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Asymptomatic infection blunder let Covid-19 spin out of control

“Today, the best evidence suggests that about half of Covid-19 cases are caused by infected people who do not have symptoms when they pass on the virus.”

Asymptomatic infection blunder let Covid-19 spin out of control

Daniel P. Oran and Eric J. Topol writing for STAT.

At least one of three people infected with SARS-CoV-2, the virus that causes Covid-19, do not develop symptoms. That’s the conclusion of a review we just published in the Annals of Internal Medicine. It summarizes the results of 61 studies with more than 1.8 million people.

… But during much of the pandemic, fierce resistance — and even outright denialism — in acknowledging this not-so-typical disease pattern led to ineffective testing practices that allowed the pandemic to spin out of control.

In June, when we published a report of 16 cohorts with sizable proportions of asymptomatic infection and suggested that it might play a role in the progression of the pandemic, several researchers wrote letters to the editor demanding that our paper be retracted.

Today, the best evidence suggests that about half of Covid-19 cases are caused by infected people who do not have symptoms when they pass on the virus. These symptom-free spreaders are roughly divided between those who later develop symptoms, known as pre-symptomatic individuals, and those who never develop symptoms.

While the importance of asymptomatic infection in understanding Covid-19 has been surprising to some, infectious disease experts have long known that infection without symptoms is common in many illnesses. More than 90% of people infected with poliovirus have no symptoms. And about 75% of influenza infections have been estimated to be asymptomatic. Yet these important precedents have largely been ignored.

Asymptomatic coronavirus infection is not necessarily benign. Several studies have reported abnormal lung scans in those infected without symptoms, as well as myocarditis, a type of heart inflammation. The long-term health implications of asymptomatic infection aren’t known.

Even though knowledge about asymptomatic infection has greatly evolved, tactics for combating the pandemic have not. It is now obvious that testing only those with symptoms, as was common early in the pandemic, is a mistake because it ignores the invisible legions of infected people who have no symptoms.

This entry was tagged. COVID-19 Research Science

FDA bans antibacterial soaps

FDA bans antibacterial soaps →

Beth Mole reports, for Ars Technica.

In a final ruling announced Friday, the Food and Drug Administration is pulling from the market a wide range of antimicrobial soaps after manufacturers failed to show that the soaps are both safe and more effective than plain soap. The federal flushing applies to any hand soap or antiseptic wash product that has one or more of 19 specific chemicals in them, including the common triclosan (found in antibacterial hand soap) and triclocarbon (found in bar soaps). Manufacturers will have one year to either reformulate their products or pull them from the market entirely.

As Ars has reported previously, scientists have found that triclosan and other antimicrobial soaps have little benefit to consumers and may actually pose risks. These include bolstering antibiotic resistant microbes, giving opportunistic pathogens a leg up, and disrupting microbiomes. In its final ruling, issued Friday, the FDA seemed to agree. “Consumers may think antibacterial washes are more effective at preventing the spread of germs, but we have no scientific evidence that they are any better than plain soap and water,” Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research (CDER), said in a statement. “In fact, some data suggests that antibacterial ingredients may do more harm than good over the long-term.”

Poor Sleep Gives You the Munchies, Study Says

Poor Sleep Gives You the Munchies, Study Says →

Courtesy of Jonah Bromwich, at the New York Times:

A study published on Tuesday in the journal SLEEP suggested that the brain receptors that can lead the sleep-deprived to crave unnecessary food were the same as those activated by marijuana. Essentially, not sleeping can give you a ferocious case of the munchies.

The study took a close look at receptors affected by endocannabinoids — so named for cannabis, the marijuana plant — which it found were closely involved in the food cravings that come from sleep deprivation. Sleep restriction in the study’s subjects led to amplified endocannabinoid levels in the blood, leading to hunger pangs, which generally intensify in the early afternoon, to increase further.

Subjects who were deprived of sleep said that they felt hungrier, and had more trouble controlling themselves when faced with the snacks. They ended up consuming nearly twice as much fat and protein as the control group. (There was not a significant difference between the calories consumed by each group during regular meals.) Previous studies have shown that the sleep-deprived are particularly vulnerable to foods that are high in fat and carbohydrates.

I can confirm these results from my own anecdotal evidence.

This entry was tagged. Food Research Science

How the Microwave Was Invented by Accident

How the Microwave Was Invented by Accident →

What a great story, from Popular Mechanics.

The microwave is beloved for its speed and ease of use. But what you might not know about your indispensable kitchen appliance is that it was invented utterly by accident one fateful day 70 years ago, when a Raytheon engineer named Percy Spencer was testing a military-grade magnetron and suddenly realized his snack had melted.

​> …

Spencer earned several patents while working on more efficient and effective ways to mass-produce radar magnetrons. A radar magnetron is a sort of electric whistle that instead of creating vibrating sound creates vibrating electromagnetic waves. According to Michalak, at the time Spencer was trying to improve the power level of the magnetron tubes to be used in radar sets. On that fateful day in 1946, Spencer was testing one of his magnetrons when he stuck his hand in his pocket, preparing for the lunch break, when he made a shocking discovery: The peanut cluster bar had melted. Says Spencer, "It was a gooey, sticky mess."

​> Understandably curious just what the heck had happened, Spencer ran another test with the magnetron. This time he put an egg underneath the tube. Moments later, it exploded, covering his face in egg. "I always thought that this was the origin of the expression 'egg in your face'," Rod Spencer laughs. The following day, Percy Spencer brought in corn kernels, popped them with his new invention, and shared some popcorn with the entire office. The microwave oven was born.

No More “Moonshots”

No More “Moonshots” →

Jonathan M. Gitlin, writing for Ars Technica, criticized the President's dramatic call for a large program to end cancer.

So what's wrong with this idea, and why am I coming off like a cranky old man shouting at the clouds? For one thing, history has shown us that giving science a large slug of cash in a very short amount of time has horrible—some might say disastrous—consequences. This was plain to see after the NIH budget got doubled between 1998 and 2003 (something I and my colleagues wrote about extensively here at Ars). It was even more obvious once the two-year bolus of money from the American Recovery and Reinvestment Act (2009-2011) was spent.

Think about the way a sudden influx of nutrients causes algae to bloom and then die off in rivers and oceans, leaving dead zones behind. Rapid injections of cash into the research enterprise create intense periods where there's lots of money available for lots of new scientists to get hired. But once those initial grants run out, there is no more funding to support them.

As a result of the past booms in funding, you will find empty lab after empty lab in research institutes and universities all over the land. We've trained far more scientists than we have money to sustainably support.

​Instead of massive projects based around nebulous goals, he wants to see a sustained commitment to ongoing research.

Which brings me back to my initial point. The way to improve the health of our nation isn't another moonshot where we're not quite sure what we even mean by "Moon." Just find a way to deliver predictable, sustainable funding.

I promise you, the scientists will do the rest.

Predictable budget growth would allow scientists to build labs, do research over a long period of time, and provide opportunities for new scientists to enter the field and contribute their own research. It's an argument that seems sound to me. ​

This entry was tagged. Science Spending

How We Get the Smell of Rain

How We Get the Smell of Rain →

They found that at the right velocity on the right kind of soil (sandy clay works, but sand doesn’t) a falling water drop can trap tiny air bubbles under it. Those bubbles capture molecules in the soil. As the water drop deforms, the bubbles scoot up through the drop and jet out into the air, like champagne bubbles or spray from a crashing wave.

If the drop falls too slowly, it is absorbed; too fast, and it splatters without the bubbles emerging. “The sweet spot has to do with the velocity of the droplet and the qualities of the soil,” said Cullen R. Buie, an assistant professor of mechanical engineering. He and a postdoctoral researcher, Youngsoo Joung, reported on their work in Nature Communications.

This entry was tagged. Science

Stay Cold to Lose Weight?

Stay Cold to Lose Weight? →

My wife thinks I keep the temperature too cold as it is. I don't think she'd be a fan of this line of research.

The mild cold exposure he advocates might be as simple as forgoing a jacket when you’re waffling over whether you need one, not layering cardigans over flannels despite the insistence of the fall catalogs, or turning off the space heater under your desk. And if you don’t want to annihilate the environment by running the air conditioner to get a taste of sweet, calorie-burning, metabolism-enhancing cold in the summer, there are devices like the ice vest, which really isn’t as terrible as it sounds.

“The first time you put it on, it’s a bit shocking, to be honest,” Wayne Hayes, the vest’s inventor, warned me. “You feel like, Holy shit, this is cold.” But after wearing it a few times, he said, most people barely notice they have it on. That was my experience. (Hayes’s wife has become so used to the vest that she wears it under her clothes instead of over them.) Hayes recommends wearing the vest twice a day until the ice melts—which can take an hour or longer—though he has himself worn it as many as three or four times in a single day.

Vast Study Casts Doubts on Value of Mammograms

Vast Study Casts Doubts on Value of Mammograms →

Interesting.

One of the largest and most meticulous studies of mammography ever done, involving 90,000 women and lasting a quarter-century, has added powerful new doubts about the value of the screening test for women of any age.

It found that the death rates from breast cancer and from all causes were the same in women who got mammograms and those who did not. And the screening had harms: One in five cancers found with mammography and treated was not a threat to the woman’s health and did not need treatment such as chemotherapy, surgery or radiation.

… an editorial accompanying the new study said that earlier studies that found mammograms helped women were done before the routine use of drugs like tamoxifen that sharply reduced the breast cancer death rate. In addition, many studies did not use the gold-standard methods of the clinical trial, randomly assigning women to be screened or not, noted the editorial’s author, Dr. Mette Kalager, and other experts.

Dr. Kalager, an epidemiologist and screening researcher at the University of Oslo and the Harvard School of Public Health, said there was a reason the results were unlike those of earlier studies. With better treatments, like tamoxifen, it was less important to find cancers early. Also, she said, women in the Canadian study were aware of breast cancer and its dangers, unlike women in earlier studies who were more likely to ignore lumps.

“It might be possible that mammography screening would work if you don’t have any awareness of the disease,” she said.

This entry was tagged. Science