Discovering the magic in superconductivity's 'magic angle'

Researchers have produced new evidence of how graphene, when twisted to a precise angle, can become a superconductor, moving electricity with no loss of energy.

They reported on their finding of the key role that quantum geometry plays in allowing this twisted graphene to become a superconductor. 

Graphene is a single layer of carbon atoms, the lead that is found in a pencil.

In 2018, scientists at the Massachusetts Institute of Technology discovered that, under the right conditions, graphene could become a superconductor if one piece of graphene were laid on top of another piece and the layers were twisted to a specific angle—1.08 degrees—creating twisted bilayer graphene.

Ever since, scientists have been studying this twisted bilayer graphene and trying to figure out how this 'magic angle' works. The conventional theory of superconductivity doesn't work in this situation. so scientists  did a series of experiments to understand the origins of why this material is a superconductor. 

In a conventional metal, high-speed electrons are responsible for conductivity.

But twisted bilayer graphene has a type of electronic structure known as a "flat band" in which the electrons move very slowly—in fact at a speed that approaches zero if the angle is exactly at the magic one.

Under the conventional theory of superconductivity, electrons moving this slowly should not be able to conduct electricity.

With great precision the research group was able to obtain a device so close to the magic angle that the electrons were nearly stopped by usual condensed matter physics standards. The sample nevertheless showed superconductivity.

It is a paradox: How can electrons which move so slowly conduct electricity at all, let alone superconduct? It is very remarkable.

In their experiments, the research team demonstrated the slow speeds of the electrons and gave more precise measurements of electron movement than had been previously available.

And they also found the first clues as to what makes this graphene material so special.

They couldn't use the speed of electrons to explain how the twisted bilayer graphene is working. Instead, they had to use quantum geometry.

As with everything quantum, quantum geometry is complex and not intuitive. But the results of this study have to do with the fact that an electron is not only a particle, but also a wave—and thus has wavefunctions.

The geometry of the quantum wavefunctions in flat bands, together with the interaction between electrons, leads to the flow of electrical current without dissipation in bilayer graphene.

Their  experimental measurements suggest quantum geometry is 90% of what makes this a superconductor.

 Chun Lau, Evidence for Dirac flat band superconductivity enabled by quantum geometry, Nature (2023). DOI: 10.1038/s41586-022-05576-2. www.nature.com/articles/s41586-022-05576-2

Study: The faster El Niño decays, the fewer typhoons occur the following summer

As the largest climate signal on the interannual time scale, El Niño has pronounced impacts on typhoon activity. Recently, a growing number of studies have been focusing on the climatic effects of the pace of El Niño decay and the remarkable role this plays in the genesis position and intensity variations of typhoons. However, the response of the frequency of typhoon occurrence to the pace of El Niño decay remains unclear.

In a paper recently published in Atmospheric and Oceanic Science Letters, scientists attempted to address this issue. They present new evidence for variation in the pace of El Niño decay having a significant influence on the typhoon frequency in the summer following the mature winter of El Niño.

Firstly they classified El Niño cases into two categories: fast decaying [FD] and slow decaying [SD]. Interestingly, the typhoon occurrence frequency decreased sharply in the following summer only for FD El Niño cases. In order to explore the possible reason for this observed typhoon response, tehy further compared the environmental factors for typhoon development and the related atmospheric circulation processes between the FD and SD El Niño years.

Compared with those for SD El Niño years, fewer typhoons occurred in the following summer for FD El Niño years, and the causal mechanism was a stronger anticyclonic anomaly over the western North Pacific forced by tropical Indo-Pacific sea surface temperature (SST) anomalies. Therefore, the pace of El Niño decay might serve as an important factor in the prediction of typhoon activity.

However, the question of how these distinct patterns of tropical SST anomalies establish under FD and SD El Niño conditions needs to be studied in future work from the perspective of ocean dynamics.

Qun Zhou et al, Influence of the pace of El Niño decay on tropical cyclone frequency over the western north pacific during decaying El Niño summers, Atmospheric and Oceanic Science Letters (2023). DOI: 10.1016/j.aosl.2023.100328

Scientists find first evidence that black holes are the source of dark energy

Observations of supermassive black holes at the centers of galaxies point to a likely source of dark energy—the 'missing' 70% of the universe.

The measurements from ancient and dormant galaxies show black holes growing more than expected, aligning with a phenomenon predicted in Einstein's theory of gravity. The result potentially means nothing new has to be added to our picture of the universe to account for dark energy: black holes combined with Einstein's gravity are the source.

The conclusion was reached by a team of 17 researchers in nine countries, led by the University of Hawai'i and including Imperial College London and STFC RAL Space physicists. The work is published in two papers in the journals The Astrophysical Journal and The Astrophysical Journal Letters.

If the theory holds, then this is going to revolutionize the whole of cosmology, because at last we've got a solution for the origin of dark energy that's been perplexing cosmologists and theoretical physicists for more than 20 years.

Duncan Farrah et al, A Preferential Growth Channel for Supermassive Black Holes in Elliptical Galaxies at z ≲ 2, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acac2e

The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acb704. iopscience.iop.org/article/10. … 847/2041-8213/acb704

The global toll of chicken and salmon

Farmed chicken and salmon are among the most sustainable meats available, but they still exert intense environmental pressures on the hotspots where farming.... The first study to map their impact on a global scale found that, by some metrics, chicken farming is more efficient than salmon farming: it yields 55 times more food per year because chickens grow to full size faster. But the study notes that marine wildlife disturbed by farming tend to recover, whereas habitats and species affected by farming on land generally don’t. And fishmeal that is used to make chicken feed is taken from the ocean, anyway.

https://www.cell.com/current-biology/fulltext/S0960-9822(23)00071-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982223000714%3Fshowall%3Dtrue

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Sleeping volcanoes leak more sulfur

Thanks to ‘passive degassing’ from dormant volcanoes, the atmosphere in pre-industrial times contained many more climate-cooling sulfur particles than we thought. Researchers examined Greenland ice cores to study the pristine Arctic atmosphere. They found that volcanoes are a major source of sulfur emissions, even during decades without major eruptions — in fact, dormant volcanoes belch out a lot more sulfur over those time spans than do active ones. Sulfate aerosols have a net cooling effect, but adding more gives diminishing returns. So, if natural levels are higher than we thought, we might have overest..., perhaps by as much as half.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL102061?ut...

Scientists discover mirror neurons in mice and find they're tuned to aggression

In nature, when two animals fight, they are seldom without an audience. 

Researchers wanted to know how the animals on the sidelines perceive these aggressive interactions. In a new study in mice, they discovered that some neurons in a part of the brain known as the "rage center" fire both when a mouse is fighting and when it watches others fight. Such neurons are known as mirror neurons—they are active when an animal is doing the behaviour and when it's watching another animal do that same behaviour.

The study is the first to find mirror neurons in mice and in the hypothalamus—an evolutionarily ancient part of the brain—hinting at a more primal origin for mirror neurons than previously thought.

Aggression in the wild is rarely a private affair. Aggression is usually not only to defeat the other animal, but also to tell others in the vicinity, 'Hey, I'm the boss.' It's a public display. Previous work  traced aggression in male mice to a cluster of brain cells in a part of the ventromedial hypothalamus. (In female mice, the same neurons do not trigger aggression.) Dubbed the "rage center," these neurons could activate aggression, but also seemed sensitive to a mouse's socialization—communally housed mice were less aggressive. 

What else are these neurons sensitive to? Researchers proposed that these neurons might be sensitive to aggression between other mice.

And that turned out to be the case: They're mirroring aggression by other animals. 

Using precise imaging techniques, the researchers recorded activity in the rage center of male mice engaged in a brawl and those witnessing a fight.

Sparking a fight between male mice is simple—the researchers had only to introduce a male mouse into another's cage. The resident mouse would attack the intruder and display threatening behavior, like tail-rattling. To set up a witness, the researchers allowed a lone mouse to observe these fights through a transparent divider.

They found that a nearly identical set of neurons in the rage center were active in both fighters and observers—qualifying them as mirror neurons.

Another surprise was that in an observer, aggression-mirroring neurons were triggered by sight, whereas in fighting mice, they are triggered by the smell of pheromones. Video recordings revealed that mirror neurons fired only in the moments when the observer was facing the fighters, not when it was turned away. And when the researchers turned off the lights, the observer's mirror neurons were entirely unresponsive to the fracas next door.

The researchers found also that these mirror neurons seemed innately tuned to aggression, even in mice that had never witnessed or engaged in aggressive behavior. They did not fire when mice watched other behaviors, like sniffing, grooming or running on a wheel.

Part 1

Next, in a series of experiments, the researchers demonstrated that the aggression-mirroring neurons not only sensed aggression but enabled it. When they selectively inhibited these neurons, mice were less irked by a male intruder—and initiated only a third as many attacks or tail-rattles as normal mice.

Inversely, when the mirror neurons were switched on, the mice became indiscriminately aggressive. Not only did they initiate three times more attacks on male intruders than usual, they attacked even female visitors, who normally would have prompted frisky coupling behavior. Needless to say, they were less successful in mating. The male mice were so riled up they even tail-rattled at their own mirror reflection.

It tells you that the activity of these neurons is sufficient for aggression, even when there's no provocation. 

The fact that aggression-mirroring neurons exist in such a primitive part of the brain indicates they may have been conserved across evolution, from mouse to human. It suggests that we might have the same neurons, and maybe they encode some qualities of aggression in ourselves. 

The researchers did not investigate how observing aggressive behavior affected the observers, but they offer their own speculation—perhaps, like boxers studying videos of their opponent's moves, the mice on the sidelines learn to be better fighters.

Taehong Yang et al, Hypothalamic neurons that mirror aggression, Cell (2023). DOI: 10.1016/j.cell.2023.01.022

Part 2

Novel method to accurately measure key marker of biological aging

Telomeres—the caps at the ends of chromosomes that protect our genetic materials from the brunt of cellular wear and tear—are known to shorten and fray over time. Lifestyle, diet and stress can exacerbate this process, leading to early loss of telomere protection and increasing the chances of early aging and diseases, such as cancer and heart disease.

To date, approaches for measuring biological aging based on telomere length have been limited as they can only ascertain average telomere lengths within a pool of DNA fragments, or they are time-consuming and require highly-skilled specialists. Being able to accurately and efficiently measure the length of an individual's telomeres could open the doors to developing lifestyle interventions that slow aging and prevent disease.

Scientists have recently devised a way to rapidly and precisely measure the length of a single telomere.

They applied a novel approach that uses DNA sequences—they call them 'telobaits'—to latch onto the ends of telomeres in large pools of DNA fragments, like fishing in pond. Then, with specific scissor-like enzymes, they snip the telomeres out of the pools.

Using high-throughput genetic sequencing technology, they were able to read the DNA 'letters' that comprised each individual telomere, allowing them to very precisely measure their lengths.

The team successfully validated this approach when they tested it using human cell lines and patient cells. Interestingly, the sequencing results revealed that the genetic sequences within certain parts of the telomeres, known as telomeric variant sequences, were distinct to each individual person.

The researchers think this new approach could be used as a predictive biomarker for human aging and disease at the individual level, as well as for population-level studies on the impacts of lifestyle, diet and the environment on human health.

Cheng-Yong Tham et al, High-throughput telomere length measurement at nucleotide resolution using the PacBio high fidelity sequencing platform, Nature Communications (2023). DOI: 10.1038/s41467-023-35823-7

Nanoparticles perform ultralong distance communication, have 'no counterpart or analogue in nature'

Chemists have designed a new photonic lattice with properties never before seen in nature. In solid materials, atoms must be equally spaced apart and close enough together to interact effectively. Now, new architectures based on stacked lattices of nanoparticles show interactions across unprecedentedly large distances.

When one lattice is stacked on top of the other, the nanoparticles can still interact with each other—even when the vertical separation among particles is 1,000 times the distance of the particle-to-particle spacing within the horizontal plane.

Because the nanoparticles can communicate across ultralong distances, the stacked architecture offers potential applications in remote sensing and detection.

This type of long-range coupling has not been observed before for any stacked periodic material. Other electronic or photonic stacked layers are separated vertically by a spacing similar to the horizontal periodicity of the building unit in the single layer. This is an entirely new class of engineered materials that have no counterpart or analogue in nature.

Jun Guan et al, Far-field coupling between moiré photonic lattices, Nature Nanotechnology (2023). DOI: 10.1038/s41565-023-01320-7

Researchers develop a novel 2D material that uses a virus to kill cancer cells

Electro-thermal therapy, which involves applying electrical signals to nanomaterials, provides high cancer cell targeting accuracy and is highly bio-compatible. In this research, scientists have designed a novel thermal-based therapy nano-system that destroys more than 20% of pancreatic cancer cells using microsecond electrical pulses and with excellent bio-compatibility.

Electro-thermal therapy works by injecting two dimensional (2D) materials in cancer cells and applying electrical currents to the cells. This causes the materials to heat up and kill neighboring cancer cells. Traditional electro-thermal therapy with 2D materials however, can fail as a result of weak cancer cell ablation. This is due to the limited amount of materials assembled on the cancer cells and the weak Joule heating generated in the material.

To alleviate these issues, the researchers deposited the M13 virus on molybdenum disulfide (MoS₂) layered materials to create a hybrid nanomaterial MoS₂ Nanostructure with M13 virus (the authors call it MNM). Moreover, they altered the nanomaterial surfaces with polyethylene glycol (PEG) to improve bio-compatibility.

The introduction of the M13 virus improves the electro-thermal therapy performance. Compared to conventional 2D materials, a larger amount of MNM assembles on the cancer cells due to the higher specificity of the binding of the M13 virus to cancer cells. Due to the high electrical conductivity of the MoS₂ material, a strong Joule heating is also generated.

As a result, a larger amount of heat is produced in the nanomaterials, and can be used to kill a larger population of the cancer cells. For example, the MNM nanosystem can decrease the percentage of cancer cells by 23%, which is approximately 2 times higher than what current thermal-based therapy nano-systems can do.

Maria P. Meivita et al, An Efficient, Short Stimulus PANC-1 Cancer Cell Ablation and Electrothermal Therapy Driven by Hydrophobic Interactions, Pharmaceutics (2022). DOI: 10.3390/pharmaceutics15010106

Climate lessons from the last global warming

The Earth experienced one of the largest and most rapid climate warming events in its history 56 million years ago: the Paleocene-Eocene Thermal Maximum (PETM), which has similarities to current and future warming. This episode saw global temperatures rise by 5°C–8°C. It was marked by an increase in the seasonality of rainfalls, which led to the movement of large quantities of clay into the ocean, making it uninhabitable for certain living species.

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Engineered wood grows stronger while trapping carbon dioxide

Rice University scientists have figured out a way to engineer wood to trap carbon dioxide through a potentially scalable, energy-efficient process that also makes the material stronger for use in construction.

Keeping drivers safe with a road that can melt snow, ice on its own

Slipping and sliding on snowy or icy roads is dangerous. Salt and sand help melt ice or provide traction, but excessive use is bad for the environment. And sometimes, a surprise storm can blow through before these materials can be applied. Now, researchers reporting in ACS Omega have filled microcapsules with a chloride-free salt mixture that's added into asphalt before roads are paved, providing long-term snow melting capabilities in a real-world test.

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Driving on snowy roads at or near-freezing temperatures can create unsafe conditions, forming nearly invisible, slick black ice, if roads aren't cleaned quickly enough. But the most common ways to keep roads clear have significant downsides:

• Regular plowing requires costly equipment, is labor intensive and can damage pavement.
• Heavy salt or sand applications can harm the environment.
• Heated pavement technologies are prohibitively expensive to use on long roadways.

Recently, researchers have incorporated salt-storage systems into "anti-icing asphalt" to remove snow and prevent black ice from forming. However, these asphalt pavements use corrosive chloride-based salts and only release snow-melting substances for a few years.

So now they now wanted to develop a longer-term, chloride-free additive to effectively melt and remove snow cover on winter roads.

The researchers prepared a sodium acetate salt and combined it with a surfactant, silicon dioxide, sodium bicarbonate and blast furnace slag—a waste product from power plant operations—to produce a fine powder. They then coated the particles in the powder with a polymer solution, forming tiny microcapsules. Next, the team replaced some of the mineral filler in an asphalt mixture with the microcapsules. In initial experiments, a pavement block made with the new additive lowered the freezing point of water to -6 F. And the researchers estimated that a 5-cm-thick layer of the anti-icing asphalt would be effective at melting snow for seven to eight years. A real-world pilot test of the anti-icing asphalt on the off-ramp of a highway showed that it melted snow that fell on the road, whereas traditional pavement required additional removal operations. Because the additive used waste products and could release salt for most of a road's lifetime, the researchers say that is a practical and economic solution for wintertime snow and ice removal.

 Yingfei Zhao et al, Preparation of a Green Sustained-Release Microcapsule-Type Anti-Icing Agent for Asphalt Pavement and Its Application Demonstration Project, ACS Omega (2023). DOI: 10.1021/acsomega.2c07212

Evolution: Mini-proteins in human organs appeared 'from nowhere'

Every biologist knows that small structures can sometimes have a big impact: Millions of signaling molecules, hormones, and other biomolecules are bustling around in our cells and tissues, playing a leading role in many of the key processes occurring in our bodies. Yet despite this knowledge, biologists and physicians long ignored a particular class of proteins—their assumption being that because the proteins were so small and only found in primates, they were insignificant and functionless.

However, the discoveries recently made changed this view. The existence of thousands of new microproteins in human organs has been established now.

Bioinformatic gene analyses revealed that most human microproteins developed millions of years later in the evolutionary process than the larger proteins currently known to scientists.

Yet the huge age gap doesn't appear to prevent the proteins from "talking" to each other. Lab experiments showed that the young and old proteins can bind to each other—and in doing so possibly influence each other.  The ability to bind does suggest the proteins might influence each other's functioning.

Unlike the known, old proteins that are encoded in our genome, most microproteins emerged more or less "out of nowhere—in other words, out of DNA regions that weren't previously tasked with producing proteins.

And because these small proteins only emerged during human evolution, they are missing from the cells of most other animals, such as mice, fish and birds. These animals, however, have been found to possess their own collection of young, small proteins.

During their work, the researchers also discovered the smallest human proteins identified to date. They found over 200 super-small proteins, all of which are smaller than 16 amino acids.

Scientists therefore suspect that contrary to long-held assumptions, the microproteins play a key role in a variety of cellular functions. The young proteins might also be heavily involved in evolutionary development thanks to comparatively rapid "innovations and adaptations."

It's possible that evolution is more dynamic than previously thought.

Norbert Hubner & colleauges, Evolutionary origins and interactomes of human young microproteins and small peptides translated from short open reading frames, Molecular Cell (2023). DOI: 10.1016/j.molcel.2023.01.023. www.cell.com/molecular-cell/fu … 1097-2765(23)00075-8

Blood stem cells shown to be susceptible to ferroptosis, a type of cell death

The body is constantly replenishing the blood with new red and white blood cells thanks to a small but important group of cells called hematopoietic stem cells (HSCs). Now, researchers have found that these cells are particularly vulnerable to ferroptosis, a kind of cell death triggered by iron.

Scientists have studied ferroptosis mostly in cancer cells, but this study, published recently in the journal Cell, is one of the first to show that a normal cell type is also susceptible to this form of cell death. The findings also point to potential side effects of drugs that are being developed to boost ferroptosis to kill cancer cells. And they suggest new strategies for treating blood disorders caused by low levels of HSCs.

The research team first discovered this ferroptosis vulnerability in a rare bone marrow disorder, but were surprised to find this feature in healthy HSCs as well. They also found that this susceptibility arises from the cells' decreased rate of protein production.

This is a good example where a rare disease can teach us much more about fundamental biological processes that we wouldn't have discovered otherwise.

Jiawei Zhao et al, Human hematopoietic stem cell vulnerability to ferroptosis, Cell (2023). DOI: 10.1016/j.cell.2023.01.020

Fun science: Physics

Here’s something that’s really amazing, but it also takes a bit of skill and patience too! How can you pick up a ball with a glass without touching the ball itself? Place the glass over the ball and then start spinning the glass around in a circular motion. Once the ball starts spinning inside the glass, lift it from the table. Watch out! If the ball isn’t spinning enough, then you won’t be able to lift it.

This is the explanation:

The Spinning Ball experiment Place the jar over the ball so that the ball is inside the mouth of the canning jar. Then start spinning the glass around in a circular motion Once the ball starts spinning inside the glass lift it from the table top. The ball is lifted from the table and will continue to spin inside the glass until it loses is speed. As a ball velocity increases inside the glass, the centripetal force increases. That force is what's keeping the ball stuck to the walls of the glass. As the ball goes faster, the resulting friction begins to cancel out the force of gravity acting on the ball. The centripetal force and friction, and those factors rely on velocity. If the ball goes too slowly, the velocity won't increase enough to out-do the force of gravity, and the ball will fall out of the glass.

Don’t Know CPR? There’s an App for That

Fibre discovery could shape better gut health

Changing the structure of a dietary fibre commonly used in a range of food products has been found to promote healthy gut bacteria and reduce gas formation, a finding that could help people with intolerances to fibre and irritable bowel conditions.

A team of scientists examined psyllium, a type of natural dietary fibre that is used in a range of products including cereals and yoghurts. They showed that the physical state of the fibre has a major impact on gas production which often is linked to bowel discomfort. The findings have been published in Food Hydrocolloids.

The team performed in vitro fermentation experiments seeded with human stool. They conducted analysis of fermentation products and evaluated the impact of different structures on the broad categories of microorganisms.

Although fibre is an important part of any diet, for many people it can cause bowel discomfort and for people with IBS or IBD fibre can be a trigger. This is because some foods cause bacterial interactions in the gut that create gas that can lead to pain or discomfort. This new study shows that the physical state of the fibre has a major impact on gas production by creating beneficial compounds that promote the creation of the good bacteria in the gut.

Psyllium fibre comes from the seeds of Plantago ovata plants, known by many common names such as blond plantain. These seeds produce a jelly-like material called mucilage, which comes in a variety of shapes and forms and these feature long-chain sugars, called polysaccharides. It is these polysaccharides that lead to the production of beneficial short-chain fatty acids that positively contribute to gut health and systemic metabolism. This study shows that different physical states of fibre impact the way dietary fibre breaks down and that microbes ‘colonise fibre’ during fermentation.

These findings show that there are new opportunities for designing targeted structures using psyllium, either through seed processing or selective breeding, to achieve new fibre materials with clear clinical benefit above that of unrefined psyllium powders aiding in the treatment of gastrointestinal discomfort.

Research is already underway to use this new knowledge to create and test psyllium-mimicking materials as medical nutrition which could provide a source of fibre for people with some bowel conditions and trials will be starting in the Spring.

Hannah C. Harris, Noelia Pereira, Todor Koev, Yaroslav Z. Khimyak, Gleb E. Yakubov, Frederick J. Warren. The impact of psyllium gelation behaviour on in vitro colonic fermentation properties. Food Hydrocolloids, 2023; 139: 108543 DOI: 10.1016/j.foodhyd.2023.108543

 Volcanoes Leak Climate-Changing Gasses Into The Atmosphere Even While Dormant

We know volcanoes can cause dramatic shifts in the atmosphere when they erupt, but what about those long stretches of time when they appear to have fallen silent? A new study suggests that dormant volcanoes could be leaking out much more sulfur than we thought.

In fact, we might have underestimated sulfur output from sleeping volcanoes by a factor of three. That could mean a recalibration of climate and air quality models, as sulfur is one of the most important elements in terms of providing a climate cooling effect.

These findings are based on tiny particles trapped in layers of an ice core extracted from central Greenland, showing the make-up of the atmosphere circulating above the Arctic between the years 1200 and 1850. Sulfur emissions from dormant volcanoes were much higher than expected.  On longer timescales the amount of sulfate aerosols released during passive degassing is much higher than during eruptions.

It was found that passive degassing releases at least 10 times more sulfur into the atmosphere, on decadal timescales, than eruptions, and it could be as much as 30 times more.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL102061

Smart insole to identify and mitigate workplace slips, trips and falls

Psyllium Husk is simple Sago Dana in India - used for centuries for Stomach cleaning - it's also universally used for providing a stomach lining which reduces alcohol potency! Any comments Dr. Krishna?

Pungent ginger compound puts immune cells on heightened alert

Ginger has a reputation for stimulating the immune system. New results from research now support this thesis. In laboratory tests, small amounts of a pungent ginger constituent put white blood cells on heightened alert. The study also shows that this process involves a type of receptor that plays a role in the perception of painful heat stimuli and the sensation of spiciness in food.

Whether as a medicinal plant or foodstuff, ginger is also becoming increasingly popular. However, even though ginger consumption has increased, the question arises as to whether normal consumption levels are sufficient to achieve health effects. And if so, which compounds and molecular mechanisms play a role in this.

To help clarify these questions, researchers conducted extensive research. 

As the study shows, significant amounts of pungent ginger compounds enter the blood about 30 to 60 minutes after consuming one liter of ginger tea. By far the highest levels were achieved by [6]-gingerol, with plasma concentrations of approximately 7 to 17 micrograms per liter.

The pungent compound is known to exert its "taste" effect via the so-called TRPV1 receptor, an ion channel located on the surface of nerve cells that responds to painful heat stimuli as well as to pungent compounds from chili and ginger. Since some studies suggest that white blood cells also possess this receptor, the research team tested whether [6]-gingerol influences the activity of these immune cells.

In a first step, the team succeeded in detecting the receptor on neutrophil granulocytes. These cells make up about two-thirds of white blood cells and serve to combat invading bacteria. Further laboratory experiments by the research group also showed that even a very low concentration of almost 15 micrograms of [6]-gingerol per liter is sufficient to put the cells on heightened alert.

Thus, compared to control cells, the stimulated cells reacted about 30 percent more strongly to a peptide that simulates a bacterial infection. Addition of a TRPV1 receptor-specific inhibitor reversed the effect induced by [6]-gingerol.

Thus, at least in experiments, very low [6]-gingerol concentrations are sufficient to affect the activity of immune cells via the TRPV1 receptor. In blood, these concentrations could theoretically be achieved by consuming about one liter of ginger tea.

These  results support the assumption that the intake of common amounts of ginger may be sufficient to modulate cellular responses of the immune system. Nevertheless, there are still many unanswered questions at the molecular, epidemiological and medical levels that need to be addressed with the help of modern food and health research.

Gaby Andersen et al, [6]‐Gingerol Facilitates CXCL8 Secretion and ROS Production in Primary Human Neutrophils by Targeting the TRPV1 Channel, Molecular Nutrition & Food Research (2022). DOI: 10.1002/mnfr.202200434

Changes in how the heart produces energy may be the earliest signal of cardiac deterioration

Heart failure is often identified only when the heart has already deteriorated. This is in large part because the cause is unknown for about 70% of people who experience heart failure.

Researchers now discovered that one of the earliest signs of heart failure is a change in how the heart  produces energy, with findings offering a potential way to preempt heart failure before the heart begins to deteriorate.

 The research may also help to explain the diversity of causes underlying heart failure.

Dysregulation of energy production is the earliest sign of heart failure. People associate deficiency in energy production with later stage heart failure, but these new findings show this could actually be the cause of heart failure, not a result.

In a healthy heart, a protein called lysine demethylase 8 (Kdm8) helps to maintain a balanced energy use, also known as metabolism, by repressing TBX15, another protein that decreases energy production.

In a study published recently in Nature Cardiovascular Research, the researchers  analyzed a large dataset on gene expression, the process by which DNA is converted to proteins, in human hearts at a later stage of heart failure and found that KDM8 was less active. This allowed TBX15 to be more highly expressed, leading to changes in metabolism. Researchers also found that TBX15 was expressed at the highest levels in hearts where energy production genes were most strongly suppressed. There are many genes that help regulate energy production in our bodies, but researchers were able to identify changes in specific proteins that occur well before cardiac deterioration.

After identifying change in energy production as an early sign of heart failure, the research team drilled down further to explore how metabolic pathways could be modified to prevent the failure. In doing so they found that the nicotinamide adenine dinucleotide (NAD+) pathway, which regulates energy metabolism, was less active. The team was then able to intervene and prevent heart failure in a mouse model by providing NAD+ injections and boosting energy production. This research suggests it may be possible to alter certain metabolic pathways to prevent heart failure before damage to the heart begins.

Abdalla Ahmed et al, KDM8 epigenetically controls cardiac metabolism to prevent initiation of dilated cardiomyopathy, Nature Cardiovascular Research (2023). DOI: 10.1038/s44161-023-00214-0

Evolution -correct depiction

This one shows the relationship with other modern apes and the other hominids.

Granted, it does not have the poster-like quality of the classical image, and it’s a lot more cluttered. But at least it is much more correct.

This old pic of evolution  is  misleading and incomplete. The problem with this old image is that first,  it suggests a linear progression. The second is that it suggests that we are descendants of chimpanzees. And the third is that early Homo sapiens were not white – it’s actually a pretty recent phenomenon, around 7,500–8,500 BCE in Europe.

A robot that can help firefighters during indoor emergencies

Robots could be valuable assistants for most first responders, as they could help them to remotely monitor or intervene in areas that are inaccessible or life-threatening for humans. Firefighters, who are at high risk of getting injured during their missions, would undoubtedly benefit from the assistance of reliable mobile robots.

Researchers recently created an autonomous ground robot that could assist firefighters when they are tackling emergencies in indoor environments. Their system, introduced in the Journal of Field Robotics, could allow agents responding to fire emergencies to plan their interventions better, clearing safe paths for them to access affected areas and supporting them during evacuations.

This work is part of a project called HelpResponder, which aims to reduce the accident rates and mission times of intervention teams This is achieved using fixed beacons, drones, and ground robots. This new robot can monitor its surrounding environment, sharing the data it collects with human agents. This is achieved using various sensors that can measure the temperature, humidity and air quality in an indoor setting, as well as its position and the position of other objects. This data is then saved in a database that can be remotely accessed by firefighters through a smartphone application. 

N. Fernández Talavera et al, An autonomous ground robot to support firefighters' interventions in indoor emergencies, Journal of Field Robotics (2023). DOI: 10.1002/rob.22150

M. Cristina Rodriguez-Sanchez et al, HelpResponder—System for the Security of First Responder Interventions, Sensors (2021). DOI: 10.3390/s21082614

Fernández Talavera, Sistema de navegación autónomo en entornos reales y simulados para situaciones de emergencia, BURJC Digital (2021). hdl.handle.net/10115/18048

Survey of fire victims in Spain. Fundacion MAPFRE(2021). www.fundacionmapfre.org/en/pub … -fire-in-spain-2014/

Juan Jesús Roldán-Gómez et al, A Survey on Robotic Technologies for Forest Firefighting: Applying Drone Swarms to Improve Firefighters' Efficiency and Safety, Applied Sciences (2021). DOI: 10.3390/app11010363

Weaponizing part of the SARS-CoV-2 spike protein against itself to prevent infection

The virus that causes COVID-19, called SARS-CoV-2, uses its spike protein in order to stick to and infect our cells. The final step for the virus to enter our cells is for part of its spike protein to act like a twist tie, forcing the host cell's outer membrane to fuse with the virus.

Now researchers have generated a molecule based on the twisted part of the spike protein (called HR2), which sticks itself onto the virus and prevents the spike protein from twisting. The reason the longHR2_42 inhibitor may work against an evolving virus is that it is based on part of the spike protein that hasn't changed even as other parts have.

Kailu Yang et al, Nanomolar inhibition of SARS-CoV-2 infection by an unmodified peptide targeting the prehairpin intermediate of the spike protein, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2210990119

Conference: www.biophysics.org/2023meeting#/

Experts discover how zebra stripes work to thwart horsefly attacks

According to this new discovery, stark black-white distinctions and small dark patches are particularly effective in thwarting horsefly attack. These characteristics specifically eliminate the outline of large monochrome dark patches that are attractive to horseflies at close distances.

 A team of researchers theorized that the thin back stripes serve to minimize the size of local features on a zebra that are appealing to the biting flies.

We knew that horseflies are averse to landing on striped objects—a number of studies have now shown this, but it is not clear which aspects of stripes they find aversive. Is it the thinness of the stripes? The contrast of black and white? The polarized signal that can be given off objects? So researchers  set out to explore these issues using different patterned cloths draped over horses and filmed incoming horseflies. 

The team found that tabanid horseflies are attracted to large dark objects in their environment but less to dark broken patterns. All-gray coats were associated with by far the most landings, followed by coats with large black triangles placed in different positions, then small checkerboard patterns in no particular order. In another experiment, they found contrasting stripes attracted few flies whereas more homogeneous stripes were more attractive.

This suggests that any hoofed animal that reduces its overall dark outline against the sky will benefit in terms of reduced ectoparasite attack.

Tim Caro et al, Why don't horseflies land on zebras?, Journal of Experimental Biology (2023). DOI: 10.1242/jeb.244778

Scientists make stunning discovery, find new protein activity in telomeres

Once thought incapable of encoding proteins due to their simple monotonous repetitions of DNA, tiny telomeres at the tips of our chromosomes seem to hold a potent biological function that's potentially relevant to our understanding of cancer and aging.

Reporting in the Proceedings of the National Academy of Sciences

researchers made the stunning discovery that telomeres contain genetic information to produce two small proteins, one of which they found is elevated in some human cancer cells, as well as cells from patients suffering from telomere-related defects.

Based on this research, they think simple blood tests for these proteins could provide a valuable screen for certain cancers and other human diseases. These tests also could provide a measure of 'telomere health,' because we know telomeres shorten with age.

Telomeres contain a unique DNA sequence consisting of endless repeats of TTAGGG bases that somehow inhibit chromosomes from sticking to each other. Two decades ago, researchers showed that the end of a telomere's DNA loops back on itself to form a tiny circle, thus hiding the end and blocking chromosome-to-chromosome fusions. When cells divide, telomeres shorten, eventually becoming so short that the cell can no longer divide properly, leading to cell death.

Scientist first identified telomeres about 80 years ago, and because of their monotonous sequence, the established dogma in the field held that telomeres could not encode for any proteins, let alone ones with potent biological function.

Researchers now conducted experiments—as described in the PNAS paper—to show how telomeric DNA can instruct the cell to produce signaling proteins they termed VR (valine-arginine) and GL (glycine-leucine). Signaling proteins are essentially chemicals that trigger a chain reaction of other proteins inside cells that then lead to a biological function important for health or disease.

They then chemically synthesized VR and GL to examine their properties using powerful electron and confocal microscopes along with state-of-the-art biological methods, revealing that the VR protein is present in elevated amounts in some human cancer cells, as well as cells from patients suffering from diseases resulting from defective telomeres.

It is it's possible that as we age, the amount of VR and GL in our blood will steadily rise, potentially providing a new biomarker for biological age as contrasted to chronological age. Scientists think inflammation may also trigger the production of these proteins.

 Al-Turki, Taghreed M. et al, Mammalian telomeric RNA (TERRA) can be translated to produce valine–arginine and glycine–leucine dipeptide repeat proteins, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2221529120

Indian women face fieldwork challenges

Female researchers face challenges participating in fieldwork in India — from trained local residents refusing to work with women to objections from family members over travel, prejudices surrounding the type of work considered appropriate for women, and a lack of role models. Although the extent of the effect is hard to measure, women in the country are under-represented in fields that require extensive fieldwork such as geology, evolutionary biology and environmental studies. “Changing that image of what a scientist and a field researcher should look like, should be the first step. Let’s start there,” says evolutionary biologist Ashwini Mohan.

https://www.rukhmabai.com/despite-progress-fieldwork-remains-a-stum...

Physicists create new model of ringing black holes

When two black holes collide into each other to form a new bigger black hole, they violently roil spacetime around them, sending ripples, called gravitational waves, outward in all directions. Previous studies of black hole collisions modeled the behavior of the gravitational waves using what is known as linear math, which means that the gravitational waves rippling outward did not influence, or interact, with each other. Now, a new analysis has modeled the same collisions in more detail and revealed so-called nonlinear effects.

Nonlinear effects are what happens when waves on the beach crest and crash. The waves interact and influence each other rather than ride along by themselves. With something as violent as a black hole merger, researchers expected these effects but had not seen them in their models until now. New methods for extracting the waveforms from their simulations have made it possible to see the nonlinearities.

In the future, the new model can be used to learn more about the actual black hole collisions that have been routinely observed by LIGO (Laser Interferometer Gravitational-wave Observatory) ever since it made history in 2015 with the first direct detection of gravitational waves from space. LIGO will turn back on later this year after getting a set of upgrades that will make the detectors even more sensitive to gravitational waves. Supercomputers are needed to carry out an accurate calculation of the entire signal: the inspiral of the two orbiting black holes, their merger, and the settling down to a single quiescent remnant black hole.

Keefe Mitman et al, Nonlinearities in black hole ringdowns, Physical Review Letters (2023). Accepted for publication: journals.aps.org/prl/accepted/ … 5c5aaa672c0e199adcff. On Arxiv: DOI: 10.48550/arxiv.2208.07380

Cellular senescence plays a significant role in cerebral tumours

Glioblastomas are the most common malignant tumors of the adult brain. They resist conventional treatment, including surgery, followed by radiation therapy and chemotherapy. Despite this armamentarium, glioblastomas inexorably recur.

In a new study published in Nature Communications, researchers have shown that the elimination of senescent cells, i.e., cells that have stopped dividing, can modify the tumor ecosystem and slow its progression. These results open up new avenues for treatment.

Glioblastoma, the most common adult brain cancer, affects 2 to 5 in 100,000 individuals. While the incidence of the disease is highest in those between 55 and 85 years old, it is increasing in all age groups. This effect can't be attributed to improved diagnostic techniques alone, suggesting the influence of environmental factors hitherto unidentified.

People with the disease have a median survival of 15 months after diagnosis, as the tumor infiltrates the brain very quickly. There is an urgent need to better understand the biology of the tumor, including the diversity of cell types of which it is composed, and their role. The challenge is to find new therapeutic targets and significantly increase the lifespan of patients.

Finding the weak spot of glioblastoma is no easy task. One recent approach consists in targeting a key biological process: cellular senescence. Initially identified during the normal aging of cells, it corresponds to the loss of their ability to divide. Interruption of the cell cycle has an advantage: it prevents the uncontrolled division of malignant cells. In that case, senescence contributes to the body's anti-tumor response.

Long considered a simple marker of aging, we now know that senescence occurs throughout life, especially in response to genotoxic stress—that is, an event that disrupts or damages DNA, such as chemotherapy

When cells enter senescence, they secrete various molecules. This is called the senescence-associated secretory phenotype—or secretome. The secretome can influence the cellular environment in a beneficial or detrimental way. For example, it can activate the immune system or, conversely, induce the formation of blood vessels that contribute to the irrigation of the cancerous tissue. It all depends on the molecules secreted.

Part 1

Although the effects of senescence may seem paradoxical at first sight, recent studies show that it is all a question of temporality... and context. "In the short term, the secretome is involved in recruiting immune cells to eliminate tumor cells. But in the long term, the accumulation of senescent cells can promote the destruction of the extracellular matrix—which allows the organization of cells into tissue—and the proliferation of malignant cells." The researchers wondered whether there was senescence in glioblastoma and, if so, what role it might play in the cancer progression. To do this, they investigated both an animal model of glioblastoma and tumor tissue removed from patients during surgery. The team first examined 28 patient tumors. They found, in varying proportions (0.4% to 7% of the original mass of glioblastoma), senescent cells of different cell types—tumoral, immune, or glial—located mainly in areas of malignant cell proliferation, as well as in necrosis zones. In mice, suppressing a part of the senescent tumor cells made it possible to modify the immune activity within the tumor and extend the animal's lifespan. The researchers then defined a characteristic signature of senescence based on the expression of 31 genes in mice and ensured that it was identical in humans. Researchers observed that the strong expression of this signature was associated with a poor prognosis. This shows the pro-tumor action of senescence in glioblastoma. Modulating cellular senescence could therefore constitute a new therapeutic avenue to be combined with conventional treatments—to increase their effectiveness.

Rana Salam et al, Cellular senescence in malignant cells promotes tumor progression in mouse and patient Glioblastoma, Nature Communications (2023). DOI: 10.1038/s41467-023-36124-9

Part 2

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Discovery of massive early galaxies defies prior understanding of the universe

Six massive galaxies discovered in the early universe are upending what scientists previously understood about the origins of galaxies in the universe.

These objects are way more massive than anyone expected. Researchers expected only to find tiny, young, baby galaxies at this point in time, but they've discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.

Using the first dataset released from NASA's James Webb Space Telescope, the international team of scientists discovered objects as mature as the Milky Way when the universe was only 3% of its current age, about 500-700 million years after the Big Bang. The telescope is equipped with infrared-sensing instruments capable of detecting light that was emitted by the most ancient stars and galaxies. Essentially, the telescope allows scientists to see back in time roughly 13.5 billion years, near the beginning of the universe as we know it.

But scientists think this is their first glimpse back this far, so it's important that they keep an open mind about what they are seeing. While the data indicates they are likely galaxies, they think there is a real possibility that a few of these objects turn out to be obscured supermassive black holes. Regardless, the amount of mass they discovered means that the known mass in stars at this period of our universe is up to 100 times greater than they had previously thought. Even if they cut the sample in half, this is still an astounding change.

In a paper published recently (Feb. 22) in Nature, the researchers show evidence that the six galaxies are far more massive than anyone expected and call into question what scientists previously understood about galaxy formation at the very beginning of the universe.

The revelation that massive galaxy formation began extremely early in the history of the universe upends what many of us had thought was settled science. Scientists have been informally calling these objects 'universe breakers'—and they have been living up to their name so far.

 Accounting for such a high amount of mass would require either altering the models for cosmology or revising the scientific understanding of galaxy formation in the early universe—that galaxies started as small clouds of stars and dust that gradually grew larger over time. Either scenario requires a fundamental shift in our understanding of how the universe came to be.

One way to confirm the team's finding and alleviate any remaining concerns would be to take a spectrum image of the massive galaxies. That would provide the team data on the true distances, and also the gasses and other elements that made up the galaxies. The team could then use the data to model a clearer of picture of what the galaxies looked like, and how massive they truly were. A spectrum will immediately tell us whether or not these things are real. 

 Ivo Labbe, A population of red candidate massive galaxies ~600 Myr after the Big Bang, Nature (2023). DOI: 10.1038/s41586-023-05786-2. www.nature.com/articles/s41586-023-05786-2

Study finds 'forever chemicals' disrupt key biological processes

A team of researchers  found that exposure to a mixture of synthetic chemicals found widely in the environment alters several critical biological processes, including the metabolism of fats and amino acids, in both children and young adults. The disruption of these biological processes is connected to an increased risk of a very broad range of diseases, including developmental disorders, cardiovascular disease, metabolic disease and many types of cancer.

Known as per- and polyfluoroalkyl substances, or PFAS, these man-made chemicals are used in a wide range of consumer and industrial products. PFAS are sometimes called "forever chemicals" because they break down very slowly and accumulate in the environment and human tissue.

Although individual PFAS are known to increase the risk of several types of disease, this study, published February 22 in Environmental Health Perspectives, is the first to evaluate which biological processes are altered by exposure to a combination of multiple PFAS, which is important because most people carry a mixture of the chemicals in their blood.

In this new study, it was found that exposure to a combination of PFAS not only disrupted lipid and amino acid metabolism but also altered thyroid hormone function.

Another important finding was the fact that exposure to a mixture of PFAS, rather than a single chemical of this type, drove the disruption of these biological processes. This finding was consistent across the two cohorts, even though they had different levels of PFAS exposure.

Metabolic signatures of youth exposure to mixtures of per- and polyfluoroalkyl 2 substances: A multi-cohort study, Environmental Health Perspectives (2023). DOI: 10.1289/EHP11372

Study shows certain wearable gadgets could interfere with implantable cardiac electronic devices

In this high-tech era, wearable devices such as smartwatches have proven to be invaluable companions for the health conscious. But a new study shows that for a small group of people, some of these electronic fitness gadgets could possibly be risky to their health—even potentially deadly.

This new study  shows that wearable devices such as the Samsung Galaxy watch 4, Fitbit smart scales, or Moodmetric smart rings, among others, have sensing technology that could interfere with cardiac implantable electronic devices (CIEDs) such as pacemakers, implantable cardioverter defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices.

This study raises a red flag. Researchers  have done this work in simulations and benchtop testing following Food and Drug Administration accepted guidelines, and these gadgets interfere with the correct functioning of the CIEDs they tested. These results call for future clinical studies evaluating the translation of their findings to patients wearing CIEDs and using these wearable devices.

Part 1

Certain fitness and wellness trackers could pose serious risks for people with cardiac implantable electronic devices (CIEDs) such as pacemakers, implantable cardioverter defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. Credit: Heart Rhythm

But after conducting comprehensive testing of bioimpedance on three cardiac CRT devices from manufacturers Medtronic, Boston Scientific, and Abbott, Sanchez Terrones' team learned the slight electrical currents from these wearable gadgets can interfere and sometimes confuse cardiac implantable devices into operating incorrectly.

In the case of a pacemaker, which sends small electrical impulses to the heart when it is beating too slowly, the bioimpedance's tiny electrical current could trick the heart into thinking it is beating fast enough, preventing the pacemaker from doing its job when it is supposed to.

Safety evaluation of smart scales, smart watches, and smart rings with bioimpedance technology shows evidence of potential interference in cardiac implantable electronic devices, Heart Rhythm (2023). DOI: 10.1016/j.hrthm.2022.11.026

Part 2

Anti-dust tech paves way for self-cleaning surfaces

Dust is a common fact of life, and it's more than just a daily nuisance—it can get into machinery and equipment, causing loss of efficiency or breakdowns.

Researchers  developed a new method to keep dust from sticking to surfaces. The result is the ability to make many types of materials dust resistant, from spacecraft to solar panels to household windows. They demonstrated  a surface that can clean itself. Particulates aren't able to stick to the surface, so they come off using just the force of gravity.

In tests, the researchers piled lunar dust on top of their engineered surfaces and then turned each surface on its side. The result: Only about 2% of the surface remained dusty, compared with more than 35% of a similarly smooth surface.

The researchers said the discovery boils down to things the human eye can't detect. In the experiments, the team altered the geometry of flat surfaces to create a tightly packed nanoscale network of pyramid-shaped structures. These sharp, angular structures make it difficult for the dust particles to stick to the material, instead sticking to one another and rolling off the material via gravity.

These structures provide a passive solution, meaning they don't require any extra energy or materials to remove dust. Compare that with more active solutions such as a car windshield that requires the use of windshield wipers and wiper fluid to clean off dust.

Samuel S. Lee et al, Engineering large-area anti-dust surfaces by harnessing interparticle forces, ACS Applied Materials & Interfaces (2023). DOI: 10.1021/acsami.2c19211. pubs.acs.org/doi/10.1021/acsami.2c19211

Spinal cord stimulation shown to instantly improve arm mobility after stroke

Neurotechnology that stimulates the spinal cord instantly improves arm and hand mobility, enabling people affected by moderate to severe stroke to conduct their normal daily activities more easily, report researchers.

A pair of thin metal electrodes resembling strands of spaghetti implanted along the neck engage intact neural circuits, allowing stroke patients to fully open and close their fist, lift their arm above their head or use a fork and knife to cut a piece of steak for the first time in years.

They discovered that electrical stimulation of specific spinal cord regions enables patients to move their arm in ways that they are not able to do without the stimulation. Perhaps even more interesting, they found that after a few weeks of use, some of these improvements endure when the stimulation is switched off, indicating exciting avenues for the future of stroke therapies.

Spinal cord stimulation technology uses a set of electrodes placed on the surface of the spinal cord to deliver pulses of electricity that activate nerve cells inside the spinal cord. This technology is already being used to treat high-grade, persistent pain. Additionally, multiple research groups around the world have shown that spinal cord stimulation can be used to restore movement to the legs after spinal cord injury.

But the unique dexterity of the human hand, combined with the wide range of motion of the arm at the shoulder and the complexity of the neural signals controlling the arm and hand, add a significantly higher set of challenges.

Following years of extensive preclinical studies involving computer modeling and animal testing in macaque monkeys with partial arm paralysis, researchers were cleared to test this optimized therapy in humans.

The sensory nerves from the arm and hand send signals to motor neurons in the spinal cord that control the muscles of the limb.

By stimulating these sensory nerves, one can amplify the activity of muscles that have been weakened by stroke. Importantly, the patient retains full control of their movements: The stimulation is assistive and strengthens muscle activation only when patients are trying to move.

In a series of tests adapted to individual patients, stimulation enabled participants to perform tasks of different complexity, from moving a hollow metal cylinder to grasping common household objects, such as a can of soup, and opening a lock. Clinical assessments showed that stimulation targeting cervical nerve roots immediately improves strength, range of movement and function of the arm and hand.

Unexpectedly, the effects of stimulation seem to be longer-lasting than scientists originally thought and persisted even after the device was removed, suggesting it could be used both as an assistive and a restorative method for upper limb recovery. Indeed, the immediate effects of the stimulation enable administration of intense physical training that, in turn, could lead to even stronger long-term improvements in the absence of the stimulation.

Moving forward, researchers continue to enroll additional trial participants to understand which stroke patients can benefit most from this therapy and how to optimize stimulation protocols for different severity levels.

Marco Capogrosso, Epidural stimulation of the cervical spinal cord for post-stroke upper-limb paresis, Nature Medicine (2023). DOI: 10.1038/s41591-022-02202-6. www.nature.com/articles/s41591-022-02202-6

Human height remained unchanged for 2,000 years in Milan, finds study

A study covering 2,000 years of male and female adult statures in Milan, Italy, has been published in the journal Scientific Reports, illustrating a stable environmental influence on height.

Human height depends on an interplay between genetics and environmental factors like fetal health, childhood nutrition, disease exposures, as well as environmental epigenetic factors that can reach back generations. While genetics alone may determine how tall a person could become, the environment they are born into plays a significant role in how much of that genetic growth potential is realized. Typically when we look around the world, we see that as health and nutrition have become more reliable since the industrial revolution, humans have reached increasingly greater heights.

In past studies, population stature has been linked to environmental factors. Human height dramatically reduced during the switch from hunter-gatherers to more agricultural societies. Human height has been slowly increasing since then, occasionally being shown to wax and wane with times of sustained prosperity, wars, famines, climate change, and exposure to plague.

In the study, researchers analysed 549 skeletal remains from 13 different sites, all within Milan. The remains all came from necropolises dedicated to the less wealthy classes of Milanese society. They were assigned to one of five historical periods: Roman Era (first–fifth centuries AD), Early Middle Ages (sixth–tenth centuries AD), Late Middle Ages (eleventh–fifteenth centuries AD), Modern Era (sixteenth–eighteenth centuries AD) and Contemporary Era (nineteenth–twentieth centuries AD).

About 100 individuals were assessed for each era, split between male and female. Stature was estimated, mostly using femur bones, according to a well-established forensic regression formula. Individual female heights ranged from 143.5 to 177.6 cm, with a mean of 157.8 cm (about 5'2''). Males ranged from 152.0 to 195.4 cm, with a mean of 168.5 cm (5'6''). There was no significant change in average heights when comparing the historical periods.

By focusing their study on a single geographic location with similar urban and socioeconomic characteristics, researchers were able to remove biases that might arise in studies of multiple populations with distinct environmental influences. With such a homogenous environment, external forces on population height, like wars, plagues, or climate, should have been obvious. Surprisingly, there were no significant fluctuations seen in the statures. Suggesting to the study authors that city life in Milan has provided a stable environment for thousands of years, even for its lowest-income inhabitants.

 Lucie Biehler-Gomez et al, The diachronic trend of female and male stature in Milan over 2000 years, Scientific Reports (2023). DOI: 10.1038/s41598-023-28406-5

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Scientists unlock key to drought-resistant wheat plants with longer roots

Growing wheat in drought conditions may be easier in the future, thanks to new genetic research.

An international team of scientists found that the right number of copies of a specific group of genes can stimulate longer root growth, enabling wheat plants to pull water from deeper supplies. The resulting plants have more biomass and produce higher grain yield, according to a paper published in the journal Nature Communications.

The research provides novel tools to modify wheat root architecture to withstand low water conditions.

Roots play a very important role in plants. The root absorbs the water and the nutrients to support plants' growth. This finding is a useful tool to engineer root systems to improve yield under drought conditions in wheat. 

Much has been done to improve wheat production but losses from water stress can erase other improvements. Plants that can adapt to low water conditions but have increased yield will be key to growing enough food for a growing population in the face of global warming.

Until now, little has been known about the genes that affect the root structure of wheat. The discovery of the gene family—known as OPRIII—and that different copies of these genes affect root length is a significant step.

The duplication of the OPRIII genes results in increased production of a plant hormone called Jasmonic acid that causes, among other processes, the accelerated production of lateral roots. Different dosages of these genes can be used to obtain different roots.

To get longer roots, the team of researchers used CRISPR gene editing technology to eliminate some of the OPRIII genes that were duplicated in wheat lines with shorter roots. By contrast, increasing the copies of these genes caused shorter and more branched roots. But inserting a rye chromosome, which result in decreased OPRIII wheat genes, caused longer roots.

Fine-tuning the dosage of the OPRIII genes can allow us to engineer root systems that are adapted to drought, to normal conditions, to different scenarios.

Knowing the right combination of genes means researchers can search for wheat varieties that have those natural variations and breed for release to growers planting in low-water environments.

Gilad Gabay et al, Dosage differences in 12-OXOPHYTODIENOATE REDUCTASE genes modulate wheat root growth, Nature Communications (2023). DOI: 10.1038/s41467-023-36248-y

Head injuries could be a risk factor for developing brain cancer

Cancer Researchers have provided important molecular understanding of how injury may contribute to the development of a relatively rare but often aggressive form of brain tumor called a glioma.

Previous studies have suggested a possible link between head injury and increased rates of brain tumors, but the evidence is inconclusive. The present work now identified a possible mechanism to explain this link, implicating genetic mutations acting in concert with brain tissue inflammation to change the behaviour of cells, making them more likely to become cancerous. Although this study was largely carried out in mice, it suggests that it would be important to explore the relevance of these findings to human gliomas.

Gliomas are brain tumors that often arise in neural stem cells. More mature types of brain cells, such as astrocytes, have been considered less likely to give rise to tumors. However, recent findings have demonstrated that after injury astrocytes can exhibit stem cell behavior again.

Researchers  therefore set out to investigate whether this property may make astrocytes able to form a tumour following brain trauma using a pre-clinical mouse model.

Part 1

Young adult mice with brain injury were injected with a substance which permanently labeled astrocytes in red and knocked out the function of a gene called p53—known to have a vital role in suppressing many different cancers. A control group was treated the same way, but the p53 gene was left intact. A second group of mice was subjected to p53 inactivation in the absence of injury.

Normally astrocytes are highly branched—they take their name from stars—but what we found was that without p53 and only after an injury the astrocytes had retracted their branches and become more rounded. They weren't quite stem cell-like, but something had changed. So scientists let the mice age, then looked at the cells again and saw that they had completely reverted to a stem-like state with markers of early glioma cells that could divide.

This suggested that mutations in certain genes synergized with brain inflammation, which is induced by acute injury and then increases over time during the natural process of aging to make astrocytes more likely to initiate a cancer. Indeed, this process of change to stem-cell like behavior accelerated when they injected mice with a solution known to cause inflammation.

The team then looked for evidence to support their hypothesis in human populations. They consulted electronic medical records of more than 20,000 people who had been diagnosed with head injuries, comparing the rate of brain cancer with a control group, matched for age, sex and socioeconomic status.

They found that patients who experienced a head injury were nearly four times more likely to develop a brain cancer later in life, than those who had no head injury. It is important to keep in mind that the risk of developing a brain cancer is overall low, estimated at less than 1% over a lifetime, so even after an injury the risk remains modest.

We know that normal tissues carry many mutations which seem to just sit there and not have any major effects. These new  findings suggest that if on top of those mutations, an injury occurs, it creates a synergistic effect.

In a young brain, basal inflammation is low so the mutations seem to be kept in check even after a serious brain injury. However, upon aging, the mouse work suggests that inflammation increases throughout the brain but more intensely at the site of the earlier injury. This may reach a certain threshold after which the mutation now begins to manifest itself.

Simona Parrinello, Injury primes mutation bearing astrocytes for dedifferentiation in later life, Current Biology (2023). DOI: 10.1016/j.cub.2023.02.013. www.cell.com/current-biology/f … 0960-9822(23)00152-5

Part 2

How birds got their wings

Modern birds capable of flight all have a specialized wing structure called the propatagium without which they could not fly. The evolutionary origin of this structure has remained a mystery, but new research suggests it evolved in nonavian dinosaurs. The finding comes from statistical analyses of arm joints preserved in fossils and helps fill some gaps in knowledge about the origin of bird flight.

How scientists hauling logs on their heads may have solved a Chaco Canyon mystery!

Why did researchers carry a log weighing more than 130 pounds for 15 miles? Their feat of endurance could reveal new information about how ancient peoples hauled more than 200,000 heavy timbers to a site in the modern-day Southwest called Chaco Canyon.

In a new study, several researchers reenacted a small part of a trek that people in the Southwest United States may have made more than 1,000 years ago.

They described their experiment Feb. 22 in the Journal of Archaeological Science: Reports.

This is also done by sherpas in Nepal.

The researchers  they were hoping to solve an archaeological mystery that has perplexed researchers for decades: How did ancient peoples transport more than 200,000 heavy construction timbers over 60 miles to a famous site in the Southwest called Chaco Canyon?

The team's findings show that the key to this testament to human labor may have been simple devices called tumplines. These straps, which sherpas, or native mountain peoples of Nepal, still widely use today, loop over the top of the head. They help porters to support weight using the bones of their neck and spine rather than their muscles. Archaeological evidence suggests that ancient peoples in the Southwest employed tumplines woven from yucca plants to transport everyday items like food and water.

Tumplines allow one to carry heavier weights over larger distances without getting fatigued.

Chaco Canyon sits near the border between New Mexico and Colorado. Thousands of people, the ancestors of today's Diné, or Navajo, and Pueblo peoples, may have lived there from around A.D. 850 to 1200. They built "Great Houses," which were as much as four stories tall and contained hundreds of rooms.

But how this society got its construction supplies has been a long-standing mystery. Human porters would have needed to carry 16-foot-long wooden beams to Chaco Canyon by foot—following a network of ancient roads to sites like the Chuska Mountains to the west.

The team's findings open up a new understanding of the day-to-day lives of the people who shaped the Southwest more than a thousand years ago.

the team's results show that supplying Chaco Canyon with goods may not have been as back-breaking an undertaking as archaeologists once assumed.

As these guys showed, you don't have to be super trained to carry a log.

ames A. Wilson et al, Were timbers transported to Chaco using tumplines? A feasibility study, Journal of Archaeological Science: Reports (2023). DOI: 10.1016/j.jasrep.2023.103876

Combining forces to advance ocean science

All Living Cells Could Have The Molecular Machinery For a 'Sixth Sense'

Every animal on Earth may house the molecular machinery to sense magnetic fields, even those organisms that don't navigate or migrate using this mysterious 'sixth sense'.

Scientists working on fruit flies have now identified a ubiquitous molecule in all living cells that can respond to magnetic sensitivity if it is present in high enough amounts or if other molecules assist it.

The new findings suggest that magnetoreception could be much more common in the animal kingdom than we ever knew. If researchers are right, it might be an astonishingly ancient trait shared by virtually all living things, albeit with differing strengths.

That doesn't mean all animals or plants can actively sense and follow magnetic fields, but it does suggest that all living cells might, including ours.

How we sense the external world, from vision, hearing through to touch, taste, and smell, are well understood.

But by contrast, which animals can sense and how they respond to a magnetic field remains unknown. This study has made significant advances in understanding how animals sense and respond to external magnetic fields - a very active and disputed field.

Magnetoreception might sound like magic to us, but plenty of fish, amphibians, reptiles, birds, and other mammals in the wild can sense the tug of Earth's magnetic field and use it to navigate space.

Because this force is essentially invisible to our species, it took a remarkably long time for scientists to notice it.

Only in the 1960s did scientists show that bacteria can sense magnetic fields and orient themselves in relation to those fields; in the 1970s, we found that some birds and fish follow Earth's magnetic field when migrating.

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Even to this day, however, it's still unclear how so many animals achieve these incredible feats of navigation.

In the 1970s, scientists suggested that this magnetic-compass sense could involve radical pairs, molecules with unpaired outer shell electrons that form a pair of entangled electrons whose spins are altered by the Earth's magnetic field.

Twenty-two years later, that study's lead author co-authored a new paper proposing a specific molecule in which the radical pairs could be formed.

This molecule – a receptor in the retina of migrating birds called a cryptochrome – can sense light and magnetism, and it seems to work through quantum entanglement.

In basic terms, when a cryptochrome absorbs light, the energy triggers one of its electrons, pushing it to occupy one of two spinning states, each of which is differently influenced by Earth's geomagnetic field.

Cryptochromes have been a leading explanation for how animals sense magnetic fields for two decades, but now researchers at the Universities of Manchester and Leicester have identified another candidate.

Manipulating the genes of fruit flies, the team found that a molecule called Flavin Adenine Dinucleotide (FAD), which usually forms a radical pair with cryptochromes, is actually a magnetoreceptor in and of itself.

This basic molecule is found at differing levels in all cells, and the higher the concentration, the more likely it is to impart magnetic sensitivity, even when cryptochromes are lacking.

In fruit flies, for instance, when FAD is stimulated by light, it generates a radical pair of electrons that are responsive to magnetic fields.

However, when cryptochromes are present alongside FADs, a cell's sensitivity to magnetic fields increases. The findings suggest that cryptochromes are not as essential as we thought for magnetoreception.

That shows cells can, at least in a laboratory, sense magnetic fields through other ways."

The discovery could help explain why human cells show sensitivity to magnetic fields in the lab. The form of cryptochrome present in the cells of our species' retina has proved capable of magnetoreception at a molecular level when expressed in fruit flies.

However, this doesn't mean humans utilize that function, nor is there evidence that cryptochrome guides our cells to line up along magnetic fields in the lab.

Tissue engineering: Developing bioinspired multi-functional tendon-mimetic hydrogels

Materials scientists work to develop advanced biological materials for medical devices and tissue engineering platforms to emulate natural biological tissue architectures via materials engineering. However, the natural tissue architecture has a variety of characteristics that are difficult to synthetically replicate. The architecture of tendons relies on the load-bearing capacities of the musculoskeletal system to provide biophysical cues that translate into cellular behaviors via interfacial interactions. In the past decade, researchers had devoted extensive research efforts to engineer tendon-mimetic materials with high structural anisotropy.

In a new report now published in Science Advances,  a research team in physics, mechanical engineering, electrical and electronic engineering reported the development of multifunctional tendon-mimetic hydrogels by assembling aramid nanofiber composites. 

The anisotropic composite hydrogels (ACH) contained stiff nanofibers and soft polyvinyl alcohol moieties to mimic biological interactions that typically occur between collagen fibers and proteoglycans  in tendons. The team was bioinspired by natural tendons to develop hydrogels with a high elastic modulus, strength and fracture toughness.

The researchers biofunctionalized these material surfaces with bioactive molecules to present biophysical cues to impart behavioral similarities to those of cell attachment. Additionally, the soft bioelectronic components integrated on the hydrogels facilitated a variety of physiological benefits. Based on the outstanding functionality of the tendon-mimetics, the team envisioned broader applications of the materials in advanced tissue engineering to form implantable prosthetics for human-machine interactions.

Mingze Sun et al, Multifunctional tendon-mimetic hydrogels, Science Advances (2023). DOI: 10.1126/sciadv.ade6973

Jeong-Yun Sun et al, Highly stretchable and tough hydrogels, Nature (2012). DOI: 10.1038/nature11409

Study finds common artificial sweetener linked to higher rates of heart attack and stroke

New research showed that erythritol, a popular artificial sweetener, is associated with an increased risk of heart attack and stroke. Findings were published today in Nature Medicine.

Researchers studied more than 4,000 people in the U.S. and Europe and found those with higher blood erythritol levels were at elevated risk of experiencing a major adverse cardiac event such as heart attack, stroke or death. They also examined the effects of adding erythritol to either whole blood or isolated platelets, which are cell fragments that clump together to stop bleeding and contribute to blood clots. Results revealed that erythritol made platelets easier to activate and form a clot. Pre-clinical studies confirmed ingestion of erythritol heightened clot formation.

Artificial sweeteners, such as erythritol, are common replacements for table sugar in low-calorie, low-carbohydrate and "keto" products. Sugar-free products containing erythritol are often recommended for people who have obesity, diabetes or metabolic syndrome and are looking for options to help manage their sugar or calorie intake. People with these conditions also are at higher risk for adverse cardiovascular events like heart attack and stroke.

Erythritol is about 70% as sweet as sugar and is produced through fermenting corn. After ingestion, erythritol is poorly metabolized by the body. Instead, it goes into the bloodstream and leaves the body mainly through urine. The human body creates low amounts of erythritol naturally, so any additional consumption can accumulate.

Measuring artificial sweeteners is difficult and labeling requirements are minimal and often do not list individual compounds. Erythritol is "Generally Recognized As Safe (GRAS)" by the FDA, which means there is no requirement for long-term safety studies.

The authors note the importance of follow-up studies to confirm their findings in the general population. The study had several limitations, including that clinical observation studies demonstrate association and not causation.

This study shows that when participants consumed an artificially sweetened beverage with an amount of erythritol found in many processed foods, markedly elevated levels in the blood are observed for days—levels well above those observed to enhance clotting risks. It is important that further safety studies are conducted to examine the long-term effects of artificial sweeteners in general, and erythritol specifically, on risks for heart attack and stroke, particularly in people at higher risk for cardiovascular disease.

 Stanley Hazen, The artificial sweetener erythritol and cardiovascular event risk, Nature Medicine (2023). DOI: 10.1038/s41591-023-02223-9. www.nature.com/articles/s41591-023-02223-9

Tiny environmental plastic particles in mom's food reach unborn children

Nanoscale plastic particles like those that permeate most food and water pass from pregnant rats to their unborn children and may impair fetal development, according to a  study that suggests the same process happens in humans.

Erosion chips microscopic particles off the billions of tons of plastics that are exposed to the elements in the environment. These particles mix with the food we eat and the air we breathe. A typical person ingests a credit card's worth of them every week.

Previous studies in pregnant laboratory animals have found adding these plastics to food impairs their offspring in numerous ways, but those studies didn't determine whether mothers passed the plastics to their children in utero.

The study provided specially marked nanoscale plastics to five pregnant rats. Subsequent imaging found that these nanoplastic particles permeated not only their placentas but also the livers, kidneys, hearts, lungs and brains of their offspring.

These findings demonstrate that ingested nanoscale polystyrene plastics can breach the intestinal barrier of pregnant mammals, the maternal-fetal barrier of the placenta and all fetal tissues. Future studies will investigate how different types of plastics cross cell barriers, how plastic particle size affects the process and how plastics harm fetal  development, the researchers said.

 Chelsea M. Cary et al, Ingested Polystyrene Nanospheres Translocate to Placenta and Fetal Tissues in Pregnant Rats: Potential Health Implications, Nanomaterials (2023). DOI: 10.3390/nano13040720

Researchers discover the mechanism by which tumor cells become resistant to chemotherapy in colorectal cancer

 Platinum-based chemotherapy, which is used to treat advanced colorectal cancer, accumulates in the healthy cells surrounding the cancer cells and, as a result, can reduce tumor sensitivity to treatment. This is demonstrated by a study published in the journal Nature Communications.

 A large number of cancer patients are treated with platinum-based therapy. However, many tumors are capable of developing resistance to treatment. In this study, the researchers examined tumor samples from patients and pre-clinical models of colorectal cancer to better understand the resistance to platinum-based therapy. They observed that platinum accumulates prominently in the healthy cells that surround the cancer cells, particularly in fibroblasts, the cells that contribute to tissue formation. Furthermore, this accumulation persists for more than two years after treatment has been completed. This discovery was made using techniques developed in geology and applied to biological samples.

The effect of platinum on fibroblasts
The researchers were able to demonstrate how the accumulation of platinum in the fibroblasts induced the activation of certain genes associated with a poor response to chemotherapy and tumor progression. Among them, the TGF-β protein redirected these fibroblasts to support cancer cells aggressiveness and resistance to treatment. 

There are currently no predictive biomarkers of benefit from chemotherapy in colorectal cancer. The analysis of about thirty patients before and after chemotherapy presented in this study reveals that periostin levels are an indicator of TGF-β activity in fibroblasts and serve as a robust marker of response to chemotherapy. Indeed, treatment benefit was significantly reduced in patients with elevated periostin levels before and/or after chemotherapy. Accordingly, chemotherapy was found to be less effective in tumors with high levels of periostin in pre-clinical colorectal cancer models.

The researchers are now working on developing a novel approach to improve the efficacy of chemotherapy in colorectal cancer.

This study is an important step toward understanding why chemotherapy does not work the same way in all cancer patients, and how to prevent or reverse resistance. This work is also essential in demonstrating that cancer treatment must take into account not only the cancer cells but also the healthy cells in the tumor. The next critical step will be to develop pharmacological strategies that act on the cancer cell and modulate the microenvironment in favor of tumor elimination.

 Jenniffer Linares et al, Long-term platinum-based drug accumulation in cancer-associated fibroblasts promotes colorectal cancer progression and resistance to therapy, Nature Communications (2023). DOI: 10.1038/s41467-023-36334-1