This work investigated the patterns of disturbed blood flow in two different model carotids, one with high risk geometrical factors and the other without.

 high-risk factors include high flare and low proximal curvature in the sinus. Flare is defined as the ratio of the maximum cross section in the sinus bulb to its minimal value, while proximal curvature measures how much the artery curves above the bifurcation point.

To model exercise, the authors digitized blood flow measurements from individuals in three different age groups: 32-34, 54-55, and 62-63. These digitized flowrates were used as input to their computational model.

"Overall, the effects of exercise are different for different people. Particularly, we show that exercising decreases the reversed flow volume for the 62-63 age group with the low-risk carotid, which is probably related to the decrease of systolic time interval.

This suggests that evaluating the effect of exercise on atherosclerosis requires consideration of patient-specific geometries and ages.

"Effects of exercise on flow characteristics in human carotids" Physics of Fluids (2022). aip.scitation.org/doi/full/10.1063/5.0078061

https://phys.org/news/2022-01-simulation-age-effects-plaque-formati...

Part 2

**

Applying ice to a severe muscle injury may prolong the recovery process, researchers from Japan have found.

A pack of ice is often regarded as one’s best weapon against a muscle injury. But new research from Japan suggests otherwise, revealing that applying ice might actually prolong the recovery time. The findings were published in the Journal of Applied Physiology.

Whether you are a professional athlete or a casual gym-goer, skeletal muscle injuries are quite common. To soothe the injuries, coaches and physiotherapists have long been advising the application of ice. The logic being that icing helps in reducing inflammation. However, little has been established about the long-term effects of this widely practiced intervention, especially for severe injuries.

Our bodies respond to the muscle injuries through inflammation, which is a critical process helping regeneration of the destroyed tissue. Given that icing suppresses the inflammation, it might be derailing the self-repair mechanisms for severe muscle damage even if the coolness may soothe the pain early on. There have been inconsistent scientific data on whether or not icing helps in tissue repair. The answer may lie in how severe is the injury.

To advance the debate, researchers led by Associate Professor Takamitsu Arakawa from Kobe University in Japan investigated post-injury icing on a cellular level. A mouse model was used to mimic common sports injuries, where the muscles lengthen due to overexertion of force beyond the body’s current capacity—effectively tearing the muscle tissue.

The team immediately applied ice on the mice leg muscles. Then it examined the extent of muscle recovery two weeks later. For comparison, the researchers injured another set of mice but didn’t apply any ice. The non-iced group showed a significantly greater number of medium to large muscle fibers, while the iced group had mostly regenerated small muscle fibers, suggesting that icing delayed recovery of severe injuries.

According to the researchers, immune cells called pro-inflammatory macrophages may be involved in the repair mechanisms. They infiltrate the injured muscle tissue and remove damaged cells, which results in inflammation. This, in turn, spurs anti-inflammatory macrophages to swarm the injury site, suppressing inflammation and jumpstarting the building of new muscle cells.

That means the inflammation itself is key to the recovery of damaged tissues. Applying ice, however, seems to dampen this inflammatory response. The team speculated that icing may have deterred the arrival of the pro-inflammatory macrophages and consequently delayed the formation of new muscle tissue.

While skipping the ice step could speed up recovery for severe injuries, mild muscle damage might still benefit from the chilly interventions. The next step is to work out where to draw the line between mild and severe injuries, the researchers noted.

https://journals.physiology.org/doi/abs/10.1152/japplphysiol.01069....

 Kawashima et al. (2021) Icing After Eccentric Contraction-induced M...

https://www.asianscientist.com/2022/01/in-the-lab/icing-muscle-inju...

New study suggests two paths toward 'super immunity' to COVID-19

New laboratory research from Oregon Health & Science University reveals more than one path toward robust immunity from COVID-19.

A new study finds that two forms of immunity—breakthrough infections following vaccination or natural infection followed by vaccination—provide roughly equal levels of enhanced immune protection.

The new study was published in the journal Science Immunology.

It makes no difference whether you get infected-and-then-vaccinated, or if you get vaccinated-and-then-a-breakthrough infection. In either case, you will get a really, really robust immune response—amazingly high.

The research follows an OHSU study published in December that described extremely high levels of immune response following breakthrough infections—so-called "super immunity." That study was the first to use multiple live SARS-CoV-2 variants to measure cross-neutralization of blood serum from breakthrough cases.

The new study found that it doesn't matter whether someone gets a breakthrough infection or gets vaccinated after a natural infection. In both cases, the immune response measured in blood serum revealed antibodies that were equally more abundant and more potent—at least 10 times more potent—than immunity generated by vaccination alone.

The study was done before the emergence of the omicron variant, but researchers expect the hybrid immune responses would be similar with the new highly transmissible variant.

The likelihood of getting breakthrough infections is high because there is so much virus around us right now. But we position ourselves better by getting vaccinated. And if the virus comes, we'll get a milder case and end up with this super immunity.

Part 1

Researchers recruited a total of 104 people, all OHSU employees who were vaccinated by the Pfizer vaccine, and then carefully divided them into three groups: 42 who were vaccinated with no infection, 31 who were vaccinated after an infection, and 31 who had breakthrough infections following vaccination. Controlling for age, sex and time from vaccination and infection, the researchers drew blood samples from each participant and exposed the samples to three variants of the live SARS-CoV-2 virus in a Biosafety Level 3 lab . 

They found both of the groups with "hybrid immunity" generated greater levels of immunity compared with the group that was vaccinated with no infection.

1. Timothy A. Bates, Savannah K. McBride, Hans C. Leier, Gaelen Guzman, Zoe L. Lyski, Devin Schoen, Bradie Winders, Joon-Yong Lee, David Xthona Lee, William B. Messer, Marcel E. Curlin, Fikadu G. Tafesse. Vaccination before or after SARS-CoV-2 infection leads to robust humoral response and antibodies that effectively neutralize variants. Science Immunology, 2022; DOI: 10.1126/sciimmunol.abn8014
2. Timothy A. Bates, Savannah K. McBride, Bradie Winders, Devin Schoen, Lydie Trautmann, Marcel E. Curlin, Fikadu G. Tafesse. Antibody Response and Variant Cross-Neutralization After SARS-CoV-2 Breakthrough Infection. JAMA, 2022; 327 (2): 179 DOI: 10.1001/jama.2021.22898

https://researchnews.cc/news/11272/New-study-suggests-two-paths-tow...

Part 2

Researchers regrow frog's lost leg

For millions of patients who have lost limbs for reasons ranging from diabetes to trauma, the possibility of regaining function through natural regeneration remains out of reach. Regrowth of legs and arms remains the province of salamanders and superheroes.

But in a study published in the journal Science Advances, scientists at Tufts University and Harvard University's Wyss Institute have brought us a step closer to the goal of regenerative medicine.

On adult frogs, which are naturally unable to regenerate limbs, the researchers were able to trigger regrowth of a lost leg using a five-drug cocktail applied in a silicone wearable bioreactor dome that seals in the elixir over the stump for just 24 hours. That brief treatment sets in motion an 18-month period of regrowth that restores a functional leg.

Many creatures have the capability of full regeneration of at least some limbs, including salamanders, starfish, crabs, and lizards. Flatworms can even be cut up into pieces, with each piece reconstructing an entire organism. Humans are capable of closing wounds with new tissue growth, and our livers have a remarkable, almost flatworm-like capability of regenerating to full size after a 50% loss.

But loss of a large and structurally complex limb—an arm or leg—cannot be restored by any natural process of regeneration in humans or mammals. In fact, we tend to cover major injuries with an amorphous mass of scar tissue, protecting it from further blood loss and infection and preventing further growth.

researchers triggered the regenerative process in African clawed frogs by enclosing the wound in a silicone cap, which they call a BioDome, containing a silk protein gel loaded with the five-drug cocktail.

Each drug fulfilled a different purpose, including tamping down inflammation, inhibiting the production of collagen which would lead to scarring, and encouraging the new growth of nerve fibers, blood vessels, and muscle. The combination and the bioreactor provided a local environment and signals that tipped the scales away from the natural tendency to close off the stump, and toward the regenerative process.

The researchers observed dramatic growth of tissue in many of the treated frogs, re-creating an almost fully functional leg. The new limbs had bone structure extended with features similar to a natural limb's bone structure, a richer complement of internal tissues (including neurons), and several "toes" grew from the end of the limb, although without the support of underlying bone.

The regrown limb moved and responded to stimuli such as a touch from a stiff fiber, and the frogs were able to make use of it for swimming through water, moving much like a normal frog would.

Part 1

Animals naturally capable of regeneration live mostly in an aquatic environment. The first stage of growth after loss of a limb is the formation of a mass of stem cells at the end of the stump called a blastema, which is used to gradually reconstruct the lost body part. The wound is rapidly covered by skin cells within the first 24 hours after the injury, protecting the reconstructing tissue underneath.

"Mammals and other regenerating animals will usually have their injuries exposed to air or making contact with the ground, and they can take days to weeks to close up with scar tissue.

Using the BioDome cap in the first 24 hours helps mimic an amniotic-like environment which, along with the right drugs, allows the rebuilding process to proceed without the interference of scar tissue."

Nirosha J. Murugan et al, Acute multidrug delivery via a wearable bioreactor facilitates long-term limb regeneration and functional recovery in adult Xenopus laevis, Science Advances (2022). DOI: 10.1126/sciadv.abj2164. www.science.org/doi/10.1126/sciadv.abj2164

https://medicalxpress.com/news/2022-01-regrow-frog-lost-leg.html?ut...

Are There Oceans on Other Worlds?

New hair dyes avoid allergic reactions

A bad dye job is bad enough on its own, but an itchy and irritating allergic reaction to it is even worse. And people who become allergic to hair dye can develop reactions to many other common substances, transforming a simple cosmetic treatment into a big problem. Now, researchers reporting in ACS Sustainable Chemistry & Engineering have developed a range of permanent hair dyes that avoid the allergenic properties of traditional formulations.

When applied as hair color, paraphenylenediamine (PPD)—a common ingredient in permanent dyes—undergoes a chemical reaction that turns the hair a dark color that won't wash out over time. This reaction, however, can also produce compounds that bind proteins in the user's skin, causing allergic responses, such as eczema and facial swelling. PPD can also sensitize users to other substances, including a compound commonly found in sunscreens and cosmetics, as well as common pigment and ink compounds. Alternatives have been proposed, but they generally are not water-soluble, and the safety of some of the compounds are not well understood. Researchers wanted to create new alternatives that would avoid the problems of PPD while still providing permanent hair coloring.

The team prepared seven dyes based on PPD with modifications to the aromatic amine core. The modifications were chosen to potentially make the compounds less reactive toward proteins and less able to be absorbed into skin. All seven compounds permanently colored hair samples, producing a range of hues from rosy pinks to deep blacks that did not fade, even after three weeks of daily washing. The team then examined the dyes in a test commonly used in the cosmetics industry to determine if a product is a skin sensitizer. Five of the modified dyes were "weak" sensitizers, whereas PPD was "moderate." Another test showed that the new compounds generated a reduced inflammatory response in cells compared to PPD. These results suggest that the new dyes can effectively color hair while also avoiding the potential allergenic and sensitization risks of more traditional ones.

opalakrishnan Venkatesan et al, Synthesis and Assessment of Non-allergenic Aromatic Amine Hair Dyes as Efficient Alternatives to Paraphenylenediamine, ACS Sustainable Chemistry & Engineering (2022). DOI: 10.1021/acssuschemeng.1c06313

https://phys.org/news/2022-01-hair-dyes-allergic-reactions.html?utm...

Bacteria build communities using chemical signals comparable to radio waves

What wintering squirrels can teach astronauts

When bears and ground squirrels hibernate in winter, they stop eating, lasting until spring simply on the fat reserves they've stored up in their bodies. Usually, this sort of prolonged fasting and inactivity would significantly reduce the mass and function of muscle, but hibernators don't suffer this fate. How they avoid it, however, has been a mystery.

Now, in research published in Science,  biologists have figured out why, and their findings could have implications for, of all things, the future of space travel . By studying a variety called the 13-lined ground squirrel that is common in North America, researchers have confirmed a theory known as "urea nitrogen salvage" dating back to the 1980s.

The theory posits that hibernators harness a metabolic trick of their gut microbes to recycle the nitrogen present in urea, a waste compound that is usually excreted as urine, and use it to build new tissue proteins.

How could this discovery be of use in space? Theoretically by helping astronauts minimize their own muscle-loss problems caused by microgravity-induced suppression of protein synthesis and which they now try to reduce by intensively exercising.

If a way could be found to augment the astronauts' muscle protein synthesis processes using urea nitrogen salvage, they could be able to achieve better muscle health during long voyages into deep space in spacecraft too small for the usual exercise equipment, the argument goes.

Matthew D. Regan et al, Urea nitrogen recycling via gut symbionts increases in hibernating ground squirrels over the winter, Science (2022). DOI: 10.1126/science.abh2950. www.science.org/doi/10.1126/science.abh2950

https://phys.org/news/2022-01-wintering-squirrels-astronauts.html?u...

How do algae survive excess oxygen?

Pulse oximeter measurements of blood oxygen levels are unreliable in assessing severity of Covid-19 pneumonia

The severity of Covid-19 pneumonia can be difficult to assess in people from different ethnic groups, due to inaccurate readings from a device that measures the level of oxygen in the blood of patients.

The findings of the research, published in the European Respiratory Journal, show that pulse oximeters gave false readings of nearly 7% higher in a group of patients of Mixed ethnicity with Covid-19, compared to White patients at just over 3%. There were also falsely high readings in patients with both Black and Asian ethnicity, which could delay patients receiving the best and most timely treatment for the virus.

Pulse oximetry is a non-invasive test that measures the oxygen saturation level of the blood. It can rapidly detect even small changes in oxygen levels. These levels show how efficiently blood is carrying oxygen to the extremities furthest from the heart, including the arms and legs. Medical professionals routinely use them in primary care and critical care settings like emergency rooms or hospitals to monitor the clinical status of their patients.

The light wave transmission that this technology uses is modified by skin pigmentation and may vary by skin colour. A recent study reported different outputs in patients with Black skin compared to patients with White skin, which has the potential to adversely affect patient care. This led to the Food and Drink Administration in the USA releasing an expression of concern about the accuracy of pulse oximeters in 2021, which led to the current study.

Researchers  made use of the electronic datasets that are collected for clinical use in real time, but archived and available to answer important clinical questions and improve both patient care and patient safety in the future. The NUH Covid-19 Patient Safety Database is anonymised to allow lessons to be learned without compromising individual patient confidentiality. The team included clinicians, managers, statisticians, computer analysts, software coders and data warehouse archivists.

The team of experts from Nottingham used data from patients with Covid-19 infection to look at the difference in blood oxygen levels as measured by pulse oximetry and arterial blood gas tests, spilt into different ethnic groups over a wide range of oxygen saturations. Arterial blood gas tests measure the levels of oxygen in the blood from an artery, and represent the gold standard measurement for oxygen levels.

Part1

The team used electronic data for patients admitted to Nottingham University Hospitals NHS Trust between February 2020 and September 2021 with Covid-19 infection. Pulse oximetry measurements with a paired blood gas measurement within a half an hour window were compared.

Mean differences between pulse oximetry and blood gas oxygen saturations were recorded by ethnicity of White, Mixed, Asian, and Black patients, and were also split up by level of oxygen saturation as measured by arterial blood gases.

There were differences in oxygen saturations (amounts of oxygen in the blood), between the pulse oximetry arterial blood gas readings in all groups. The highest difference was in the Mixed ethnicity group which was nearly 7% higher in the oximetry reading, with the lowest in the White group at 3.2% higher than the true measurement from arterial blood gases. A reading of 5.4% higher using pulse oximetry was found in the Black group of participants and 5.1% higher in the Asian population.

The difference between the readings also increased in the clinically important range of 85 to 89%, when many clinical decisions are made. Mean values as measured by pulse oximeter were higher than reality in individuals with a recorded Black and Asian ethnicity, compared to those of a White ethnicity.

The findings of the research are important as high levels of skin pigmentation are associated with ethnic groups who have a poorer outcome from Covid-19 infection, and would require the most accurate oxygen measurements available in order to deliver the most appropriate and timely treatment.

1. Colin J Crooks, Joe West, Joanne R Morling, Mark Simmonds, Irene Juurlink, Steve Briggs, Simon Cruickshank, Susan Hammond-Pears, Dominick Shaw, Timothy R Card, Andrew W Fogarty. Pulse oximeters' measurements vary across ethnic groups: An observational study in patients with Covid-19 infection. European Respiratory Journal, 2022; 2103246 DOI: 10.1183/13993003.03246-2021

https://researchnews.cc/news/11340/Pulse-oximeter-measurements-of-b...

Part 2

Morphological fingerprinting could help identify side effects and new bioactive compounds in drug discovery

Pharmaceutical researchers speak of a hit when they come across a promising substance with a desired effect in early drug discovery. Unfortunately, hits are rarely bull's-eyes, often showing undesirable side effects that not only complicate the search for new hits, but also the subsequent development into a drug. A new study  could now help to better identify one of the most frequently observed side effects already in early drug discovery, but also to find new bioactivities.

The most commonly used cancer drugs contain active substances that manipulate the cell's cytoskeleton by binding to microtubules. This can disrupt cell division as well as impair other essential processes, and leads to cell death. Such an effect is of course not desirable for other therapies. However, microtubules' surface has many deep binding pockets that makes them particularly susceptible to modulation by a wide variety of chemical substances with diverse chemical scaffolds.

In the search for and development of new active substances, the study of known side effects plays a crucial role, especially when one considers that about 13 years and more than one billion US dollars are needed to develop a new drug. Although there are already standardized test procedures (screens) for identifying undesirable side effects, they certainly do not cover all targets in cells, often do not correctly reflect the cellular context, or they allow targets to be overlooked, e.g. binding to tubulin. Thus, drug discovery is always biased to a certain extent.

Researchers now  used a new strategy to reliably detect side effects, such as the disruption of microtubules, at an early stage of the search for bioactive compounds. To do this, the researchers employed the so-called "cell painting" approach. Here, several functional areas of the cell are stained and then examined microscopically for changes after the addition of chemical substances. This enables recording hundreds of cellular parameters in a single morphological fingerprint. If one detects similarity of this fingerprint to those of known reference substances, conclusions about the effect of the unknown substance can be drawn. The value of this approach lies in the possibility of creating fingerprints for thousands of substances in a high-throughput process. This way, the researchers revealed that more than 1% of about 15,000 studied substances had a tubulin-modulating effect. Among them was also a large number of known reference substances for which an influence on tubulin was previously unknown.

Part 1

Reference substances play an essential role in the interpretation of a screen, so they should be carefully evaluated and tested. The compounds identified by the cell painting show a wide variety of chemical scaffolds and even small chemical modifications can have a dramatic impact on the tubulin-binding properties of a compound. This risk is ubiquitous, especially during the compound optimization phase, where existing atoms are exchanged or removed and new atoms are added in order to improve the pharmacological properties. Additional morphological profiling during the search for hits and their optimization could not only help unmask side effects such as tubulin modulation early on, but also identify desired and new bioactivities. Moreover, this approach could save time and money as it helps to early assess whether a promising substance has what it takes to become a useful compound or not.

Mohammad Akbarzadeh, Ilka Deipenwisch, Beate Schoelermann, Axel Pahl, Sonja Sievers, Slava Ziegler, Herbert Waldmann. Morphological profiling by means of the Cell Painting assay enables identification of tubulin-targeting compounds. Cell Chemical Biology, 2021; DOI: 10.1016/j.chembiol.2021.12.009

https://researchnews.cc/news/11353/Morphological-fingerprinting-cou...

Part 2

Scientists uncover how the shape of melting ice depends on water temperature

A team of mathematicians and physicists has discovered how ice formations are shaped by external forces, such as water temperature. Its newly published research may offer another means for gauging factors that cause ice to melt.

The shapes and patterning of ice are sensitive indicators of the environmental conditions at which it melted, allowing researchers to 'read' the shape to infer factors such as the ambient water temperature. This  helps to understand how melting induces unusual flow patterns that in turn affect melting, which is one of the many complexities affecting the ice on our planet.

The researchers studied, through a series of experiments, the melting of ice in water and, in particular, how the water temperature affects the eventual shapes and patterning of ice. To do so, they created ultra-pure ice, which is free of bubbles and other impurities. The team recorded the melting of ice submerged into water tanks in a "cold room," which is similar to a walk-in refrigerator whose temperature is controlled and varied.

They focused on the cold temperatures—0 to 10 degrees Celsius—at which ice in natural waters typically melts, and  found a surprising variety of shapes that formed. 

Specifically, at very cold temperatures—those under about 5 degrees C—the pieces take on the shape of a spike or "pinnacle" pointing downward—similar to an icicle, but perfectly smooth (with no ripples). For temperatures above approximately 7 degrees C, the same basic shape forms, but upside down—a spike pointing upward. For in between temperatures, the ice has wavy and rippled patterns melted into its surface. Similar patterns, called "scallops," are found on icebergs and other ice surfaces in nature.

These shape differences are due to changes in water flows, which are determined by their temperatures.

Part 1

Melting causes gradients in the temperature of the water near the ice, which causes the liquid at different places to have different densities. This generates flows due to gravity—with heavier liquid sinking and lighter fluid rising—and such flows along the surface lead to different rates of melting at different locations and thus changes in shape.

The strange bit of physics is that liquid water has a highly unusual dependence of density on temperature, in particular a maximum of density at about 4 degrees C. "This 'density anomaly' makes water unique in comparison to other fluids."

The research shows that this property is responsible for producing very different flows, depending on the precise value of the water temperature. The downward pinnacles at low temperatures are associated with upward flows, while the upward pinnacles have downward flows. The scalloped patterns form because upward flows very near the surface interact with downward flows further away, destabilizing into vortices that carve pits into the ice.

Scott Weady et al, Anomalous Convective Flows Carve Pinnacles and Scallops in Melting Ice, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.128.044502

https://phys.org/news/2022-01-scientists-uncover-ice-temperature.ht...

Part 2

A pill that releases RNA in the stomach could offer a new way to administer vaccines

Like most vaccines, RNA vaccines have to be injected, which can be an obstacle for people who fear needles. Now, a team of  researchers has developed a way to deliver RNA in a capsule that can be swallowed, which they hope could help make people more receptive to them.

In addition to making vaccines easier to tolerate, this approach could also be used to deliver other kinds of therapeutic RNA or DNA directly to the digestive tract, which could make it easier to treat gastrointestinal disorders such as ulcers.

Nucleic acids, in particular RNA, can be extremely sensitive to degradation particularly in the digestive tract. Overcoming this challenge opens up multiple approaches to therapy, including potential vaccination through the oral route.

In a new study, researchers showed that they could use the capsule they developed to deliver up to 150 micrograms of RNA—more than the amount used in mRNA COVID vaccines—in the stomach of pigs.

part 1

For several years, scientists have been developing novel ways to deliver drugs to the gastrointestinal tract. In 2019, the researchers designed a capsule that, after being swallowed, can place solid drugs, such as insulin, into the lining of the stomach.

The pill, about the size of a blueberry, has a high, steep dome inspired by the leopard tortoise. Just as the tortoise is able to right itself if it rolls onto its back, the capsule is able to orient itself so that its contents can be injected into the lining of the stomach.

In 2021, the researchers showed that they could use the capsule to deliver large molecules such as monoclonal antibodies in liquid form. Next, the researchers decided to try to use the capsule to deliver nucleic acids, which are also large molecules.

Nucleic acids are susceptible to degradation when they enter the body, so they need to be carried by protective particles. For this study, the  team used a new type of polymeric nanoparticle  they had recently developed.

These particles, which can deliver RNA with high efficiency, are made from a type of polymer called poly(beta-amino esters). The MIT team's previous work showed that branched versions of these polymers are more effective than linear polymers at protecting nucleic acids and getting them into cells. They also showed that using two of these polymers together is more effective than just one.

Part 2

To test the particles, the researchers first injected them into the stomachs of mice, without using the delivery capsule. The RNA that they delivered codes for a reporter protein that can be detected in tissue if cells successfully take up the RNA. The researchers found the reporter protein in the stomachs of the mice and also in the liver, suggesting that RNA had been taken up in other organs of the body and then carried to the liver, which filters the blood.

Next, the researchers freeze-dried the RNA-nanoparticle complexes and packaged them into their drug delivery capsules. Working with scientists at Novo Nordisk, they were able to load about 50 micrograms of mRNA per capsule, and delivered three capsules into the stomachs of pigs, for a total of 150 micrograms of mRNA. This is the more than the amount of mRNA in the COVID vaccines now in use, which have 30 to 100 micrograms of mRNA.

In the pig studies, the researchers found that the reporter protein was successfully produced by cells of the stomach, but they did not see it elsewhere in the body. In future work, they hope to increase RNA uptake in other organs by changing the composition of the nanoparticles or giving larger doses. However, it may also be possible to generate a strong immune response with delivery only to the stomach.

"There are many immune cells in the gastrointestinal tract, and stimulating the immune system of the gastrointestinal tract is a known way of creating an immune response.

 Giovanni Traverso, Oral mRNA delivery using capsule-mediated gastrointestinal tissue injections, Matter (2022). DOI: 10.1016/j.matt.2021.12.022. www.cell.com/matter/fulltext/S2590-2385(21)00680-9

https://medicalxpress.com/news/2022-01-pill-rna-stomach-vaccines.ht...

Part 3

**

How  Climate Change is Affecting Hibernation?

Missing ear bone helps bats to echolocate

Some bats have an anatomical quirk in their ears that could explain how they evolved to hunt in specialized ways, from sensing small fish to catching insects midflight. In 2015, researchers took 3D images of the inner ear of a bat skull but couldn’t find a feature shared by almost all mammals: a bony tube that connects the ear to the brain and encases nerve cells. A more thorough search revealed many more bat species in which this bony nerve channel was missing or poked with large holes. Researchers suspect the loss of this bony channel gave the bats new hearing capabilities because the nerves are less confined.

Key growth factor protects gut from inflammatory bowel disease

IBD, a disease category including ulcerative colitis and Crohn's disease, features chronic gut inflammation and many potential follow-on effects including arthritis and colorectal cancer.

 A growth factor protein produced by rare immune cells in the intestine can protect against the effects of inflammatory bowel disease (IBD), according to a new discovery. 

In their study, published in Nature Immunology, the researchers found that the growth factor, HB-EGF, is produced in response to gut inflammation by a set of immune-regulating cells called ILC3s. These immune cells reside in many organs including the intestines, though their numbers are known to be depleted in the inflamed intestines of IBD patients.

The researchers showed in experiments in mice that this growth factor can powerfully counter the harmful effects of a key driver of intestinal inflammation called TNF. In doing so, ILC3s protect gut-lining cells when they would otherwise die and cause a breach in the intestinal barrier. 

Lei Zhou, Wenqing Zhou, Ann M. Joseph, Coco Chu, Gregory G. Putzel, Beibei Fang, Fei Teng, Mengze Lyu, Hiroshi Yano, Katrin I. Andreasson, Eisuke Mekada, Gerard Eberl, Gregory F. Sonnenberg. Group 3 innate lymphoid cells produce the growth factor HB-EGF to protect the intestine from TNF-mediated inflammation. Nature Immunology, 2022; DOI: 10.1038/s41590-021-01110-0

https://researchnews.cc/news/11380/Key-growth-factor-protects-gut-f...

Quantum leap on film

 In order to better understand (and possibly control) fast chemical reactions, it is necessary to study the behaviour of electrons as precisely as possible – in both space and time. However, up to now, microscopy methods have delivered only either spatially or temporally sharp images. By cleverly combining established techniques of tunnelling microscopy and laser spectroscopy, a team of researchers has now overcome these obstacles. Using their atomic quantum microscope, they can make the movement of electrons in individual molecules visible.

It is essential not only for understanding biological processes (e.g. plant photosynthesis) to map the electron dynamics in molecules but also for many technical applications such as the development of solar cells or new types of electronic components. Until now, imaging methods have sometimes delivered images that are difficult to reproduce – or even contradictory. This is because they cannot map the fast electrons directly but rather must resort to techniques that can only reconstruct the behaviour of the electrons.

Although modern microscopy techniques offer almost unlimited possibilities, certain compromises must be made. For example, scanning tunnelling microscopy with a resolution of one tenth of a picometre (1 × 10−12 m) allows extremely sharp images of individual atoms to be taken. However, this is slow and cannot capture the electron dynamics in a material. On the other hand, optical methods with ultra-fast laser pulses can detect electron movements in the attosecond (1 × 10−18 of a second) range. However, they can provide only coarse, washed-out spatial images – far removed from the atomic resolution possible with scanning tunnelling microscopes. The typical electron dynamics and laser pulses are in the range of a few hundred attoseconds.

Part 1

To do this, the researchers had to couple tried and tested scanning tunnelling microscopy with state-of-the-art laser technology. In a scanning tunnelling microscope, a wafer-thin, atomically thin tip travels just above a conductive surface. Thanks to the quantum-physical tunnel effect, electrons can flow between the surface and the microscope tip – even if there is no direct contact. For example, a molecule on a surface can gradually be shaved off atom by atom.

The new microscopy technique uses laser pulses in order to modulate the tunnel current by selectively exciting the electrons in the material. “This must be done extremely quickly. Otherwise, thermal effects come into play and make the measurements impossible. 

Thanks to the rapid development of laser technology in recent years, researchers have now been able to generate precisely the right pulses. Two years ago, Garg and Kern demonstrated the function of such an atomic quantum microscope for the first time.

They have now been able to directly observe electron movement in molecules with this one-of-a-kind instrument. With the help of the ultra-short pulses, the electrons in the molecule can be excited to jump between the different orbitals. This was noticeable in the tunnel flow. The highlight of the new technique is being able to fire two minimally time-delayed pulses in quick succession at the molecule to be investigated with an exact time interval and scan it in the process. If this procedure is repeated several times and the time interval between the pulses varied, an image series that reproduces the behaviour of the electrons in this molecule with atomic accuracy is obtained. The fast laser pulses thus provide the information about the electron dynamics whilst the scanning tunnelling microscope precisely scans the molecule.

This allowed the researchers to directly map the dynamics of electrons in molecules – how they jump from one orbital to another – for the first time. This basic technology provides completely new possibilities for directly observing quantum mechanical processes such as charge transfer in individual molecules and thus better understanding them. It is still not possible to predict the possible areas of application for such a quantum microscope. Especially in charge transfer processes, which play a crucial role in many biophysical reactions as well as in solar cells and transistors, it could provide crucial new insights.

https://www.mpg.de/18173993/quantum-leap-electron-film

Scientists discover link between high blood pressure and diabetes

The long-standing enigma of why so many patients suffering with high blood pressure (known as hypertension) also have diabetes (high blood sugar) has finally been cracked by an international team of researchers.

The important new discovery has shown that a small protein cell glucagon-like peptide-1 (GLP-1) couples the body's control of blood sugar and blood pressure.

GLP-1 is released from the wall of the gut after eating and acts to stimulate insulin from the pancreas to control blood sugar levels. This was known but what has now been unearthed is that GLP-1 also stimulates a small sensory organ called the carotid body located in the neck. Locating the link required genetic profiling and multiple steps of validation. 

The research group used an unbiased, high-throughput genomics technique called RNA sequencing to read all the messages of the expressed genes in the carotid body in rats with and without high BP. This led to the finding that the receptor that senses GLP-1 is located in the carotid body, but less so in hypertensive rats.

The carotid body is the convergent point where GLP-1 acts to control both blood sugar and blood pressure simultaneously; this is coordinated by the nervous system which is instructed by the carotid body.

People with hypertension and/or diabetes are at high risk of life-threatening cardiovascular disease. Even when receiving medication, a large number of patients will remain at high risk. This is because most medications only treat symptoms and not causes of high blood pressure and high sugar.

It is known that blood pressure is notoriously difficult to control in patients with high blood sugar, so these findings are really important because by giving GLP-1 we might be able to reduce both sugar and pressure together, and these two factors are major contributors to cardiovascular risk.

GLP1R attenuates sympathetic response to high glucose via carotid body inhibition, Circulation Research (2022). DOI: 10.1161/CIRCRESAHA.121.319874

https://medicalxpress.com/news/2022-02-sweet-pressurescientists-lin...

WHO warns of COVID medical waste threat

The World Health Organization warned recently that the vast amount of waste produced in tackling the COVID-19 pandemic posed a threat to human and environmental health.

The tens of thousands of tonnes of extra medical waste had put a huge strain on healthcare waste management systems, the WHO said in a report.

The extra waste is "threatening human and environmental health and exposing a dire need to improve waste management practices", the UN health agency said.

As countries scrambled to get personal protective equipment (PPE) to cope with the crisis, less attention was paid to disposing of COVID-19 health care waste safely and sustainably, the WHO said.

The latest available data, from 2019, suggested that one in three healthcare facilities globally did not safely manage healthcare waste—and in the 46 least-developed countries, more than two in three facilities did not have a basic healthcare waste management service.

"This potentially exposes health workers to needle stick injuries, burns and pathogenic microorganisms, while also impacting communities living near poorly-managed landfills and waste disposal sites through contaminated air from burning waste, poor water quality or disease-carrying pests," the WHO said.

https://phys.org/news/2022-02-covid-medical-threat.html?utm_source=...

The Astounding Physics of N95 Masks

Flowers in The UK Are Blooming a Whole Month Earlier Than They Did in The 1980s

For centuries, British flowers have been blooming like clockwork. A few months into spring, sometime around May or June, the nation bursts into color.

Since the early 1980s, however, hundreds of plants have grown out of sync with the seasons, which means they're also unraveling from the complicated tapestry of interactions that keep ecosystems sustainably functioning.

When analyzing the first blooms of 406 plant species from 1753 to 2019, researchers found a clear and worrisome shift.

On average, flowers in the UK are blooming almost a whole month earlier than they were before 1986. In 2019, the first mean flowering date was as early as April 2.

Obviously, not all plants bloom at the same time. Herbs and trees are the first to flower, sometime in mid-April. While shrubs take about a month longer to open up.

The whole timeline, however, has been pushed forward as the climate changes.

Today, human-caused global warming is progressing at a rapid and unprecedented rate, and it's impacting the very function of Earth's ecosystems.

Something as dependable as the changing of the seasons is no longer so. 

Early spring warming in the UK appears to be changing the amount of rain that falls and the snow that melts, and both of these factors are important when it comes to a budding flower.

If temperatures continue to rise, the authors worry there will be a further shift in first flowering dates, possibly starting March or even earlier.

This transition could lead some plants, including crops, to bud far too early, causing them to freeze or suffer frost damage.

"We do not know whether adaptive evolution will allow populations to reach new [optimum flowering timing] rapidly enough to keep pace with climate change.

Researchers fear these changes will lead to agricultural losses and extend the allergy season. But it's not just humans that will be impacted.

"The timing of plant flowering can affect their pollination, especially when insect pollinators are themselves seasonal, and determine the timing of seed ripening and dispersal.

Part 1

Plant flowering also influences animals for which pollen, nectar, fruits and seeds are important resources… "

The effects of an early flowering season could therefore ripple through ecosystems, causing what scientists call ecological (or phenological) mismatch – when the lifecycles of species that have evolved together and depend on each other fall out of sync.

This can lead to disrupted migration patterns, species starvation, outbreaks of pests and disease, and even extinction.

England isn't the only nation that has to worry about its flowering season. Earlier spring temperatures are being recorded throughout the world, both in the northern hemisphere and the southern hemisphere.

Last year, in Japan, cherry blossoms bloomed the earliest they have in 1,200 years.

Even with just a few centuries of data, however, the result of our emissions is clear to see. Climate change is winding up our Spring clock, and we don't know if we can wind it back again.

https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2456

Part 2

Uranus And Neptune Aren't The Same Color. A New Study Could Finally Explain Why

Uranus and Neptune are the most twin-like of all the planets in the Solar System. They are almost the same size and mass, have similar compositions and structures, even similar rotation rates.

Which makes one glaring difference quite perplexing. Neptune is a fetching shade of azure, with visible swirling storms. Uranus is more of a featureless, delicate pale teal. If the two planets are so similar, whence the difference in their methane-based blues?

New research, uploaded to preprint server arXiv and awaiting peer review, claims to have found an answer. According to a team led by planetary physicist Patrick Irwin of the University of Oxford in the UK, an extended layer of haze dilutes the hue of Uranus, resulting in a paler orb compared to its more distant twin; fraternal, not identical.

Uranus and Neptune, according to our measurements of the two planets, are structured very similarly. A small, rocky core is surrounded by a mantle of water, ammonia, and methane ices; next, a gaseous atmosphere consisting primarily of hydrogen, helium and methane; and finally the upper atmosphere, including cloud tops. But that atmosphere isn't homogeneous; rather, it is thought to be layered, like every other atmosphere in the Solar System.

Researchers analyzed visible and near-infrared observations of the two planets to generate new models of the atmospheric layers. They managed to find models that replicate the observations very well, including the storms on Neptune and the paler shade of Uranus.

In their models, both planets have a layer of photochemical haze. This occurs when ultraviolet radiation from the Sun breaks down aerosol particles in the atmosphere, producing haze particles. It's a common process, seen on Venus, Earth, Saturn, Jupiter, dwarf planet Pluto, and moons Titan and Triton.

The researchers called this the Aerosol-2 layer, and on both planets it seems to be a source of the cloud seeds that condense into methane ice at the lower boundary and snows deeper into the atmosphere. And on Uranus, this layer seems to be twice as opaque as it is on Neptune – and this is why the two planets look different.

https://arxiv.org/abs/2201.04516

https://www.sciencealert.com/we-might-finally-know-why-uranus-and-n...

Almost No Coral Reefs in The World Will Be Safe at 1.5°C Warming, Scientists Warn

Coral reefs have long been regarded as one of the earliest and most significant ecological casualties of global warming.

In new research published in the journal PLOS Climate, we found that the future of these tropical ecosystems – thought to harbor more species than any other – is probably worse than anticipated.

Climate change is causing more frequent marine heatwaves worldwide. Corals have adapted to live in a specific temperature range, so when ocean temperatures are too hot for a prolonged period, corals can bleach – losing the colorful algae that live within their tissue and nourish them via photosynthesis – and may eventually die.

Across the tropics, mass bleaching and die-offs have gone from being rare to a somewhat regular occurrence as the climate has warmed. More frequent heatwaves mean that the time corals have to recover is getting shorter.

In a 2018 report, the Intergovernmental Panel on Climate Change predicted that 1.5°C of global warming would cause between 70 and 90 percent of the world's coral reefs to disappear.

Now, with models capable of examining temperature differences between coral reefs one kilometer apart, our team found that at 1.5°C of warming, which the world is predicted to reach in the early 2030s without drastic action to limit greenhouse gas emissions, 99 percent of the world's reefs will experience heatwaves that are too frequent for them to recover.

That would spell catastrophe for the thousands of species that depend on coral reefs, as well as the roughly one billion people whose livelihoods and food supply benefits from coral reef biodiversity.

Climate change is already degrading coral reefs globally. Now we know that protecting the last remaining temperature refuges will not work on its own. Slashing greenhouse gas emissions this decade is the best hope for saving what remains. 

https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0...

https://theconversation.com/safe-havens-for-coral-reefs-will-be-alm...

World-Record 'Megaflash' of Lightning Stretched for Almost 500 Miles

A jaw-dropping lightning megaflash that snaked across three states in the southern US just won a world record.

A megaflash is not your standard cloud-to-ground lightning bolt. It's an enormous electric zigzag that travels from one electrified cloud to the next, almost instantaneously.

https://www.sciencealert.com/space-images-show-700-km-lightning-meg...

New insights about the toxicity of smoke produced by home stoves and power plants

The color of smoke coming out from chimneys can vary greatly based on its source and how it is produced. For instance, small coal or biomass stoves typically release dense, black smoke, while power generation plants produce lighter-colored plumes of smoke.

While these color differences are known to be linked to the different aerosols contained in smoke, so far not many studies have closely examined the major components of these aerosols and their effects on health. Researchers at Fudan University, Tsinghua University, and the Hong Kong Polytechnic University recently published a paper in Nature Energy outlining new interesting findings about the levels of toxicity of aerosols originating from different combustion sources, such as stoves in residential homes and coal-fired power plants (CFPPs).

"Differences in the color of smoke coming out from distinct chimneys can indicate different aerosols in plumes. "A crucial question is, are the major components of aerosols from these emission sources different, and can they have different health impacts? To investigate this, we collected the aerosols from large scale CFPPs and common household stoves burning wood and coal."

When researchers  analyzed the aerosols produced by CFPPs and common household stoves in the lab, they found that they had significant chemical differences. Interestingly, those emitted by household stoves primarily contained carbonaceous matter resulting from the incomplete combustion of coal or biomass material. On the other hand, large-scale powerplants that rely on efficient boilers could attain the complete combustion of fuels. This resulted in better pollution control metrics and a lower number of aerosols containing inorganic materials, such as transition and heavy metals.

In the second part of their study, the researchers used real cells from human lungs (i.e., pulmonary cells) to determine the toxicity of the inhalable particulate matter (PM) produced by household stoves and CFPPs. They specifically examined the generation of intracellular reactive oxygen species (ROS) prompted by the PM, as well as cell viability and toxicity.

Combining the chemical data with their previous information on chemical toxicity, they conducted a further aerosol toxic experiment with respiratory cells. In this experiment, they demonstrated that the toxicity of aerosols emitted from household coal/wood burning is more than 10 times higher than that from large scale coal-fired power plants.

Di Wu et al, Toxic potency-adjusted control of air pollution for solid fuel combustion, Nature Energy (2022). DOI: 10.1038/s41560-021-00951-1

https://techxplore.com/news/2022-02-insights-toxicity-home-stoves-p...

**

Scientists engineer new material that can absorb and release enormous amounts of energy

A team of researchers  recently announced in the Proceedings of the National Academy of Sciences that they had engineered a new rubber-like solid substance that has surprising qualities. It can absorb and release very large quantities of energy. And it is programmable. Taken together, this new material holds great promise for a very wide array of applications, from enabling robots to have more power without using additional energy, to new helmets and protective materials that can dissipate energy much more quickly.

A hypothetical rubber band is made out of a new metamaterial—a substance engineered to have a property not found in naturally occurring materials—that combines an elastic, rubber-like substance with tiny magnets embedded in it. This new "elasto-magnetic" material takes advantage of a physical property known as a phase shift to greatly amplify the amount of energy the material can release or absorb.

A phase shift occurs when a material moves from one state to another: think of water turning into steam or liquid concrete hardening into a sidewalk. Whenever a material shifts its phase, energy is either released or absorbed. And phase shifts aren't just limited to changes between liquid, solid and gaseous states—a shift can occur from one solid phase to another. A phase shift that releases energy can be harnessed as a power source.

 Xudong Liang et al, Phase-transforming metamaterial with magnetic interactions, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2118161119

https://phys.org/news/2022-02-scientists-material-absorb-enormous-a...

How to find a planet you can’t see

CAR-T cells hold cancer at bay

A last-resort cancer treatment called CAR-T cell therapy has kept two people leukaemia-free for 12 years. “We can now conclude that CAR T cells can actually cure patients with leukaemia,” says physician and study author Carl June. CAR-T cell therapies involve removing immune cells called T cells from a person with cancer, and genetically altering them so that they produce proteins — called chimeric antigen receptors, or CARs — that recognize cancer cells. The cells are then reinfused into the person, in the hope that they will seek out and destroy tumours. But the therapy is expensive, risky and technically demanding, and doesn’t work for everyone.

--

First COVID human challenge trial

Initial results from the first COVID-19 human challenge study show that healthy, young people developed no or mild symptoms. Such trials intentionally expose participants to a disease, providing a unique opportunity to study viral infections in detail from start to finish — but they are controversial because of the risks they pose to volunteers. The UK study of 34 individuals, aged 18–30, shows that such trials can be done safely, say scientists, and lays the groundwork for more in-depth studies of vaccines, antivirals and immune responses to SARS-CoV-2 infection.

--

Direct evidence of two types of water

Water is unlike most other liquids on Earth: it has at least 66 weird properties, including high surface tension, high heat capacity, high melting and boiling points and low compressibility. Some chemists have come to think of it as not being one liquid at all, but two distinct liquid phases that coexist in a mixture. Now, physicists might have made the first direct observation of the transformation between the two ..., in supercold water mixed with trehalose, a natural antifreeze that keeps the liquid from freezing.

There's a Bunch of Bacteria exchanging genetic material  in Your Gut, And It's Wilder Than We Thought

The human gut is the host of a rampant microscopic orgy. To survive, the microbes in our digestive tract are having 'sex' with each other on a regular basis, all in the name of swapping secrets on how to survive deadly doses of antibiotics.

A team of researchers from the University of Illinois at Urbana-Champaign and University of California Riverside has now learned just how far this bacterial bump-and-grind goes, finding exchanges that go beyond what we knew previously.

Bacteria, of course, don't have genitals, but technically 'sex' in biology refers to any process that exchanges genetic material.

By forming a 'temporary union' with another bacterium in our gut, a microbe can therefore transfer its genes to another – it doesn't even have to be the same species.

All the microbe has to do is stick out a tube, called a pilus, and attach itself to another cell, shooting off a transferable package of DNA called a mobile genetic element when it's ready.

The discovery of bacterial sex was made over 70 years ago, when scientists realized this horizontal gene transfer was how microbes were sharing resistance genes for certain antibiotics, thereby spreading antibiotic resistance.

More recently, it's become clear that bacterial sex doesn't just occur when microbes are under attack. It happens all the time, and it's probably part of what keeps our microbiome fit and healthy.

https://www.cell.com/cell-reports/fulltext/S2211-1247(21)01664-8?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2211124721016648%3Fshowall%3Dtrue

https://www.sciencealert.com/there-are-a-bunch-of-bacteria-having-s...

Three COVID-19 exposures needed for broad immunity

The immune system develops a high-quality antibody response after three encounters with the coronavirus spike protein. These antibodies are also capable of neutralizing omicron efficiently. This applies to people who are triple-vaccinated, to those having recovered and then received two vaccinations and to double-vaccinated individuals who have experienced a breakthrough infection. These are results of a study which tracked the antibodies of vaccinated and recovered individuals for two years.

Answers to the question how the immune systems can be "educated" to battle omicron and other immune escape variants of the virus are provided by a team of researchers. As they report in Nature Medicine, a total of three exposures to the viral spike protein leads to production of virus neutralizing antibodies not only in high quantity, but also high quality. These high-quality antibodies bind to the viral spike protein more vigorously and are also capable of effectively fighting the omicron variant. This applies to triple-vaccinated people, to people who have recovered from COVID-19 and then had two vaccinations, and to double-vaccinated people who then had a breakthrough infection.

In the new study the team now defined several parameters in the blood of study participants: the concentration of antibodies to the viral spike protein, the binding strength of these antibodies, and their ability to neutralize infection of SARS-CoV-2 variants in cell culture. For estimating the extent of protective immunity, the latter two parameters are particularly important. The study revealed that the ability of the immune system to neutralize the virus correlates only weakly with the antibody titer. Rather, it was critical how effectively these antibodies bind to the virus and thus disable infection.

As predicted from its many mutations, omicron exhibited the most pronounced evasion from neutralizing antibodies compared to all other viral variants tested. "For omicron, you need considerably more and better antibodies to prevent infection" . The researchers developed a new virus neutralization test, which allowed them to analyze antibodies in many serum samples and different variants of the virus at high throughput rates. A new finding of this study is that people require three separate exposures to the spike protein to build up high-level neutralizing activity against all viral variants, including omicron.

As the scientists report, various constellations are possible for these three spike encounters. Triple-vaccinated people without prior SARS-CoV-2 infection had almost the same titer and quality of neutralizing antibodies against omicron as vaccinated convalescents or people who had a breakthrough infection with delta or omicron.

In all cases, the neutralization activity reached similarly high levels and this was paralleled by an increased binding strength of the antibodies.

Paul R. Wratil et al, Three exposures to the spike protein of SARS-CoV-2 by either infection or vaccination elicit superior neutralizing immunity to all variants of concern, Nature Medicine (2022). DOI: 10.1038/s41591-022-01715-4

Nina Koerber et al, Dynamics of spike-and nucleocapsid specific immunity during long-term follow-up and vaccination of SARS-CoV-2 convalescents, Nature Communications (2022). DOI: 10.1038/s41467-021-27649-y

https://researchnews.cc/news/11427/Three-COVID-19-exposures-needed-...

Mosquitoes are seeing red: These new findings about their vision could help you hide from these disease vectors

Beating the bite of mosquitoes this spring and summer could hinge on your attire and your skin. New research indicates that a common mosquito species—after detecting a telltale gas that we exhale—flies toward specific colors, including red, orange, black and cyan. The mosquitoes ignore other colours, such as green, purple, blue and white. The researchers think these findings help explain how mosquitoes find hosts, since human skin, regardless of overall pigmentation, emits a strong red-orange "signal" to their eyes.

Mosquitoes appear to use odours to help them distinguish what is nearby, like a host to bite. When they smell specific compounds, like CO2 from our breath, that scent stimulates the eyes to scan for specific colors and other visual patterns, which are associated with a potential host, and head to them.

The results, published Feb. 4 in Nature Communications, reveal how the mosquito sense of smell—known as olfaction—influences how the mosquito responds to visual cues. Knowing which colours attract hungry mosquitoes, and which ones do not, can help design better repellants, traps and other methods to keep mosquitoes at bay.

There are three major cues that attract mosquitoes: your breath, your sweat and the temperature of your skin. In this study, researchers found a fourth cue: the colour red, which can not only be found on your clothes, but is also found in everyone's skin. The shade of your skin doesn't matter, we are all giving off a strong red signature. Filtering out those attractive colours in our skin, or wearing clothes that avoid those colours, could be another way to prevent a mosquito biting.

In the experiments conducted, without any odour stimulus, mosquitoes largely ignored a dot at the bottom of the chamber they were locked in, regardless of colour. After a spritz of CO2 into the chamber, mosquitos continued to ignore the dot if it was green, blue or purple in colour. But if the dot was red, orange, black or cyan, mosquitoes would fly toward it!

The olfactory gating of visual preferences to human skin and visible spectra in mosquitoes, Nature Communications (2022). DOI: 10.1038/s41467-022-28195-x

https://phys.org/news/2022-02-mosquitoes-red-vision-disease-vectors...

Mind-blowing mission to the early Universe

Your culture informs the emotions you feel when listening to music

https://theconversation.com/how-your-culture-informs-the-emotions-y...

Researchers report game-changing technology to remove 99% of carbon dioxide from air

Researchers have demonstrated a way to effectively capture 99% of carbon dioxide from air using a novel electrochemical system powered by hydrogen.

It is a significant advance for carbon dioxide capture and could bring more environmentally friendly fuel cells closer to market.

Fuel cells work by converting fuel chemical energy directly into electricity. They can be used in transportation for things like hybrid or zero-emission vehicles.

They found a way to embed the power source for the electrochemical technology inside the separation membrane. The approach involved internally short-circuiting the device.

It's risky, but they managed to control this short-circuited fuel cell by hydrogen. And by using this internal electrically shorted membrane, they were able to get rid of the bulky components, such as bipolar plates, current collectors or any electrical wires typically found in a fuel cell stack.

Now, the research team had an electrochemical device that looked like a normal filtration membrane made for separating out gases, but with the capability to continuously pick up minute amounts of carbon dioxide from the air like a more complicated electrochemical system.

In effect, embedding the device's wires inside the membrane created a short-cut that made it easier for the carbon dioxide particles to travel from one side to the other. It also enabled the team to construct a compact, spiral module with a large surface area in a small volume. In other words, they now have a smaller package capable of filtering greater quantities of air at a time, making it both effective and cost-effective for fuel cell applications. Meanwhile, fewer components mean less cost, and more importantly, provide a way to easily scale up for the market.

The research team's results showed that an electrochemical cell measuring 2 inches by 2 inches could continuously remove about 99% of the carbon dioxide found in air flowing at a rate of approximately two liters per minute. An early prototype spiral device about the size of a 12-ounce soda can is capable of filtering 10 liters of air per minute and scrubbing out 98% of the carbon dioxide, according to the researchers.

Lin Shi et al, A shorted membrane electrochemical cell powered by hydrogen to remove CO2 from the air feed of hydroxide exchange membrane fuel cells, Nature Energy (2022). DOI: 10.1038/s41560-021-00969-5

https://researchnews.cc/news/11453/Researchers-report-game-changing...

A never-before-seen way bacteria infect cells

 A child is born into a world full of bacteria, starting with the birth process, where contact with the mother during vaginal birth introduces the infant to the first cultures, which are far different (and absent) during a Caesarian section. Nursing and breast-feeding provide additional early exposure to bacteria that will later contribute to the development of the immune system and influence the central nervous system.

Bacteria can enter the body through an opening in your skin, such as a cut or a surgical wound, or through your airway and cause infections like bacterial pneumonia. They also enter and colonize in our gastrointestinal tract mainly by food sources. Bacteria that are in dirt, in milk and on plant surfaces enter our body.

Bacteria are much larger than viruses, and they are too large to be taken up by receptor-mediated endocytosis. Cells engulf the larger objects and pull them in, which is generally called endocytosis. There are many different types of endocytosis, one of which is called phagocytosis.

 Biologists  have now identified a new way that one type of bacteria invades multiple cells within a living organism.

The study, published this week in Nature Communications, describes how a new species of bacteria, Bordetella atropi, invades its roundworm host.

And it is aptly named because the bacteria changes its shape into a long thread, growing up to 100 times the usual size of one bacterium in the span of 30 hours without dividing.

By altering the genes of Bordetella atropi, the research team discovered that this invasive threading relies on the same genes and molecules that other bacteria use when they are in a nutrient-rich environment. However, these other bacteria only use this pathway to make subtly larger cells, whereas the B. atropi bacteria grows continuously.

Other bacteria often transform into threads, called filamentation, in response to dangerous environments or damage to their DNA. This lets them continue to grow in size, but delay dividing into new bacterial cells until they fix the damage caused by the stress. 

Here, however, the researchers were the first to observe filamentation as a way of spreading from cell to cell in a living organism for a purpose other than the stress response. They think that instead the new species is invading the host cells, detecting this rich environment and triggering filamentation in order to quickly infect more cells and access additional nutrients for their growth. 

Although neither the bacteria nor the roundworm  infects humans, it is possible that the spreading mechanism may also be used by human pathogens. Separately, the nutrient-induced filamentation process might be used by other  bacteria to form biofilms, which can coat the tubing of catheters and lead to complications for patients.

Tuan D. Tran et al, Bacterial filamentation as a mechanism for cell-to-cell spread within an animal host, Nature Communications (2022). DOI: 10.1038/s41467-022-28297-6

https://phys.org/news/2022-02-never-before-seen-bacteria-infect-cel...

New Discovery could help finetune immunity to fight infections, disease

New Research  by scientists supports a novel theory that the innate immune system people are born with can respond differently to specific pathogens. This quality, known as immunological specificity, was previously ascribed only to the adaptive immune system, which develops over time through disease exposure.

Published in the journal Cell Reports, the study suggests that this innate immune specificity is driven by the  nervous system and identifies a neuronal protein as a critical link in the process.

Based on an animal model, these findings hold early promise for the treatment of conditions such as sepsis, arthritis and inflammatory bowel disease, in which the innate immune system attacks the body and causes uncontrolled inflammation. They could also provide the basis for finetuning an experimental treatment that harnesses the nervous system to fight infection.

Clinical studies have shown that stimulating impaired neural circuits—either electrically or pharmacologically—can cure or alleviate many innate immune diseases. Knowing how the innate immune system generates a specific response to a particular pathogen enables us to manipulate neural circuits to adjust the intensity of the immune response as needed.

This would essentially help restore balance to the immune system, either by dialing back an excessive response that can cause prolonged inflammation, tissue damage and even death; or by boosting an insufficient response to keep an infection from getting worse. 

Jingru Sun, Neuronal GPCR NMUR-1 regulates distinct immune responses to different pathogens, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.110321. www.cell.com/cell-reports/full … 2211-1247(22)00032-8

https://medicalxpress.com/news/2022-02-discovery-finetune-immunity-...

New implant offers promise for the paralyzed

Mysterious Link Between Vitamin D And COVID-19 Reaffirmed in 'Striking' New Findings

Scientists found "striking" differences in the chances of getting seriously ill from COVID-19 when they compared patients who had sufficient vitamin D levels prior to contracting the disease, with those who didn't.

A study published recently  in research journal PLOS One found that about half of people who were vitamin D deficient before getting COVID-19 developed severe illness, compared to less than 10 percent of people who had sufficient levels of the vitamin in their blood.

We know vitamin D is vital for bone health, but its role in protecting against severe COVID-19 is less-well established. 

The latest research was the first to examine vitamin D levels in individuals prior to them contracting COVID-19, the study authors said.

The findings suggested vitamin D helped bolster the immune system to deal with viruses that attack the respiratory system.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

**

As seed-hauling animals decline, some plants can’t keep up with climate change