The science news of the week: Throughout the year, scientists have told us about the dangers of airborne transmission and warned that social distancing alone may not be enough. And although a vaccine for coronavirus has been invented and implemented, this infection continues to find new targets. Moreover, it has now been discovered that the very microdroplets containing the virus, when coughed or sneezed, travel much further than previously thought.
“In the majority of cases we simulated, the largest droplets consistently traveled a horizontal distance of two meters before falling to the ground,” explains mathematician Emiliano Renzi of Loughborough University in Leicestershire in a study published in Physics of Fluids. In their study, Rentsy and his graduate assistant, Adam Clark, modeled the dynamics of the emission of a cloud of microdroplets during coughing and sneezing using a pressurized aerosol can, similar to the ones we use when we spray medicine into our noses. In the process, they created a physical phenomenon called floating vortex rings. (Incidentally, the mushroom-shaped clouds that form during atomic explosions exhibit the same dynamics.) The existence of such a phenomenon, scientists say, proves that tiny liquid particles contained in a sneeze or cough, and potentially carrying viruses, can spread much farther than one might think, much like radioactive fallout.
According to Renzi, in some cases the vortex carried particles to a height of more than 3.5 meters, and the smallest particles – with a diameter of 30 micrometers – were lifted as high as 6 meters, where they remained suspended for a long time. Meanwhile, air-conditioned rooms are much lower, enough for particles to enter the system and spread throughout the building. We explain quickly, simply, and clearly what happened, why it matters, and what happens next. The episodes. The end of the story: Podcast Advertising
Scientists have also found that the initial direction of the dispersing cloud of fluid from the mouth or nose plays an important role in the potential spread of infection. In other words, by sneezing or coughing downwards, you can significantly reduce the spread of aerosols in a room. The researchers acknowledge that their model is based on a number of mathematical assumptions and that we know too little about the infectious potential of tiny droplets. But even without that, it’s clear that this issue needs further detailed study, and in the meantime, it wouldn’t hurt to reconsider the rules of behavior in public places and social distancing.
“Rules requiring a two-meter distance may be insufficient and do not prevent direct transmission through large droplets,” Renci said. “Therefore, we suggest reviewing cultural traditions and behaviors and, in addition to mandatory mask use, trying to cough downwards, which can reduce the risk of direct spread of respiratory viruses at close distances.”
Male chauvinism flourishes in chimpanzee society. The main friend of any self-respecting chimpanzee is a strong male. But while you are a baby, your most reliable protector is your mother. And even as they grow up, chimpanzees continue to treat their mothers with reverence, and for a third of males, the relationship with their mother remains the most important in their lives. Yes, the transition from childhood to adolescence and then adulthood is not easy for chimpanzees, they are not much different from us in that sense. And during this difficult time, chimpanzee mothers provide their sons with support that goes far beyond simple feeding. As a result, those who maintain contact with their mothers grow larger and have a significantly higher chance of survival than chimpanzees who lose their mothers before the age of 12. To determine how long such mother-son relationships can last, researchers followed 29 adolescent and juvenile chimpanzees, ages 9 to 20, for three years in Kibale National Park, Uganda. They recorded all aspects of social interaction: how the monkeys groom each other, hold hands, hug, look around and wait for others, help each other in fights, and just sit together.
It turns out that as chimpanzees grow up, they become more independent, explore new territories, and spend more time away from their mothers. Unlike teenagers, they stop constantly calling their mothers and running to complain when they are beaten up in a fight. However, as the authors of a new study (published in the journal Behavioral Ecology and Sociobiology) write, in the presence of their mothers, adult males transform back into adolescents in their relationships with their mothers. According to one of the researchers, Harvard anthropologist Rachna Reddy, such support from mothers reduces stress in men, and there is a lot of accumulated stress in conditions of constant competition. Reddy points out that similar patterns of behavior are observed in humans when sons who live apart from their mothers constantly turn to them for moral support. “The importance of such a connection in our lives and the comfort we derive from it have deep evolutionary roots,” the anthropologist believes.
Terry Steel presents a new superglue. Epoxy glue, or “epoxy” as it is colloquially known, is an indispensable tool when something needs to be repaired. However, in order for epoxy-based adhesives to cure, external factors such as heat, light, or water are required. This is not always convenient, and on an industrial scale (where glue is primarily used), it can be expensive. A fundamentally new bonding method developed by materials specialists at Nanyang Technological University in Singapore (NTU) promises to solve the problem. They have decided to use a magnetic field as a curing agent.
The new adhesive consists of a regular epoxy base and a set of magnetic iron, zinc, and magnesium nanoparticles that heat up when exposed to a magnetic field and create a bonding effect. “The key element of our discovery was that the adhesive cures within minutes when placed in a magnetic field without overheating the bonded surfaces,” explains Terry Steel, one of the developers of the new adhesive. “This is very important because there is often a need to bond heat-sensitive materials such as flexible electronics or biodegradable plastics.” The new adhesive is easier to apply, hardens faster and does not require a special accelerator or hardener. The surfaces to be bonded do not need to be placed in special large ovens – a small electromagnetic generator is sufficient. According to the developers, it takes an hour to cure one gram of ordinary epoxy adhesive in a 2000-watt oven, while one gram of magnetic adhesive cures in 5 minutes in a 200-watt oven. During the trials, the new adhesive successfully bonded wood, ceramics and plastics, proving its effectiveness and potential for use in modern production lines. According to the developers of the magnetic adhesive (the results of their research were published in Applied Materials Today), their creation can be used in a variety of fields, from sports equipment manufacturing to the aerospace industry.
