Researchers show water has multiple liquid states

An international team of researchers has shown that water can exist in two different liquid states—a finding that can explain many of water's anomalous properties.

The possibility that water could exist in two different liquid states was proposed approximately 30 years ago, based on results obtained from computer simulations. This hypothesis has been one of the most important questions in the chemistry and physics of water, and a controversial scenario since its beginnings. This is because experiments that can access the two liquid states in water have been very challenging due to the apparently unavoidable ice formation at the conditions where the two liquids should exist.

The usual "liquid" state of water that we are all familiar with corresponds to liquid water at normal temperatures (approximately 25 degrees C). However, a new research paper shows that water at low temperatures (approximately -63 degrees C) exists in two different liquid states, a low-density liquid at low pressures and a high-density liquid at high pressures. These two liquids have noticeably different properties and differ by 20% in density. The results imply that at appropriate conditions, water should exist as two immiscible liquids separated by a thin interface similar to the coexistence of oil and water.

Because water is one of the most important substances on Earth—the solvent of life as we know it—its phase behaviour plays a fundamental role in different fields, including biochemistry, climate, cryopreservation, cryobiology, material science, and in many industrial processes where water acts as a solvent, product, reactant, or impurity. It follows that unusual characteristics in the phase behaviour of water, such as the presence of two liquid states, can affect numerous scientific and engineering applications.

Experimental observation of the liquid-liquid transition in bulk supercooled water under pressure. Science (2020). science.sciencemag.org/lookup/ … 1126/science.abb9385

https://phys.org/news/2020-11-multiple-liquid-states.html?utm_sourc...

Undesirable rejection mechanism identified in stem cell transplantation

In the treatment of leukemia, stem cell transplantation subsequent to chemotherapy and radiation can often engender severe adverse inflammatory reactions—especially in the skin or in the gut, since these so-called barrier organs are more frequently affected. Up until now, the reason for this was unclear till now. Scientists now identified an immune mechanism that is partially responsible for this.

The term leukemia is used to describe a group of malignant diseases of the haematopoietic system, in which precursors of the white blood cells (leucocytes) proliferate uncontrollably. Chemotherapy and radiotherapy are used to destroy the abnormal blood cells, which are then replaced by means of a stem cell transplant. In leukemia, the transplantation of healthy bone marrow stem cells or haematopoietic stem cells is often the only hope of recovery for patients. The process involves "replacing" all the recipient's blood cells that were previously destroyed by the treatment with donor cells.

However, the MedUni Vienna dermatologists have now found that there are so-called skin-resident and inactive T cells in the endogenous immune system that survive chemotherapy and radiotherapy intact and go on to survive for a further ten years between and beneath the epithelial cells of the skin, while the circulating T cells are destroyed.

"We were able to demonstrate that T cells surviving in the skin tissue are responsible for the inflammatory reaction following a stem cell transplant. These phenomena often occur within the first 100 days and can cause anything from mild eczema through to extensive fibrosis, hardening of the tissue, or blistering on the surface of the skin. In other words, the endogenous T cells attack the recipient (host) following stem cell transplantation." In specialist jargon, the condition is also referred to as Graft versus Host Disease (GvHD), and, for the first time, this study identified an inverse "Host-versus-graft reaction."

There were also cases in which the donor T cells further "supported," and thus intensified, this reaction. Affected patients are treated with cortisone, which causes an additional burden for patients who are already immunosuppressed following the transplantation. The study found that in patients who do not develop graft-versus-host disease, tissue-resident T cells remaining after treatment even proved to be beneficial to the recipient, in that they assumed their role in immune defense and protecting against infection.

In the future, the exemplary study results could lead to new treatment strategies that help to avoid, or at least to minimize, undesirable and violent inflammatory reactions following stem cell transplants by manipulating the recipient's inactive T cells in advance. In addition, the manipulation of tissue-resident T cells might lead to new therapeutic approaches for other chronic inflammatory skin diseases, such as psoriasis or neurodermatitis.

Johanna Strobl et al. Long-term skin-resident memory T cells proliferate in situ and are involved in human graft-versus-host disease, Science Translational Medicine (2020). DOI: 10.1126/scitranslmed.abb7028

https://medicalxpress.com/news/2020-11-undesirable-mechanism-stem-c...

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The fundamental chemistry behind electrocatalytic water splitting

https://phys.org/news/2020-11-fundamental-chemistry-electrocatalyti...

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New system can sterilize medical tools using solar heat

Gut microbiome manipulation could result from virus discovery

Scientists have discovered how a common virus in the human gut infects and takes over bacterial cells – a finding that could be used to control the composition of the gut microbiome, which is important for human health.

The Rutgers co-authored research, which could aid efforts to engineer beneficial bacteria that produce medicines and fuels and clean up pollutants.
CrAssphages are the most abundant viruses infecting bacteria in the human gut. As such, they likely control our intestinal community of microbes (the microbiome).Understanding how these tiny viruses infect bacteria may allow scientists to control and manipulate the makeup of the microbiome, either by increasing the proportion of beneficial bacteria in our intestines or decreasing the number of harmful bacteria, thus promoting health and fighting disease.
Scientists found that crAssphages use their own enzyme (an RNA polymerase) to make RNA copies of their genes. RNA has the genetic information to make proteins. All cells, ranging from bacterial to human, use such enzymes to make RNA copies of their genes. And these enzymes are very similar in all living matter, implying that they’re ancient and related by common ancestry.
The atomic structure of a crAssphage enzyme is distinct from other RNA polymerases but closely resembles an enzyme in humans and other higher organisms that is involved in RNA interference. Such interference silences the function of some genes and may lead to certain diseases.

This is a startling result. It suggests that enzymes of RNA interference, a process that was thought to occur only in cells of higher organisms, were ‘borrowed’ from an ancestral bacterial virus early in evolution. The result provides a glimpse of how cells of higher organisms evolved by mixing and matching components of simpler cells and even their viruses.

In addition to deep evolutionary insights, phage (viral) enzymes such as crAssphage RNA polymerase may be used in synthetic biology to generate genetic circuits that do not exist in nature.

https://www.rutgers.edu/news/gut-microbiome-manipulation-could-resu...

https://researchnews.cc/news/3670/Gut-microbiome-manipulation-could...

Scientists identify brain cells that drive wakefulness and resist general anesthetics
Neuroscientists don’t know precisely what brain circuits control wakefulness and sleep, nor exactly how drugs for general anesthesia affect those circuits. But a new study from Penn Medicine researchers brings neuroscience a step closer to solving that important conundrum.

A team of researchers from the Perelman School of Medicine at the University of Pennsylvania, in a study published online Nov. 13 in Current Biology, identified a population of neurons in the hypothalamus region of the brain that keeps mice from sleeping when they normally would when they are activated. Activating these neurons also “wakes” them from ongoing exposure to inhaled anesthetics like isoflurane or sevoflurane, and even helps maintain the alert state when animals are dosed with anesthetics.

The study also supports a hypothesis long debated by neuroscientists: that the parts of the brain regulating sleep and waking are also capable of regulating the brain’s response to general anesthetics.

https://www.pennmedicine.org/news/news-releases/2020/november/scien...

https://researchnews.cc/news/3673/Scientists-identify-brain-cells-t...

Your Tears Might Save Your Life Someday

They could ultimately be used to find diseases the way blood tests do now—but cheaper and more easily

At any given moment, about seven microliters of tears are present in each of our eyes—about a tenth of a drop of water. You might think of them as nothing more than salty water, but it’s more accurate to think if them filtered blood; they deliver oxygen and nutrients to our eyes, removing waste, serving as the first line of defense against pathogens and helping to heal injuries.

Tears also contain traces of the various chemicals originally present in blood, some of which serve as markers of illness—glucose, for example, which can signal diabetes, or enzymes that point to possible liver disease. That’s a primary reason doctors order blood tests. But it also that means that physicians—and maybe, in the near future, you—can look for indicators of illness by looking at your tears.

https://www.scientificamerican.com/article/your-tears-might-save-yo...

How rotavirus causes severe gastrointestinal disease

Rotavirus is a major cause of diarrhea and vomiting, especially in children, that results in approximately 128,000 deaths annually. The virus triggers the disease by infecting enterocyte cells in the small intestine, but only a fraction of the susceptible cells has the virus. In the mid-90s, scientists proposed that the small portion of infected cells promotes severe disease by sending out signals that disrupt the normal function of neighbouring uninfected cells, but the nature of the signal has remained a mystery.

In the current study published in the journal Science, a team led by researchers at Baylor College of Medicine discovered that rotavirus-infected cells release signaling molecules, identified as adenosine diphosphate (ADP), which binds its cellular receptor P2Y1 on neighboring cells. Activating P2Y1 by ADP results in signals called intercellular calcium waves in these uninfected cells. Disrupting ADP binding to its receptor reduced the severity of diarrhea in a mouse model of the disease, suggesting that targeting the P2Y1 may be an effective strategy to control viral diarrhea in human populations.

Further studies revealed previously unknown roles of ADP on rotavirus infection and replication, shining a spotlight on ADP as an important trigger of the multiple factors involved in severe diarrhea and vomiting caused by rotavirus. For instance, the researchers found evidence that ADP signaling increases rotavirus infection, the expression of inflammatory cytokine IL1-alpha and the secretion of serotonin, an inducer of diarrhea. ADP signaling also increases the expression of enzymes that produce prostaglandin and nitric oxide, potentially causing the increases in those compounds observed in rotavirus infection. Preventing ADP signaling and intercellular calcium waves reduced the production of the compounds mentioned above.

 Alexandra L. Chang-Graham et al, Rotavirus induces intercellular calcium waves through ADP signaling, Science (2020). DOI: 10.1126/science.abc3621

https://medicalxpress.com/news/2020-11-rotavirus-severe-gastrointes...

**In a First, Scientists Say They've Partially Reversed a Cellular Aging Process in Humans

Every time a cell inside your body replicates, a slither of your youth crumbles to dust. This occurs via the shortening of telomeres, structures that 'cap' the tips of our chromosomes.

Now, scientists in Israel say they've been able to reverse this process and extend the length of telomeres in a small study involving 26 patients.

The participants sat in a hyperbaric oxygen chamber for five 90 minutes sessions per week over three months, and as a result, some of their cell's telomeres were extended by up to 20 percent.

It's an impressive claim - and something many other researchers have attempted in the past without success. But of course it's worth flagging that this is a small sample size, and the results will need to be replicated before we can get too excited. 

However, the fact that hyperbaric oxygen therapy appears to affect telomere length is a compelling link worth investigating further. 

Telomeres are repeating chunks of code that act as the DNA equivalent of the plastic or metal aglet capping the end of a shoelace.

They copy themselves along with the rest of the chromosomes whenever a cell divides. Yet with every replication, tiny fragments of code from the very tip of the sequence fail to make it into the new copy, leaving the freshly minted chromosome a touch shorter than its predecessor.

As anybody who has lost the cap of their shoelace knows, it doesn't take long for the shoelace to lose its integrity. Similarly, shorter telomeres put sequences further down the chromosome at higher risk of hazardous mutations.

These mutations coincide with changes that predispose us to a bunch of age-related conditions, not least of all diseases such as cancer.

That's not necessarily to say that we age because our telomeres shrink, but there is a connection between telomere length and health that researchers are keen to investigate further.

"Longer telomeres correlates with better cellular performance. There are plenty of ways to accelerate the erosion of our telomeres. Failing to get adequate sleep could do it, as might chowing down on too much processed food, and maybe even having kids.
Slowing down the loss takes a bit more effort, but engaging in regular exercise and eating well are sound bets if you want your chromosomes to remain as long as possible.

A real achievement would be to flip our chromosomal hourglass completely and return lost sections of telomere. The fact that high-turnover tissues lining our gut do this naturally using an enzyme called telomerase has fuelled research over the years.

There have been plenty of milestones in attempts to achieve this task. Gene therapy in mice has shown it could one day be feasible in humans. More recently, stem cells from a supercentenarian woman had their telomeres completely reset outside of her body.

Some studies have found potential for tiny increases of maybe a few percent with provision of nutritional supplements such as vitamin D.

https://www.aging-us.com/article/202188/text

https://www.sciencealert.com/oxygen-therapy-found-to-turn-back-the-...

** Asymptomatic Children Can Spread Malaria to Mosquitoes

Children infected with malaria can become 'superspreaders' and pass the parasite to droves of local mosquitoes, even if the kids never develop symptoms of the disease, a new study suggests. 

Since this disease is passed from humans to mosquitoes and then back again, rather than from person to person, this finding is worrisome. If malaria goes untreated in these asymptomatic children, the parasites will continue to circulate among mosquitoes, even in places that employ intensive malaria controls like insecticides, bednets, and free diagnostic tests and treatments. According to new research, presented Wednesday (Nov. 18) at the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), even a small number of infected children can transmit malaria parasites to a mob of mosquitoes, which can then go on to infect more humans. From their new research in Uganda, the researchers concluded that asymptomatic children between ages 5 and 15 are the main source of infection for local mosquitoes in the region they studied. Some of these children were so-called superspreaders, meaning they infected a much larger number of mosquitoes than others; in experiments where mosquitoes were fed blood samples from infected people, more than 60 percent of the resulting mosquito infections could be traced back to just four asymptomatic children, two of whom were school-age. The other two superspreaders were ages 3 and 4.

Despite some children becoming infected with multiple malaria clones during the study, these kids never fell ill and continued to lead a "normal life … somehow living with all these parasites

https://www.livescience.com/asymptomatic-children-malaria-reservoir...

3D-printed, lifelike heart models could help train tomorrow’s surgeons

Astronomers discover new 'fossil galaxy' buried deep within the Milky Way

Scientists working with data from the Sloan Digital Sky Surveys' Apache Point Observatory Galactic Evolution Experiment (APOGEE) have discovered a "fossil galaxy" hidden in the depths of our own Milky Way.

The proposed fossil galaxy may have collided with the Milky Way ten billion years ago, when our galaxy was still in its infancy. Astronomers named it Heracles, after the ancient Greek hero who received the gift of immortality when the Milky Way was created.

The remnants of Heracles account for about one third of the Milky Way's spherical halo. But if stars and gas from Heracles make up such a large percentage of the galactic halo, why didn't we see it before? The answer lies in its location deep inside the Milky Way.

"To find a fossil galaxy like this one, we had to look at the detailed chemical makeup and motions of tens of thousands of stars. That is especially hard to do for stars in the center of the Milky Way, because they are hidden from view by clouds of interstellar dust. APOGEE lets us pierce through that dust and see deeper into the heart of the Milky Way than ever before.

APOGEE does this by taking spectra of stars in near-infrared light, instead of visible light, which gets obscured by dust. Over its ten-year observational life, APOGEE has measured spectra for more than half a million stars all across the Milky Way, including its previously dust-obscured core and finally discovered this fossil galaxy .

"Evidence from APOGEE for the Presence of a Major Building Block of the Halo Buried in the Inner Galaxy," Danny Horta et al., 2020 Nov. 20, Monthly Notices of the Royal Astronomical Society: arxiv.org/abs/2007.10374].

https://phys.org/news/2020-11-astronomers-fossil-galaxy-deep-milky....

Fake news and misinformation kill: How can you trust what you are told about Covid-19?

**Virus evolution could undermine a COVID-19 vaccine – but this can be stopped

https://theconversation.com/virus-evolution-could-undermine-a-covid...

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Ultrasound Reveals Parasitic Worms Squirming Around Inside Man's Stomach in Delhi

Previewed Reality: A system that allows users to predict future changes in their environment

When robots and humans interact in a shared environment, it is important for them to move in ways that prevent collisions or accidents. To reduce the risk of collisions, roboticists have developed numerous of techniques that monitor an environment, predict the future actions of humans moving in it, identify safe trajectories for a robot and control its movements accordingly.

Researchers at Kyushu University in Japan recently created a system that allows human users to forecast future changes in their environment, which could then inform their decisions and guide their actions. 

To collect information about the position of different objects, robots and humans in a shared environment, the researchers used a number of strategically placed sensors, including optical trackers and an RGB-D camera. The optical trackers monitored the movements of objects or robots, while the RGB-D camera mainly tracked human actions.

The data gathered by the sensors was then fed to a motion planner and a dynamics simulator. Combined, these two system components allowed the researchers to forecast changes in a given environment and synthesize images of events that are likely to occur in the near future, from the viewpoint of a specific human.

Human users could then view these synthesized images simply by wearing a VR headset or an AR display. On the headset or display, the images were layed over those of a user's actual surroundings, in order to clearly illustrate the changes that could take place in the future.

Asuka Egashira et al. Near-future perception system: Previewed Reality, Advanced Robotics (2020). DOI: 10.1080/01691864.2020.1829041

https://techxplore.com/news/2020-11-previewed-reality-users-future-...

Social bacteria build shelters using the physics of fingerprints

Forest-dwelling bacteria known for forming slimy swarms that prey on other microbes can also cooperate to construct mushroom-like survival shelters known as fruiting bodies when food is scarce. Now a team at Princeton University has discovered the physics behind how these rod-shaped bacteria, which align in patterns like those on fingerprint whorls and liquid crystal displays, build the layers of these fruiting bodies.

( See pic above )

In some ways, these bacteria  are teaching us new kinds of physics. These questions exist at the intersection of physics and biology. And you need to understand both to understand these organisms.

Myxococcus xanthus, or Myxo for short, is a bacterial species capable of surprisingly cooperative behaviors. For example, large numbers of Myxo cells  come together to hunt other bacteria by swarming toward their prey in a single undulating mass.

When food is scarce, however, the rod-like cells stack atop one another to form squishy growths called fruiting bodies, which are hideaways in which some of the Myxo cells transform into spores capable of rebooting the population when fresh nutrients arrive. But until now, scientists haven't understood how the rods acquire the ability to begin climbing on top of each other to build the droplet-like structures.

To find out more about how these bacteria behave, the researchers set up a microscope capable of tracking Myxo's actions in three dimensions. The scientists recorded videos of the rod-shaped microbes, which pack closely together like stampeding wildebeest, rushing across the microscope dish in swaths that swirl around each other, forming fingerprint-like patterns.

When two swaths meet, the researchers observed, the point of intersection was exactly where the new layer of cells started to form. The bacteria started to pile up and created a situation where the only direction to go was up. these bacteria are exploiting particular points of the cell alignment where stresses build that enable the colony to construct new cell layers, one on top of the other. And that's ultimately how this colony responds to starvation. Researchers call the points where the massing cells collide "topological defects," a term that refers to the mathematics that describe these singular points. Topology is the branch of mathematics that finds similarities between objects such as teacups and donuts, because one can be stretched or deformed into the other.

Myxo bacterial cells behave much like liquid crystals, the fluids found in smartphone screens, which are made of rod-shaped molecules. Unlike passive liquid crystals, however, Myxo rods are alive and can crawl. The bacteria most likely have evolved to take advantage of both passive and active factors to build the fruiting bodies.

The combination of physics and biology training among the researchers enabled them to recognize new theoretical insights into how the vertical layers form.

Understanding ion channel inhibition to open doors in drug discovery

Scientists have discovered how drug-like small molecules can regulate the activity of therapeutically relevant ion channels—and their findings could transform ongoing drug development efforts.

A major mechanism by which cells communicate with their environment is the movement of metal ions through channels located within their cell membranes.

The new study by researchers at the University of Leeds, published today in Communications Biology, provides detailed insight into the regulation of TRPC5 ion channels, which allow positively charged ions such as calcium, sodium and potassium to flow in and out of cells.

TRPC5 channels are considered potential therapeutic targets for the treatment of a range of conditions, including anxiety, kidney disease and cardiovascular disease.

Cryo-EM structures of human TRPC5 reveal interaction of a xanthine-based TRPC1/4/5 inhibitor with a conserved lipid binding site, Communications Biology (2020).

https://phys.org/news/2020-11-ion-channel-inhibition-doors-drug.htm...

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Scientists observe directed energy transport between neighboring molecules in a nanomaterial

When light falls on a material, such as a green leaf or the retina, certain molecules transport energy and charge. This ultimately leads to the separation of charges and the generation of electricity. Molecular funnels, so-called conical intersections, ensure that this transport is highly efficient and directed.

An international team of physicists has now observed that such conical intersections also ensure a directed energy transport between neighboring molecules of a nanomaterial. Theoretical simulations have confirmed the experimental results. Until now, scientists had observed this phenomenon only within one molecule. In the long term, the results could help to develop more efficient nanomaterials for organic solar cells, for example. 

 Antonietta De Sio et al, Intermolecular conical intersections in molecular aggregates, Nature Nanotechnology (2020). DOI: 10.1038/s41565-020-00791-2

https://phys.org/news/2020-11-scientists-energy-neighboring-molecul...

Nature's toolkit for killing viruses and bacteria

Tiny infectious microbes—from the virus that causes COVID-19 to waterborne bacteria—kill millions of people around the world each year. Now engineers are studying how zinc oxide surfaces and natural hydrodynamic churning have the power to kill pathogens first.

Reseachers now  submerged clean zinc in hot water for 24 hours, which formed a zinc oxide surface covered in sharp nanoneedles. Then they introduced E. coli bacteria.

The surface kills almost all bacteria cultured on top of it very efficiently. And the biggest surprise? When sitting in contaminated water, the surface kills all waterborne E. coli within three hours—even bacteria it didn't touch.

This water disinfection at a distance works because the process generates a reactive oxygen species, which damages the cell walls of bacteria. 

This surface can be used to disinfect water in remote areas at a very low cost. "The fabrication technique is environmentally friendly, simple, and economical."

Environmental Friendly and Scalable Fabrication of Antibacterial ZnO-Nanostructured Surfaces, meetings.aps.org/Meeting/DFD20/Session/Z01.12

https://phys.org/news/2020-11-nature-toolkit-viruses-bacteria.html?...

**Choked, strangled and drowned. How balloons and plastic bags are killing marine animals

Balloons, plastic bags, recreational fishing line and food wrappers are killing thousands of marine animals as they eat plastic items that later perforate internal organs, or become entangled and drown.

Researchers found that plastics ranged in size and type, from microplastics that were perforating the gastrointestinal tract of a baby sea turtle to DVD cases and huge plastic sheets that had been swallowed by whales.

Scientists estimate that 15 million tons of plastic wash into the ocean every year, or about two garbage trucks' worth of plastic every minute. With plastic production expected to quadruple by the year 2050, some expect there will be more plastic than fish in the world's oceans.

The biggest problem was animals consuming plastic. Marine animals often mistake plastic for food or inadvertently swallow plastic while feeding or swimming.

"The result is that it can obstruct their digestion or lacerate their intestines, and all of this can interfere with their ability to feed and obtain the nourishment they need. These problems can lead to an animal's starvation and death.

https://phys.org/news/2020-11-strangled-balloons-plastic-bags-marin...

Energy drinks can raise stillbirth risk and caffeine guidance confuses mums-to-be, new research warns

Stillbirth experts warn that expectant parents need to know more about caffeine, as a new study from Tommy’s Maternal and Fetal Health Research Centre at the university of Manchester shows 1 in 20 women increased their intake during pregnancy, despite evidence that some caffeinated drinks can endanger babies’ lives.

Scientists from Tommy’s stillbirth research centre at the University of Manchester studied more than 1,000 mothers across 41 UK hospitals between 2014 and 2016. They combined information typically used to measure stillbirth risk with an interviewer-led questionnaire about mothers’ consumption of various caffeinated drinks, as well as other risk factors like alcohol and cigarettes that have confused previous studies, to see if and when stillbirth may have been linked to caffeine.

When caffeine crosses the placenta, babies can’t process it like adults, and it can endanger their lives. Current NHS guidance is to keep daily caffeine intake below 200mg when pregnant, while the World Health Organization (WHO) cites 300mg as the safe limit. This new study reports a 27% increase in stillbirth risk for each 100mg consumed, suggesting that safe limits in these guidelines need to be reconsidered.

Energy drinks had the most impact, leading to 1.85x higher stillbirth risk, followed by instant coffee (1.34x) and cola (1.23x). Researchers noted that it wasn’t possible to separate the impact of caffeine from that of sugar in cola and chemicals like taurine in energy drinks, so more detailed investigation is needed.

https://www.manchester.ac.uk/discover/news/energy-drinks-can-raise-...

https://researchnews.cc/news/3734/Energy-drinks-can-raise-stillbirt...

Deep learning helps robots grasp better

**Cocoa flavanols boost brain oxygenation, cognition in healthy adults

The brains of healthy adults recovered faster from a mild vascular challenge and performed better on complex tests if the participants consumed cocoa flavanols beforehand, researchers report in the journal Scientific Reports. In the study, 14 of 18 participants saw these improvements after ingesting the flavanols.

Previous studies have shown that eating foods rich in flavanols can benefit vascular function, but this is the first to find a positive effect on brain vascular function and cognitive performance in young healthy adults.

Flavanols are small molecules found in many fruits and vegetables, and cocoa, too. They give fruits and vegetables their bright colours, and they are known to benefit vascular function.

About two hours after consuming the cocoa, participants breathed air with 5% carbon dioxide—about 100 times the normal concentration in air. This is a standard method for challenging brain vasculature to determine how well it responds.

Researchers also challenged participants with complex tasks that required them to manage sometimes contradictory or competing demands.

Most of the participants had a stronger and faster brain oxygenation response after exposure to cocoa flavanols than they did at baseline or after consuming cocoa lacking flavanols, the researchers found. 

After ingesting the cocoa flavanols, participants also performed better on the most challenging cognitive tests, correctly solving problems 11% faster than they did at baseline or when they consumed cocoa with reduced flavanols. There was no measurable difference in performance on the easier tasks, however.

"This suggests that flavanols might only be beneficial during cognitive tasks that are more challenging.

'Dietary flavanols improve cerebral cortical oxygenation and cognition in healthy adults,' Scientific Reports (2020). DOI: 10.1038/s41598-020-76160-9

https://medicalxpress.com/news/2020-11-cocoa-smarter.html?utm_sourc...

Antimicrobial soap additive worsens fatty liver disease in mice

Researchers found evidence that triclosan—an antimicrobial found in many soaps, toothpastes and other household items—worsens fatty liver disease in mice fed a high-fat diet.

The study also reveals also details the molecular mechanisms  by which triclosan disrupts metabolism and the gut microbiome, while also stripping away liver cells' natural protections. Triclosan's increasingly broad use in consumer products presents a risk of liver toxicity for humans.

The study shows that common factors that we encounter in every-day life—the ubiquitous presence of triclosan, together with the prevalence of high consumption of dietary fat —constitute a good recipe for the development of fatty liver disease in mice.

In a 2014 mouse study, the team found triclosan exposure promoted liver tumor formation by interfering with a protein responsible for clearing away foreign chemicals in the body. In the latest study, the researchers fed a high-fat diet to mice with type 1 diabetes. As previous studies have shown, the high-fat diet led to non-alcoholic fatty liver disease (NAFLD). In humans, NAFLD is an increasingly common condition that can lead to liver cirrhosis and cancer. Diabetes and obesity are risk factors for NAFLD. Some of the mice were also fed triclosan, resulting in blood concentrations comparable to those found in human studies. Compared to mice only fed a high-fat diet, triclosan accelerated the development of fatty liver and fibrosis. According to the study, here's what's likely happening: Eating a high-fat diet normally tells cells to produce more fibroblast growth factor 21, which helps protects liver cells from damage. Tukey and team discovered that triclosan messes with two molecules, ATF4 and PPARgamma, which cells need to make the protective growth factor. Not only that, the antimicrobial also disrupted a variety of genes involved in metabolism. In addition, the mice exposed to triclosan had less diversity in their gut microbiomes—fewer types of bacteria living in the intestines, and a makeup similar to that seen in patients with NAFLD. Less gut microbiome diversity is generally associated with poorer health. So far, these findings have only been observed in mice who ingested triclosan. But since these same molecular systems also operate in humans, the new information will help researchers better understand risk factors for NAFLD, and give them a new place to start in designing potential interventions to prevent and mitigate the condition.

Mei-Fei Yueh et al, Triclosan leads to dysregulation of the metabolic regulator FGF21 exacerbating high fat diet-induced nonalcoholic fatty liver disease, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2017129117

https://medicalxpress.com/news/2020-11-antimicrobial-soap-additive-...

COVID-19: Air quality influences the pandemic

The correlation between the high concentration of fine particles and the severity of influenza waves is well known to epidemiologists. An interdisciplinary team from the University of Geneva (UNIGE) and the ETH Zürich spin-off Meteodat investigated possible interactions between acutely elevated levels of fine particulate matter and the virulence of the coronavirus disease. Their results, published in the journal Earth Systems and Environment, suggest that high concentrations of particles less than 2.5 micrometers in size may modulate, or even amplify, the waves of SARS-CoV-2 contamination and explain in part the particular profile of the COVID-19 pandemic. The increase in fine particles is generally favored by air temperature inversions, characterized by fog situations, or by Saharan dust intrusions. The study provides preventive measures related to air pollution to limit future outbreaks of morbidity and mortality due to the coronavirus.

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India's love affair with coal cools as pressure grows on sector

Funding for coal projects in India has plunged for the second straight year, new figures showed Tuesday, as the world's second biggest coal importer weans itself off the dirty fuel.

Scientists find water microdroplets can transform into hydrogen peroxide when condensing on cold surfaces

In its bulk liquid form, whether in a bathtub or an ocean, water is a relatively benign substance with little chemical activity. But down at the scale of tiny droplets, water can turn surprisingly reactive,  researchers have discovered.

In microdroplets of water, just millionths of a meter wide, a portion of the H₂O molecules present can convert into a close chemical cousin, hydrogen peroxide, H₂O₂, a harsh chemical commonly used as a disinfectant and hair bleaching agent.

Stanford scientists first reported this unexpected behavior in forcibly sprayed microdroplets of water last year. Now in a new study, the research team has shown the same Jekyll-and-Hyde transformation happens when microdroplets simply condense from the air onto cold surfaces. The new results suggest that water's hydrogen peroxidetransformation is a general phenomenon, occurring in fogs, mists, raindrops and wherever else microdroplets form naturally.

The surprising discovery could lead to greener methods for disinfecting surfaces or promoting chemical reactions.

Jae Kyoo Lee et al. Condensing water vapor to droplets generates hydrogen peroxide, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2020158117

https://phys.org/news/2020-11-scientists-microdroplets-hydrogen-per...

Oxford vaccine: How did they make it so quickly?

Ten years' vaccine work achieved in about 10 months. Yet no corners cut in designing, testing and manufacturing.

https://www.bbc.com/news/health-55041371

Scientists Detect 'Superbolts' 1,000 Times Brighter Than Typical Lightning Strikes

scientists have just detected a new extreme in hotspots of lightning activity called 'superbolts': intense lightning strikes that shine up to 1,000 times brighter than typical lightning strikes. 

The observations come from researchers at the US Los Alamos National Laboratory, who used satellites to measure the extreme lightning events. The results force a rethink on what constitutes a superbolt, and shed new light on how and where superbolts originate. Unlike ground-based monitoring systems, which detect radio waves, the GLM measures the total brightness (optical energy) of lightning bolts within clouds, between clouds, plus lightning that strikes the ground.

There's also the question of whether superbolts are supercharged by some unique phenomenon, or if they're just bigger, brighter strikes of the usual lightening variety.

Understanding these extreme events is important because it tells us what lightning is capable of.

The researchers combed two years of data for lightning strikes that shone 100 times brighter than a typical bolt detected from space, and found about 2 million events intense enough to be called a superbolt – roughly one in every 300 lightning events. When the researchers raised the bar to lightning events at least 1,000 times brighter than an ordinary lightning strike, they identified key hotspots of energetic superbolt activity.

Scientists found one lightning stroke that exceeded 3 terawatts of power – thousands of times stronger than ordinary lightning detected from space.

The most powerful superbolts (producing more than 350 gigawatts of power) resulted from rare positively charged cloud-to-ground events, rather than negatively charged cloud-to-ground events, which characterises most lightning strikes.

The results also showed that superbolts often occur over the ocean and tend to spark from megaflashes, which stretch hundreds of miles horizontally from tip to tail.

Oceanic storm systems, particularly during the winter, and especially those located around Japan are shown to produce these intense superbolts.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033378

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033377

https://www.sciencealert.com/study-finds-superbolts-shine-1000-time...

A pocket cooling device based on a cascade mechanism

Recent technological advances have enabled the development of increasingly compact and flexible devices. This includes wearable or portable technology.

Researchers  have recently devised a strategy that could enable the fabrication of portable, compact and flexible electrocaloric cooling devices. This strategy, outlined in a paper published in Nature Energy, is based on a four-layer cascade mechanism that enables a significant temperature lift in a user's surroundings.

This pocket cooling device designed is made of an electrocaloric polymer film. When voltage is applied to the polymer, the device heats up due to a significant entropy reduction. Conversely, when the voltage is removed, the device's temperature drops.

Yuan Meng et al. A cascade electrocaloric cooling device for large temperature lift, Nature Energy (2020). DOI: 10.1038/s41560-020-00715-3

https://techxplore.com/news/2020-11-pocket-cooling-device-based-cas...

Tunable coating allows hitch-hiking nanoparticles to slip past the immune system to their target

Nanoparticles are promising drug delivery tools, offering the ability to administer drugs directly to a specific part of the body and avoid the awful side effects so often seen with chemotherapeutics.

But there's a problem. Nanoparticles struggle to get past the immune system's first line of defense: proteins in the blood serum that tag potential invaders. Because of this, only about 1 percent of nanoparticles reach their intended target.

A team of researchers have now  developed an ionic forcefield that prevents proteins from binding to and tagging nanoparticles.

In mouse experiments, nanoparticles coated with the ionic liquid survived significantly longer in the body than uncoated particles and, surprisingly, 50 percent of the nanoparticles made it to the lungs. It's the first time that ionic liquids have been used to protect nanoparticles in the blood stream.

"The fact that this coating allows the nanoparticles to slip past serum proteins and hitch a ride on red blood cells is really quite amazing because once you are able to fight the immune system effectively, lots of opportunities open up.

"Protein-avoidant ionic liquid (PAIL)–coated nanoparticles to increase bloodstream circulation and drive biodistribution" Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abd7563

https://phys.org/news/2020-11-tunable-coating-hitch-hiking-nanopart...

Waste fishing gear threatens Ganges wildlife

Waste fishing gear in the River Ganges poses a threat to wildlife including otters, turtles and dolphins, new research shows.

The study says entanglement in fishing gear could harm species including the critically endangered three-striped roofed turtle and the endangered Ganges river dolphin.

Surveys along the length of the river, from the mouth in Bangladesh to the Himalayas in India, show levels of waste fishing gear are highest near to the sea.

Fishing nets—all made of plastic—were the most common type of gear found. local fishers revealed high rates of fishing equipment being discarded in the river—driven by short gear lifespans and lack of appropriate disposal systems.

"Ingesting plastic can harm wildlife, but our threat assessment focussed on entanglement, which is known to injure and kill a wide range of marine species."

The researchers used a list of 21 river species of "conservation concern" identified by the Wildlife Institute for India.

Sarah E. Nelms et al, Riverine plastic pollution from fisheries: Insights from the Ganges River system, Science of The Total Environment (2020). DOI: 10.1016/j.scitotenv.2020.143305

https://phys.org/news/2020-11-fishing-gear-threatens-ganges-wildlif...

Scientists discover potential method to starve the bacteria that cause tuberculosis

The infectious disease Tuberculosis (TB) is one of the leading causes of death worldwide.

Researchers have known for some time that the bacteria that causes TB (Mycobacterium tuberculosis) uses our body's cholesterol—a steroid—as a food source. Other relatives of the bacteria that do not cause disease share its ability to break down steroids. In this study scientists identified the structure of an enzyme (acyl CoA dehydrogenase) involved in steroid degradation in another member of the same bacteria family, called Thermomonospora curvata.

Determining the structure of enzymes that metabolize steroids moves scientists and pharmaceutical companies one step closer to creating drugs that can inhibit a similar enzyme found in M. tuberculosis, which would effectively starve TB of its food source. 

Alexander J. Stirling et al. A Key Glycine in Bacterial Steroid-Degrading Acyl-CoA Dehydrogenases Allows Flavin-Ring Repositioning and Modulates Substrate Side Chain Specificity, Biochemistry (2020). DOI: 10.1021/acs.biochem.0c00568

https://phys.org/news/2020-11-scientists-potential-method-starve-ba...

Researchers uncover the unique way stem cells protect their chromosome ends

Telomeres are specialized structures at the end of chromosomes which protect our DNA and ensure healthy division of cells. According to a new study from researchers at the Francis Crick Institute published in Nature, the mechanisms of telomere protection are surprisingly unique in stem cells.

For the last 20 years, researchers have been working to understand how telomeres protect chromosome ends from being incorrectly repaired and joined together because this has important implications for our understanding of cancer and aging.

In healthy cells, this protection is very efficient, but as we age our telomeres get progressively shorter, eventually becoming so short that they lose some of these protective functions. In healthy cells, this contributes to the progressive decline in our health and fitness as we age. Conversely, telomere shortening poses a protective barrier to tumor development, which cancer cells must solve in order to divide indefinitely.

In somatic cells, which are all the cells in the adult body except stem cells and gametes, we know that a protein called TRF2 helps to protect the telomere. It does this by binding to and stabilizing a loop structure, called a t-loop, which masks the end of the chromosome. When the TRF2 protein is removed, these loops do not form and the chromosome ends fuse together, leading to "spaghetti chromosomes" and killing the cell.

However, in this latest study, Crick researchers have found that when the TRF2 protein is removed from mouse embryonic stem cells, t-loops continue to form, chromosome ends remain protected and the cells are largely unaffected.

As embryonic stem cells differentiate into somatic cells, this unique mechanism of end protection is lost and both t-loops and chromosome end protection become reliant on TRF2. This suggests that somatic and stem cells protect their chromosome ends in fundamentally different ways.

Phil Ruis et al. TRF2-independent chromosome end protection during pluripotency, Nature (2020). DOI: 10.1038/s41586-020-2960-y

https://phys.org/news/2020-11-uncover-unique-stem-cells-chromosome....

Covid-19 pandemic could be stopped if at least 70% public wore face...
The Covid-19 pandemic could be stopped if at least 70 per cent of the public wore face masks consistently, according to research published in the journal Physics of Fluids. The study suggests that the type of material used and the duration of mask use play key roles in their effectiveness. While surgical masks were said to be more efficient, cloth masks could also slow transmission.

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Humans are polluting the environment with antibiotic-resistant bacteria, and scientists are  finding them everywhere

https://theconversation.com/humans-are-polluting-the-environment-wi...

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** Keyhole wasps may threaten aviation safety

Over a period of 39 months, invasive keyhole wasps (Pachodynerus nasidens) at the Brisbane Airport were responsible for 93 instances of fully blocked replica pitot probes—vital instruments that measure airspeed—according to a study published November 25 in the open-access journal PLOS ONE by Alan House of Eco Logical Australia and colleagues. As noted by the authors, the results underscore the importance of risk-mitigating strategies, such as covering pitot probes when aircraft arrive and setting up additional traps to intercept the wasps.

**Study revealing the secret behind a key cellular process refutes biology textbooks

New research has identified and described a cellular process that, despite what textbooks say, has remained elusive to scientists until now—precisely how the copying of genetic material that, once started, is properly turned off.

The finding concerns a key process essential to life: the transcription phase of gene expression, which enables cells to live and do their jobs.

During transcription, an enzyme called RNA polymerase wraps itself around the double helix of DNA, using one strand to match nucleotides to make a copy of genetic material—resulting in a newly synthesized strand of RNA that breaks off when transcription is complete. That RNA enables production of proteins, which are essential to all life and perform most of the work inside cells.

Just as with any coherent message, RNA needs to start and stop in the right place to make sense. A bacterial protein called Rho was discovered more than 50 years ago because of its ability to stop, or terminate, transcription. In every textbook, Rho is used as a model terminator that, using its very strong motor force, binds to the RNA and pulls it out of RNA polymerase. But a closer look by these scientists showed that Rho wouldn't be able to find the RNAs it needs to release using the textbook mechanism.

Researchers started studying Rho, and realized it cannot possibly work in ways people tell us it works!

The research determined that instead of attaching to a specific piece of RNA near the end of transcription and helping it unwind from DNA, Rho actually "hitchhikes" on RNA polymerase for the duration of transcription. Rho cooperates with other proteins to eventually coax the enzyme through a series of structural changes that end with an inactive state enabling release of the RNA.

The team used sophisticated microscopes to reveal how Rho acts on a complete transcription complex composed of RNA polymerase and two accessory proteins that travel with it throughout transcription.

It answers a fundamental question—transcription is fundamental to life, but if it were not controlled, nothing would work. RNA polymerase by itself has to be completely neutral. It has to be able to make any RNA, including those that are damaged or could harm the cell. While traveling with RNA polymerase, Rho can tell if the synthesized RNA is worth making—and if not, Rho releases it.

"Steps toward translocation-independent RNA polymerase inactivation by terminator ATPase ρ" Science (2020). science.sciencemag.org/lookup/ … 1126/science.abd1673

https://phys.org/news/2020-11-revealing-secret-key-cellular-refutes...

Scientists develop new gene therapy for eye disease

Scientists  have developed a new gene therapy approach that offers promise for one day treating an eye disease that leads to a progressive loss of vision and affects thousands of people across the globe.

The study also has implications for a much wider suite of neurological disorders associated with aging.

Characterized by degeneration of the optic nerves, DOA typically starts to cause symptoms in patients in their early adult years. These include moderate vision loss and some color vision defects, but severity varies, symptoms can worsen over time and some people may become blind. There is currently no way to prevent or cure DOA.

A gene (OPA1) provides instructions for making a protein that is found in cells and tissues throughout the body, and which is pivotal for maintaining proper function in mitochondria, which are the energy producers in cells.

Without the protein made by OPA1, mitochondrial function is sub-optimal and the mitochondrial network which in healthy cells is well interconnected is highly disrupted.

For those living with DOA, it is mutations in OPA1 and the dysfunctional mitochondria that are responsible for the onset and progression of the disorder. 

The scientists, led by Dr. Daniel Maloney and Professor Jane Farrar from Trinity's School of Genetics and Microbiology, have developed a new gene therapy, which successfully protected the visual function of mice who were treated with a chemical targeting the mitochondria and were consequently living with dysfunctional mitochondria.

The scientists also found that their gene therapy improved mitochondrial performance in human cells that contained mutations in the OPA1 gene, offering hope that it may be effective in people.

They used a clever lab technique that allows scientists to provide a specific gene to cells that need it using specially engineered non-harmful viruses. This allowed them to directly alter the functioning of the mitochondria in the cells theytreated, boosting their ability to produce energy which in turn helps protects them from cell damage.

These results  demonstrate that this OPA1-based gene therapy can potentially provide benefit for diseases like DOA, which are due to OPA1 mutations, and also possibly for a wider array of diseases involving mitochondrial dysfunction

https://www.frontiersin.org/articles/10.3389/fnins.2020.571479/full

https://www.tcd.ie/news_events/articles/scientists-develop-new-gene...

https://medicalxpress.com/news/2020-11-scientists-gene-therapy-eye-...

Study is the first to link microbiota to dynamics of the human immune system

Researchers have uncovered an important finding about the relationship between the microbiota and the immune system, showing for the first time that the concentration of different types of immune cells in the blood changes in relation to the presence of different bacterial strains in the gut.

In recent years, the microbiota—the community of bacteria and other microorganisms that live on and in the human body—has captured the attention of scientists and the public, in part because it's become easier to study. It has been linked to many aspects of human health.

A multidisciplinary team from Memorial Sloan Kettering has shown for the first time that the gut microbiota directly shapes the makeup of the human immune system. Specifically, their research demonstrated that the concentration of different types of immune cells in the blood changed in relation to the presence of different bacterial strains in the gut. The results of their study, which used more than ten years of data collected from more than 2,000 patients, is being published November 25, 2020, in Nature.

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The data that were used in the study came from people receiving allogeneic stem cell and bone marrow transplants (BMTs). After strong chemotherapy or radiation therapy is used to destroy cancerous blood cells, the patient's blood-forming system is replaced with stem cells from a donor. For the first few weeks until the donor's blood cells—including the white blood cells that make up the immune system—have established themselves, the patients are extremely vulnerable to infections. To protect them during this time, patients are given antibiotics.

But many of these antibiotics have the unwanted side effect of destroying healthy microbiota that live in the gut, allowing dangerous strains to take over. When the patient's immune system has reconstituted, the antibiotics are discontinued, and the gut microbiota slowly starts to grow back.

The parallel recoveries of the immune system and the microbiota, both of which are damaged and then restored, gives us a unique opportunity to analyze the associations between these two systems.

Jonas Schluter et al. The gut microbiota is associated with immune cell dynamics in humans, Nature (2020). DOI: 10.1038/s41586-020-2971-8

https://medicalxpress.com/news/2020-11-link-microbiota-dynamics-hum...

Foreign vs. own DNA: How an innate immune sensor tells friend from foe

How do molecules involved in activating our immune system discriminate between our own DNA and foreign pathogens? Researchers deciphered the structural and functional basis of a DNA-sensing molecule when it comes in contact with the cell's own DNA, providing crucial insights into the recognition of self vs. non-self DNA.

DNA within our cells is compacted and stored in the nucleus in the form of chromatin (DNA wraped around histone proteins, forming nucleosomes, the basic unit of chromatin). DNA found outside the nucleus, in the cytoplasm, is an important signal that triggers immune responses indicating the presence of an intracellular pathogen or a potentially cancerous cell. DNA sensing is carried out by cGAS, an enzyme responsible for recognizing and binding naked DNA. When activated, cGAS synthesizes cyclic GMP-AMP, which in turn initiates the body's so-called "innate" immune system—the first-line-of-defense part of our immune system.

Until now, cGAS was thought to function predominantly in the cytoplasm, detecting foreign, non-self, DNA such as viruses. But recent studies suggested that cGAS is also present inside the nucleus. This was puzzling given the possibility that the enzyme is activated by its own DNA triggering an unwanted inflammatory response against its own DNA. Intrigued by this observation, researchers used structural biology as a discovery tool and found that cGAS is present in the nucleus in an inactive state. They teamed up with the Ablasser lab at the EPFL to decipher the mechanism of cGAS inactivation by chromatin in cells.

Taking advantage of  cryo-electron microscopy (cryo-EM), the researchers derived the structure of cGAS bound to a nucleosome. They found that cGAS directly engages the histone proteins of nucleosomes. Once bound to the nucleosome, cGAS is "trapped" in a state in which it is unable to engage or sense naked DNA. It is then also unable to synthesize GMP-AMP and remains inactivated. cGAS, when present in the nucleus of healthy cells, is thus inactivated by chromatin, and does not participate in innate immune signaling in response to its own DNA.

 Ganesh R. Pathare et al. Structural mechanism of cGAS inhibition by the nucleosome, Nature (2020). DOI: 10.1038/s41586-020-2750-6

https://phys.org/news/2020-11-foreign-dna-innate-immune-sensor.html...

Ancient Earth had a thick, toxic atmosphere like Venus—until it cooled off and became liveable

A rocky planet like Earth is born through a process called "accretion", in which initially small particles clump together under the pull of gravity to form larger and larger bodies. The smaller bodies, called "planetesimals", look like asteroids, and the next size up are "planetary embryos". There may have been many planetary embryos in the early Solar System, but the only one that still survives is Mars, which is not a fully fledged planet like Earth or Venus.

The late stages of accretion involve giant impacts that release enormous amounts of energy. We think the last impact in Earth's accretion involved a Mars-sized embryo hitting the growing Earth, spinning off our Moon, and melting most or all of what was left.

The impact would have left Earth covered in a global sea of molten rock called a "magma ocean". The magma ocean would have leaked hydrogen, carbon, oxygen and nitrogen gases, to form Earth's first atmosphere.

This ratio of CO₂ to N₂ is strikingly like the present atmosphere on Venus. So why did Venus, but not Earth, retain the hellishly hot and toxic environment we observe today?

The answer is that Venus was too close to the Sun. It simply never cooled down enough to form water oceans. Instead, the H₂O in the atmosphere stayed as water vapour and was slowly but inexorably lost to space.

On the early Earth, the water oceans instead slowly but steadily drew down CO₂ from the atmosphere by reaction with rock – a reaction known to science for the past 70 years as the “Urey reaction”, after the Nobel prizewinner who discovered it – and reducing atmospheric pressure to what we observe today.

So, although both planets started out almost identically, it is their different distances from the Sun that put them on divergent paths. Earth became more conducive to life while Venus became increasingly inhospitable.

Paolo A. Sossi et al. Redox state of Earth's magma ocean and its Venus-like early atmosphere, Science Advances (2020). DOI: 10.1126/sciadv.abd1387

https://theconversation.com/ancient-earth-had-a-thick-toxic-atmosph...

New Hubble data explains missing dark matter

New data from the NASA/ESA Hubble Space Telescope provides further evidence for tidal disruption in the galaxy NGC 1052-DF4. This result explains a previous finding that this galaxy is missing most of its dark matter. By studying the galaxy's light and globular cluster distribution, astronomers have concluded that the gravity forces of the neighbouring galaxy NGC 1035 stripped the dark matter from NGC 1052-DF4 and are now tearing the galaxy apart.

The galaxy "missing dark matter" NGC1052-DF4 is undergoing tidal disruption arXiv:2010.09719 [astro-ph.GA] arxiv.org/abs/2010.09719

https://phys.org/news/2020-11-hubble-dark.html?utm_source=nwletter&...

High blood pressure in midlife is linked to increased brain damage in later life

Higher than normal blood pressure is linked to more extensive brain damage in the elderly, according to a new study published.

In particular, the study found that there was a strong association between diastolic blood pressure (the blood pressure between heart beats) before the age of 50 and brain damage in later life, even if the diastolic blood pressure was within what is normally considered to be a healthy range.

The findings come from a study of 37,041 participants enrolled in UK Biobank, a large group of people recruited from the general population aged between 40 and 69 years, and for whom medical information, including MRI brain scans was available.

Karolina Agnieszka Wartolowska et al, Midlife blood pressure is associated with the severity of white matter hyperintensities: analysis of the UK Biobank cohort study, European Heart Journal (2020). DOI: 10.1093/eurheartj/ehaa756

https://medicalxpress.com/news/2020-11-high-blood-pressure-midlife-...

**Climate change is making autumn leaves change colour earlier – here’s why

research shows that deciduous trees can only absorb a set amount of carbon each year and once that limit is reached, no more can be absorbed. At that point, leaves begin to change colour. This limit is set by the availability of nutrients, particularly nitrogen, and the physical structure of the plant itself, particularly the inner vessels which move water and dissolved nutrients around. Nitrogen is a key nutrient which plants need in order to grow, and it’s often the amount of available nitrogen that limits total growth. This is why farmers and gardeners use nitrogen fertilisers, to overcome this limitation.

Together, these constraints mean that carbon uptake during the growing season is a self-regulating mechanism in trees and herbaceous plants. Only so much carbon can be taken up.

In a world with increasing levels of carbon in the atmosphere, these new findings imply that warmer weather and longer growing seasons will not allow temperate deciduous trees to take up more carbon dioxide. The study’s predictive model suggests that by 2100, when tree growing seasons are expected to be between 22 and 34 days longer, leaves will fall from trees between three and six days earlier than they do now.

with the prospect of some trees losing their leaves earlier and others losing them at the time they do now, there might be the prospect of prolonged autumnal colours – and more time for us to kick through the leaves.

https://theconversation.com/climate-change-is-making-autumn-leaves-...

https://researchnews.cc/news/3819/Which-factors-trigger-leaf-die-of...

Moth wings sport acoustic camouflage

Moths draped in stealth acoustic cloak evade bat sonar

Moths can hide from the sonar of feeding bats using their acoustically camouflaged wings. Their evolved stealth adaptation is the result of an array of scales attached to their wing membranes that absorb ultrasound frequencies emitted by hunting bats, and are the first acoustic metamaterials found in nature.

A University of Bristol team discovered that sound waves from bats that hit the fork-shaped scales found on two species of moth cause them to bend and twist, dissipating the energy. ‘Less sound is reflected back to the bat, and the moth thereby disappears or partially disappears from the bat’s sonar screen

Z Shen et al, Proc. Natl. Acad. Sci. USA, 2018, 115, 12200 (DOI: 10.1073/pnas.1810025115)

https://www.chemistryworld.com/news/moths-draped-in-stealth-acousti...

Scales on the wings of moths form acoustic camouflage that hides the insects from the sonar of bats. Researchers examined the Chinese tusar moth (Antheraea pernyi) and Dactyloceras lucina, a large African moth. These species have no ears to hear approaching predators. Instead, they defend themselves using a dense array of tiny, thin scales that each resonate at a particular frequency. Together, the scales absorb at least three octaves of sound — the first known natural acoustic metamaterial. The intricate arrangement and structure of the scales could inspire ultrathin sound-absorbing materials: think sound-absorbing wallpaper instead of panels, say researchers.

**   Pregnancy stress may shape baby brain

Stress levels in mothers – measured by a hormone linked to anxiety and other health problems – is related to changes in areas of the infant brain associated with emotional development, the study suggests. Doctors say the findings highlight the urgent need for women to be better supported with their mental and physical health before and during pregnancy, and could help them spot mums and babies who need help. The experts add that pregnant women who feel stressed or unwell should seek help from their midwife or consultant and that with support, most health issues can be well managed in pregnancy. Maternal stress is known to influence the development of the child’s behaviour and ability to regulate its emotions as it grows. This is usually measured by questionnaires, which are not always reliable. The new study is the first time that scientists have used an objective measure – levels of the hormone cortisol – in the mother to study links with baby brain development.

https://researchnews.cc/news/3791/Pregnancy-stress-may-shape-baby-b...

Miniscule robots of metal and plastic

Understanding Skull Base Tumors

https://www.uhhospitals.org/health-information/health-and-wellness-....

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Periodic table: scientists propose new way of ordering the elements

https://theconversation.com/periodic-table-scientists-propose-new-w...

Immune responses during embryo development could increase risk of schizophrenia

 Research has often highlighted the effects that immune activation in pregnant women can have on the development of human embryos, for instance increasing the risk of a child developing psychiatric disorders later in life. The neural mechanisms underpinning these effects, however, remained largely unclear till now.

Researchers  have recently carried out a study investigating the impact that the activation of microglia (i.e., a specialized cell population that removes damaged neurons or infections) can have on an embryo's development of a specific class of neurons that regulates information processing, known as cortical interneurons. Their findings, published in Nature Neuroscience, suggest that activated microglia can cause metabolic disruptions that adversely impact the development of cortical interneurons. Interestingly, in individuals diagnosed with schizophrenia these disruptions could persist when the microglia are no longer activated.

They found found that the metabolism of cortical interneurons is compromised under inflammatory condition during development, which showed prolonged impact in cortical interneurons derived from schizophrenia iPSCs but not healthy control iPSCs. These findings highlight the existence of interactions between schizophrenia genetic backgrounds and environmental risk factors.

Activated microglia cause metabolic disruptions in developmental cortical interneurons that persist in interneurons from individuals with schizophrenia. Nature Neuroscience(2020). DOI: 10.1038/s41593-020-00724-1

https://medicalxpress.com/news/2020-11-immune-responses-embryo-schi...

Gut microbes: The key to normal sleep

A detailed study in mice revealed the extent to which bacteria can change the environment and contents of the intestines, which ultimately impacts behaviours like sleep.

Researchers gave a group of mice a powerful cocktail of antibiotics for four weeks, which depleted them of intestinal microorganisms. Then, they compared intestinal contents between these mice and control mice who had the same diet.

Digestion breaks food down into bits and pieces called metabolites. The researchers found significant differences between metabolites in the microbiota-depleted mice and the control mice. They found more than 200 metabolite differences between mouse groups. About 60 normal metabolites were missing in the microbiota-depleted mice, and the others differed in the amount, some more and some less than in the control mice.

The team next set out to determine what these metabolites normally do. Using metabolome set enrichment analysis, they found that the biological pathways most affected by the antibiotic treatment were those involved in making neurotransmitters, the molecules that cells in the brain use to communicate with each other. For example, the tryptophan–serotonin pathway was almost totally shut down; the microbiota-depleted mice had more tryptophan than controls, but almost zero serotonin. This shows that without important gut microbes, the mice could not make any serotonin from the tryptophan they were eating. The team also found that the mice were deficient in vitamin B6 metabolites, which accelerate production of the neurotransmitters serotonin and dopamine. The team also analyzed how the mice slept by looking at brain activity in EEGs. They found that compared with the control mice, the microbiota-depleted mice had more REM and non-REM sleep at night—when mice are supposed to be active—and less non-REM sleep during the day—when mice should be mostly sleeping. The number of REM sleep episodes was higher both during the day and at night, whereas the number of non-REM episodes was higher during the day. In other words, the microbiota-depleted mice switched between sleep/wake stages more frequently than the controls.

So blame your gut microbes if you can't sleep properly and thank them if you can!

Yukino Ogawa et al. Gut microbiota depletion by chronic antibiotic treatment alters the sleep/wake architecture and sleep EEG power spectra in mice, Scientific Reports (2020). DOI: 10.1038/s41598-020-76562-9

https://medicalxpress.com/news/2020-11-gut-microbes-key.html?utm_so...

Physicists invent printable superconducting device

Superconducting devices such as SQUIDS (Superconducting Quantum Interferometry Device) can perform ultra-sensitive measurements of magnetic fields. Leiden physicsts invented a method to 3-D-print these and other superconducting devices in minutes.

How to Print a Quantum Device in Less than 30 Minutes