popular science

World Health Organization: Limit Headphone Time To An Hour A Day 

Cranking up the tunes today may lead to the inability to hear them tomorrow, according the World Health Organization. Young people tend to turn the volume too high on their mobile music devices, as well as frequent noisy concerts and clubs. As a result, over 1.1 billion people ages 12-35 are at risk of hearing loss, the WHO said in a recent statement.

Some studies have shown that the number of young people with damaged hearing has increased over the past decade, likely because of the heightened use of iPods and smartphones to play loud music. In 1994, 3.5 percent of American teens experienced hearing loss, but that number rose to 5 percent by 2006. To combat this increase, the WHO recommends listening to mobile devices for a maximum of one hour per day, and the volume should stay around 60 percent.

The idea is to minimize unsafe listening practices, which depend on two factors: how long you listen and how loud the sound is. The sound of a typical conversation is 60 decibels, which won’t cause any hearing problems. But an idling bulldozer is about 85 decibels, which can cause permanent damage after eight hours. Sounds like a clap of thunder or even a close vuvuzela clock in at 120 decibels, damaging hearing after just nine seconds. Hearing loss from these loud, sustained sounds can be immediate, or they build up over time as the delicate structures in the inner ear become more and moredamaged.

However, headphones can be both good and bad for our auditory health, according to Kathleen Campbell, a professor at Southern Illinois University School of Medicine who specializes in audiology. Over-ear or noise-canceling headphones are ideal, because they encourage people to turn down the volume of the music they’re playing. People tend to prefer their music to be proportionally louder than any background noise, but if they can’t hear that noise, they’re not as inclined to turn up the music’s volume. Leaky headphones, however, make us more likely to turn up the volume, which can be bad news; headphones at maximum volume can impair hearing in just four minutes, and many young people don’t even realize that those deafening effects can be permanent.

To prevent hearing loss even further, WHO notes that headphone manufacturers and government regulators should do their part to develop listening devices that don’t irrevocably affect listeners. Loud venues like concerts or clubs should offer earplugs or quiet spaces where patrons can give their ears a break.

But in the meantime, WHO says it’s up to listeners to take care of their hearing. The type of music you listen to isn’t as important as its volume or duration, Campbell says, “but aficionados of different types of music tend to have different volume preferences.” Using noise-canceling headphones may help listeners resist the temptation to turn it up.

via Popular Science

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The Top 5 Most Irritating Terms In Evolution Reporting “Evolution is misunderstood by millions.  And, it has to be said, a lot of the time, this problem isn’t helped by the way things are reported on the TV or in the news.

These are the 5 most common terms that, when I hear them used, I die a little. Though their effect is subtle, all of these terms perpetrate common myths about the way evolution works. The sooner they become extinct, the better!

1. Survival of the Fittest
Now, this term is something that often gets used synonymously with natural selection. In fact, it wasn’t actually coined by Darwin himself; it was first used by Herbert Spencer, though Darwin later came to use it extensively.

The problem with the phrase "survival of the fittest”, in my view, is that it rather misrepresents the way that selection really works. This is because it isn’t really the survival of the fittest organism that drives evolution. It’s the death of the least fit organism.

I can see how “survival of the fittest” appealed to victorian sensibilities! Instead of implying a brutal, red-in-tooth-and-claw vision of nature, it implies a striving towards self improvement. Which is, it has to be said, appealing. Unfortunately, it’s neither borne out by theory nor facts.

2. Living fossil
This is another very appealing term. Below was the best example I could find after a quick rifle through the drawers here in Leicester. It is a maple leaf next to a modernish mapleish leaf (sycamore). For some much better examples, check out the Living Fossils website" (read more).

(Source: Science 2.0)

“The tale of the clown is not a wild dream. His name is Cho-Cho, and he knows what he is talking about…

By his antics and games he impresses on the children the proper things to eat and drink, and how often to bathe, sleep, and play”

Cho-Cho knows.

Do as Cho-Cho says.

He is the health clown.

Ĥė ïŝ ťĥĕ ĥėåļťĥ ĉŀõŵñ

Antibiotic-resistant bacteria are no match for medieval potion
Recipe from Bald’s Leechbook found to be highly effective against MRSA

By Alexandra Ossola, Popular Science

Bloodletting, mercury cures, holes drilled in the head—many ancient medical remedies seem ill-advised based on our modern understanding of medicine. But researchers recently found that a thousand-year-old Anglo-Saxon treatment for eye infections works as an antibiotic against one of today’s most notorious bacteria, Methicillin-resistant Staphylococcus aureus (MRSA). The British researchers will present their findings this week at an annual microbiology conference held in the United Kingdom

Christina Lee, a professor in Viking studies at the University of Nottingham, translated the recipe from the Old English in Bald’s Leechbook, which was written in the 9th century and is one of the earliest known medical textbooks. The researchers prepared four batches of the recipe, which called for two species of garlic and onions, wine, and bile from a cow’s stomach brewed in a brass cauldron and let sit for nine days before use.

take cropleek and garlic, of both equal quantities, pound them well together, take wine and bullocks’ gall, of both equal quantities, mix with the leek, put this then into a brazen vessel, let it stand nine days in the brass vessel, wring out through a cloth and clear it well, put it into a horn, and about night time apply it with a feather to the eye; the best leechdom.

The researchers tested the concoction on cultures of MRSA bacteria in synthetic wounds as well as in rats. No individual ingredient had no effect on the cultures, but the combined liquid killed almost all the cells; only about one in 1,000 bacteria survived. At more dilute concentrations, the salve didn’t kill the bacteria, but still interrupted their communication, preventing them from damaging tissues. Some researchers have been looking into this type of communication interruption as a possible new way to treat antibiotic-resistant bacteria.

Continue Reading.

Today’s guest and author of Gulp: Adventures on the Alimentary Canal, Mary Roach in Popular Science:

Taste is a sort of chemical touch. Taste cells are specialized skin cells. If you have hands for picking up foods and putting them in your mouth, it makes sense for taste cells to be on your tongue. But if, like flies, you don’t, it may be more expedient to have them on your feet. “They land on something and go, ‘Ooh, sugar!’ ’’ Rawson does her best impersonation of a housefly. “And the proboscis automatically comes out to suck the fluids.” Rawson has a colleague who studies crayfish and lobsters, which taste with their antennae. “I was always jealous of people who study lobsters. They examine the antennae, and then they have a lobster dinner.”

The study animal of choice for taste researchers is the catfish, simply because it has so many receptors. They are all over its skin. “They’re basically swimming tongues,” says Rawson. It is a useful adaptation for a limbless creature that locates food by brushing up against it; many catfish species feed by scavenging debris on the bottom of rivers.

I try to imagine what life would be like if humans tasted things by rubbing them on their skin. Hey, try this salted caramel gelato—it’s amazing.

Image by Emily Cavalier