828cloud

Data, Info and News of Life and Economy

Daily Archives: January 12, 2022

Chart: U.S. Real Average Hourly Earnings YoY Fell in December 2021

Earning growth has been negative for the last nine months

Source : Bloomberg

Humour: News in Cartoons

Study: COVID Loses 90% of Ability to Infect Within 20 minutes in Air

Linda Geddes wrote . . . . . . . . .

Coronavirus loses 90% of its ability to infect us within 20 minutes of becoming airborne – with most of the loss occurring within the first five minutes, the world’s first simulations of how the virus survives in exhaled air suggest.

The findings re-emphasise the importance of short-range Covid transmission, with physical distancing and mask-wearing likely to be the most effective means of preventing infection. Ventilation, though still worthwhile, is likely to have a lesser impact.

“People have been focused on poorly ventilated spaces and thinking about airborne transmission over metres or across a room. I’m not saying that doesn’t happen, but I think still the greatest risk of exposure is when you’re close to someone,” said Prof Jonathan Reid, director of the University of Bristol’s Aerosol Research Centre and the study’s lead author.

“When you move further away, not only is the aerosol diluted down, there’s also less infectious virus because the virus has lost infectivity [as a result of time].”

Until now, our assumptions about how long the virus survives in tiny airborne droplets have been based on studies that involved spraying virus into sealed vessels called Goldberg drums, which rotate to keep the droplets airborne. Using this method, US researchers found that infectious virus could still be detected after three hours. Yet such experiments do not accurately replicate what happens when we cough or breathe.

Instead, researchers from the University of Bristol developed apparatus that allowed them to generate any number of tiny, virus-containing particles and gently levitate them between two electric rings for anywhere between five seconds to 20 minutes, while tightly controlling the temperature, humidity and UV light intensity of their surroundings. “This is the first time anyone has been able to actually simulate what happens to the aerosol during the exhalation process,” Reid said.

The study, which has not yet been peer-reviewed, suggested that as the viral particles leave the relatively moist and carbon dioxide-rich conditions of the lungs, they rapidly lose water and dry out, while the transition to lower levels of carbon dioxide is associated with a rapid increase in pH. Both of these factors disrupt the virus’s ability to infect human cells, but the speed at which the particles dry out varies according to the relative humidity of the surrounding air.

When this was lower than 50% – similar to the relatively dry air found in many offices – the virus had lost around half of its infectivity within five seconds, after which the decline was slower and more steady, with a further 19% loss over the next five minutes. At 90% humidity – roughly equivalent to a steam or shower room – the decline in infectivity was more gradual, with 52% of particles remaining infectious after five minutes, dropping to about 10% after 20 minutes, after which these was no difference between the two conditions.

However, the temperature of the air made no difference to viral infectivity, contradicting the widely held belief that viral transmission is lower at high temperatures.

“It means that if I’m meeting friends for lunch in a pub today, the primary [risk] is likely to be me transmitting it to my friends, or my friends transmitting it to me, rather than it being transmitted from someone on the other side of the room,” said Reid. This highlights the importance of wearing a mask in situations where people cannot physically distance, he added.

The findings support what epidemiologists have been observing on the ground, said Dr Julian Tang, a clinical virologist at the University of Leicester, adding that “masks are very effective … as well as social distancing. Improved ventilation will also help – particularly if this is close to the source.”

Dr Stephen Griffin, associate professor of virology at the University of Leeds, emphasised the importance of ventilation, saying: “Aerosols will fill up indoor spaces rapidly in the absence of proper ventilation, so assuming the infected individual remains within the room, the levels of virus will be replenished.”

The same effects were seen across all three Sars-CoV-2 variants the team has tested so far, including Alpha. They hope to start experiments with the Omicron variant in the coming weeks.


Source : The Guardian

Infographic: Industry 4.0 – What Manufacturing Looks Like in the Digital Era

See large image . . . . . .

Source : Visual Capitalist

Chart: U.S. CPI YoY Surged to 39-year High in December 2021

Source : Bloomberg

Scientists Work Out How Exercise Saves Your Brain

Dennis Thompson wrote . . . . . . . . .

Exercise helps you stay fit, hale and hearty, and researchers say it may also help you stave off dementia and Alzheimer’s disease. Now they have a better understanding of the hidden benefits that aid the brain.

Older folks who are more physically active have higher levels of a protein that promotes better communication between the brain’s synapses, a new study reports.

“Synapses are these critical communicating junctions between nerve cells. They’re what sends the message from one nerve cell to another, and I think of them as where the magic happens when it comes to cognition,” said lead researcher Kaitlin Casaletto, an assistant professor of neurology with the University of California, San Francisco. “All of our thinking and memory occurs as a result of these synaptic communications.”

Even people in their 80s and 90s whose brains were riddled with amyloid plaques and tau tangles — the toxic hallmarks of Alzheimer’s — contained higher levels of these synaptic proteins if they were more active, researchers found.

The synaptic proteins are involved with the production and release of neurotransmitters, the biochemicals in the brain that promote communication between nerve cells, Casaletto said.

“We think having more of these proteins suggests that maybe you have more synapses and/or maybe your synapses are working a little bit better,” Casaletto said. “You’re getting more of that juice into the brain and facilitating communications.”

This study involved more than 400 elderly people who agreed to wear monitors that tracked their amount of daily physical activity. They were all participants in the Rush University Memory and Aging Project, a long-term effort to identify the causes of Alzheimer’s and dementia.

Researchers already had discovered that people within this group who had greater levels of physical activity also tended to have better cognitive performance and a reduced risk of dementia, Casaletto said.

The next step was to figure out why that was. Brain autopsies provided answers.

“We followed these adults until death. They donated their brains to the autopsy program, and we were able to look at the brain tissue after death,” Casaletto said. The average age of death among participants was 90.

Autopsies revealed higher levels of synaptic proteins in the brains of those who, while they lived, tended to move around more in their day-to-day lives, researchers said.

“We saw a pretty linear relationship. The more activity, the higher the synaptic protein levels. To me, this suggests every movement counts,” Casaletto said.

These levels were elevated even among people who had physical evidence of Alzheimer’s in their brains.

“The capacity of the elderly brain to mount this healthy response to activity might help buffer these age-related brain changes and help promote cognition,” Casaletto said.

Further, researchers found these elevated levels of synaptic proteins in six regions of the brain — not only in the memory center, but in other parts related to thought and reasoning as well.

“It suggests it’s more of a whole-brain phenomenon,” Casaletto said.

As people age, their brains tend to accumulate toxic proteins like amyloid beta and tau, the researchers said in background notes. As these proteins form clumps and tangles, they can interfere with synaptic communication between nerve cells and eventually cause the synapses and neurons to fall apart.

The findings suggest that physical activity can promote resilience in the brain, said Heather Snyder, vice president of medical and scientific relations at the Alzheimer’s Association.

A steady flow of neurotransmitters from these proteins might add up to better synaptic function for aging brains, maintaining communication between nerve cells despite the interference from toxic amyloid and tau.

“If you can keep brain cells healthy and communicating longer, you may slow the changes you would see in disease or you may be able to decrease the vulnerability of the brain to other injury or other insult,” Snyder said.

The study didn’t measure the vigor of each person’s physical activity, only how much they tended to move during the day, Casaletto said.

There are any number of activities you could pursue to promote brain health, Snyder said, such as ballroom dancing, neighborhood walks or riding a stationary bike at home.

“Find something that you’re going to enjoy, that you’re going to stick with and continue to do,” Snyder said, adding that seniors should check with their doctor before taking on a new activity.

The new study was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.


Source: HealthDay