 - 155 miles) below the surface of Earth. These are by far the most common.

Then there are two rarer types - oceanic and super-deep continental diamonds.

Oceanic diamonds are found in oceanic rocks, while deep continental diamonds are those formed between 300 and 1,000 kilometers (186 and 621 miles) below the surface of Earth.

 oceanic and super-deep continental diamonds seem pretty different. Because variation in a carbon isotope signature called δ¹³C (delta carbon thirteen) can be used to determine whether the carbon has an organic or inorganic origin, past researchers have suggested that oceanic diamonds originally formed from organic carbon that was once within living beings.

Super-deep continental diamonds, on the other hand, have an extremely variable amount of δ¹³C. It's hard to tell whether they're made of organic carbon or not.

But in this new paper, led by Curtin University geologist Luc Doucet, the team found that the cores of super-deep continental diamonds have a similar δ¹³C composition. Surprisingly, this means that, like oceanic diamonds, these gems also contain the remains of once-living creatures.

https://www.nature.com/articles/s41598-021-96286-8

https://www.sciencealert.com/rare-diamonds-are-actually-made-of-onc...

A host  enzyme allows viruses to ride roughshod in the liver, paving the way to cancer

Chronic viral infections in the liver can lead to organ dysfunction and ultimately to liver tumors in a progression invariably characterized by viruses that proliferate free of immune system restraints.

Although it has been known for decades that chronic viral infection of the liver can lead to cancer, medical investigators have only now begun to fully appreciate how the disruption of molecular signaling sets the stage for virus-induced liver cancer.

In an elegant series of cellular studies, scientists have found that a transmembrane enzyme (a protein embedded in the cell with active portions above and below the cell surface) plays a powerful role in damaging liver cells.

That enzyme goes by the name of hepsin, and is produced by the host. It increases vulnerability to liver cancer because it's a noteworthy turncoat—a biological traitor—when active in the milieu of a viral infection. Although the research team saw the damaging activity in the lab when two types of viruses, Sendai and herpes, were studied, the major global health crisis involving liver infections and cancer are centered squarely on hepatitis B and C.

Hepsin, as it turns out, doesn't even mess with the viruses themselves to create havoc in the liver; it irrevocably damages a protective protein called STING. Once STING is crippled, viruses are free to run roughshod through the liver.

Fu Hsin et al, The transmembrane serine protease hepsin suppresses type I interferon induction by cleaving STING, Science Signaling (2021). DOI: 10.1126/scisignal.abb4752

https://medicalxpress.com/news/2021-08-turncoat-protein-viruses-rou...

Microbiome-based therapies: Genetically engineered good bacteria could aid in combating disease

Our bodies are home to several bacterial species that help us maintain our health and wellbeing. Thus, engineering these good bacteria to alter the activity of genes gone awry, either by turning them down or by activating them, is a promising approach to improve health and combat diseases.

n a study published in the journal Nature Communications, researchers at Texas A&M University have developed a sophisticated, programmable gene silencing system that might have future therapeutic implications.

Using chemical triggers, the researchers showed that lab-engineered bacteria Escherichia coli (E. coli) could be induced to make gene products to suppress certain traits in Caenorhabditis elegans (C. elegans), a roundworm that consumes this strain of bacteria as food. Similarly, the researchers noted that in the future, symbiotic bacteria within the human microbiome could be engineered to sense, record and deliver therapeutics to improve health and wellbeing.

Here, researchers have used bacteria to tweak the gene expression in another organism, which is a proof of concept that bacteria living in symbiosis with humans could be engineered to modulate human physiology and treat disease.

Baizhen Gao et al, Programming gene expression in multicellular organisms for physiology modulation through engineered bacteria, Nature Communications (2021). DOI: 10.1038/s41467-021-22894-7

Part 1

In addition to the genes that are tightly bundled up into chromosomes, bacteria and certain other microbes have other shorter, circular strands of DNA, called plasmids. Not only can plasmids replicate, they also have much fewer genes than their chromosomal counterparts. These properties make plasmids easier to manipulate with genetic tools. In particular, segments of DNA from other organisms, known as transgenes, can be inserted into bacterial plasmids.

Further, as plasmids replicate, multiple copies of the transgenes are produced. For example, if the human gene for making insulin is inserted into a plasmid, then as the bacteria replicate, more copies of the plasmids and consequently insulin genes are made. And so, when these genes are expressed, more insulin is produced. Alternately, plasmids can be extracted from the bacteria and used as vehicles to insert transgenes into the genome of other cells to alter traits in those cells.

The researchers noted that while these types of genetic manipulations have been routine in mammalian cells and other simple microbes, they have often been difficult to orchestrate in more complex, multicellular organisms. To overcome these hurdles, Sun and her team selected a bacteria-host pair that have a symbiotic relationship. In particular, they chose the soil-dwelling worm, C. elegans, that feeds on E. coli.

First, they inserted a transgene into E. coli's plasmid that can interfere with a genetically engineered strain of C. elegans, which has the ability to glow fluorescently green. Then, using a chemical, they induced the plasmid to express the green fluorescence-suppressing gene. Last, they fed the bacteria to C. elegans and found that only those C. elegans that consumed the E. coli with the transgene stopped glowing green.

In addition, Sun and her team programmed E. Coli to produce gene products with different "AND" and "OR" logic gates. Put simply, gene products could be selectively produced only by the combined action of two or more genes, like the mathematical "AND" operation, or if any one gene was expressed, like the mathematical "OR" operation. Once again, using chemical triggers, the researchers initiated an "AND" or "OR" combination of gene expression in the E. Coli needed to silence twitching behavior in C. elegans after the worms fed on the bacteria.

Sun said that their bacteria-based gene silencing system could be easily extended to other living systems for applications in pest control, plant growth promotion and veterinary disease diagnosis.

"Bacteria have a symbiotic relationship with many species, affecting their hosts' metabolism, immunity and behavior," said Sun. "Here, we have taken advantage of the symbiosis between bacteria and a relatively complex organism to engineer a programmable genetic tool that can influence host physiology in a positive way."

https://phys.org/news/2021-08-genetically-good-bacteria-aid-combati...

part 2

High cholesterol fuels cancer by fostering resistance to a form of cell death

Chronically high cholesterol levels are known to be associated with increased risks of breast cancer and worse outcomes in most cancers, but the link has not been fully understood.

In a new study  appearing online Aug. 24 in the journal Nature Communications, a research team led by the Duke Cancer Institute has identified the mechanisms at work, describing how breast cancer cells use cholesterol to develop tolerance to stress, making them impervious to death as they migrate from the original tumor site.

Most cancer cells die as they try to metastasize—it's a very stressful process. The few that don't die have this ability to overcome the cell's stress-induced death mechanism. researchers now  found that cholesterol was integral in fueling this ability.

In the current study using cancer cell lines and mouse models, the  researchers found that migrating cancer cells gobble cholesterol in response to stress. Most die.

But in the what-doesn't-kill-you-makes-you-stronger motif, those that live emerge with a super-power that makes them able to withstand ferroptosis, a natural process in which cells succumb to stress. These stress-impervious cancer cells then proliferate and readily metastasize.

The process appears to be used not only by ER-negative breast cancer cells, but other types of tumors, including melanoma. And the mechanisms identified could be targeted by therapies.

https://www.nature.com/articles/s41467-021-25354-4

Dysregulated cholesterol homeostasis results in resistance to 2 ferroptosis and increased cancer cell metastasis, Nature Communications (2021).

https://medicalxpress.com/news/2021-08-high-cholesterol-fuels-cance...

Is There Plastic in your Rain? Yes!

How the same plant species can program itself to flower at differen...

Researchers led by Professor Caroline Dean have uncovered the genetic basis for variations in the vernalization response shown by plants growing in very different climates, linking epigenetic mechanisms with evolutionary change.

The Probability of Another COVID-Level Pandemic Emerging is higher than you think

a new statistical study has discovered that large pandemics are much more common than you might expect. In fact, the team found that a pandemic with a similar level of impact to COVID-19 has around a 2 percent probability of occurring each year.

When you add that up across an entire lifetime, this means we each have a 38 percent chance of experiencing a big one at least once, and the odds look set to get worse with time.

The most important takeaway is that large pandemics like COVID-19 and the Spanish flu are relatively likely.

The team looked at the historical record of epidemics from the year 1600 until now. They found 476 documented epidemics, around half of which had a known number of casualties. About 145 caused less than 10,000 deaths, while 114 others we know existed, but not the number of deaths.

Importantly, infectious diseases that are currently active were excluded from the analysis – so that means no COVID-19, HIV, or malaria.

The team used detailed modelling with a generalized Pareto distribution to analyze the data, finding that the yearly number of epidemics is immensely variable, and an extreme epidemic like the Spanish flu of 1918-1920 had a probability of occurring somewhere between 0.3 and 1.9 percent each year over the last 400 years.

"The slow decay of probability with epidemic intensity implies that extreme epidemics are relatively likely, a property previously undetected due to short observational records and stationary analysis methods

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In the last 50 years, we've seen increasing levels of new pathogens spreading through humans. SARS-CoV-2 is the most obvious example, but even in the last few decades we've had swine flu, bird flu, Ebola, and many, many more.

"Together with recent estimates of increasing rates of disease emergence from animal reservoirs associated with environmental change," the team writes, "this finding suggests a high probability of observing pandemics similar to COVID-19 (probability of experiencing it in one's lifetime currently about 38 percent), which may double in coming decades.

So, even while we are recovering from a current outbreak, it's important that we don't assume we won't see another life-changing pandemic soon enough.

In fact, if we play our cards right, our response and resources for COVID-19 can prepare us for the next pandemic.

https://www.pnas.org/content/118/35/e2105482118

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Why the changing colour of our streetlights could be a danger for insect populations

Life on Earth has evolved alongside predictable cycles of day and night. But this pattern has become increasingly blurred. Between 2012 and 2016, satellite measurements revealed that the global area polluted by artificial light grew by 2% each year, intruding ever deeper into biodiversity hotspots like tropical forests.

In this context, there is an important change taking place in the world: the replacement of older, less energy-efficient sodium street-lighting with white LEDs.

LEDs used in streetlights typically emit white light, while sodium lamps have a characteristic yellow glow – as seen in the picture below. This change in the colour of artificial light is predicted to have major consequences for wildlife. That’s because white LEDs emit light across the entire visible spectrum. The more wavelengths emitted, the greater the diversity of species and biological processes that are likely to be disrupted.

Insects are known to be more sensitive to shorter, bluer wavelengths of light, which are largely absent from sodium lighting. Biological processes that are controlled by daylight and internal circadian rhythms, such as reproduction, are more likely to be disrupted or prevented by white LEDS.

A study results published in Science Advances recently were striking. Lighting reduced the numbers of caterpillars by between one half and one third. Lit areas almost universally had lower numbers than their darker counterparts. Sites with white LEDs also had a steeper reduction in numbers compared to sites with sodium lamps.

We suspect the reason there were fewer caterpillars in lit areas was because the lighting prevented females from laying eggs, a behaviour that has evolved in darkness. In addition, adult moths can be drawn up to streetlights, where they’re easy pickings for bats. Our recent review article revealed many other plausible mechanisms through which lighting could cause population declines throughout the moths’ life cycles.

https://advances.sciencemag.org/content/7/35/eabi8322

https://theconversation.com/why-the-changing-colour-of-our-streetli...

A Badge That Measures Exposures to Dangerous Chemicals

In a first, scientists capture a 'quantum tug' between neighboring water molecules

Water is the most abundant yet least understood liquid in nature. It exhibits many strange behaviors that scientists still struggle to explain. While most liquids get denser as they get colder, water is most dense at 39 degrees Fahrenheit, just above its freezing point. This is why ice floats to the top of a drinking glass and lakes freeze from the surface down, allowing marine life to survive cold winters. Water also has an unusually high surface tension, allowing insects to walk on its surface, and a large capacity to store heat, keeping ocean temperatures stable.

Now, a team of researchers   has made the first direct observation of how hydrogen atoms in water molecules tug and push neighboring water molecules when they are excited with laser light. Their results, published in Nature today, reveal effects that could underpin key aspects of the microscopic origin of water's strange properties and could lead to a better understanding of how water helps proteins function in living organisms.

Each water molecule contains one oxygen atom and two hydrogen atoms, and a web of hydrogen bonds between positively charged hydrogen atoms in one molecule and negatively charged oxygen atoms in neighboring molecules holds them all together. This intricate network is the driving force behind many of water's inexplicable properties, but until recently, researchers were unable to directly observe how a water molecule interacts with its neighbors.

The low mass of the hydrogen atoms accentuates their quantum wave-like behavior. This study is the first to directly demonstrate that the response of the hydrogen bond network to an impulse of energy depends critically on the quantum mechanical nature of how the hydrogen atoms are spaced out, which has long been suggested to be responsible for the unique attributes of water and its hydrogen bond network.

Direct observation of ultrafast hydrogen bond strengthening in liquid water, Nature (2021). DOI: 10.1038/s41586-021-03793-9 , www.nature.com/articles/s41586-021-03793-9

https://phys.org/news/2021-08-scientists-capture-quantum-neighborin...

YouTube says it removed 1mn 'dangerous' videos on COVID-19

YouTube said Wednesday it has removed more than one million videos with "dangerous coronavirus misinformation" since the start of the COVID-19 pandemic.

YouTube said in a blog post it relies on "expert consensus from health organizations," including the US Centers for Disease Control and the World Health Organization, but noted that, in some cases, "misinformation is less clear-cut" as new facts emerge.

YouTube said it was working to accelerate the process for removing videos with misinformation while simultaneously delivering those from authoritative sources.

IANS

Protecting gardens and crops from insects using the 'smell of fear'

For home gardeners and farmers, herbivorous insects present a major threat to their hard work and crop yields. The predator insects that feed on these bugs emit odors that pests can sense, which changes the pests' behavior and even their physiology to avoid being eaten. With bugs becoming more resistant to traditional pesticides, researchers now report they have developed a way to bottle the "smell of fear" produced by predators to repel and disrupt destructive insects naturally without the need for harsh substances.

Smell of fear: Harnessing predatory insect odor cues as a pest management tool for herbivorous insects, ACS Fall 2021.

New class of habitable exoplanets represent a big step forward in the search for life

A new class of exoplanet very different to our own, but which could support life, has been identified by astronomers, which could greatly accelerate the search for life outside our Solar System.

In the search for life elsewhere, astronomers have mostly looked for planets of a similar size, mass, temperature and atmospheric composition to Earth. However, astronomers  now think there are more promising possibilities out there.

The researchers have identified a new class of habitable planets, dubbed 'Hycean' planets—hot, ocean-covered planets with hydrogen-rich atmospheres—which are more numerous and observable than Earth-like planets.

The researchers say the results, reported in The Astrophysical Journal, could mean that finding biosignatures of life outside our Solar System within the next two or three years is a real possibility.

Many of the prime Hycean candidates identified by the researchers are bigger and hotter than Earth, but still have the characteristics to host large oceans that could support microbial life similar to that found in some of Earth's most extreme aquatic environments.

These planets also allow for a far wider habitable zone, or 'Goldilocks zone', compared to Earth-like planets. This means that they could still support life even though they lie outside the range where a planet similar to Earth would need to be in order to be habitable.

Habitability and Biosignatures of Hycean Worlds, Astrophysical Journal (2021). doi.org/10.3847/1538-4357/abfd9c

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 researchers to identify a new class of planets, Hycean planets, with massive planet-wide oceans beneath hydrogen-rich atmospheres. Hycean planets can be up to 2.6 times larger than Earth and have atmospheric temperatures up to nearly 200 degrees Celsius, but their oceanic conditions could be similar to those conducive for microbial life in Earth's oceans. Such planets also include tidally locked 'dark' Hycean worlds that may have habitable conditions only on their permanent night sides, and 'cold' Hycean worlds that receive little radiation from their stars.

Planets of this size dominate the known exoplanet population, although they have not been studied in nearly as much detail as super-Earths. Hycean worlds are likely quite common, meaning that the most promising places to look for life elsewhere in the Galaxy may have been hiding in plain sight.

However, size alone is not enough to confirm whether a planet is Hycean: other aspects such as mass, temperature and atmospheric properties are required for confirmation.

https://phys.org/news/2021-08-class-habitable-exoplanets-big-life.h...

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