Category Archives: Humor and Observations

How does hand sanitizer work?

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Hand sanitizer works to kill germs, but not as well as soap and water and only if it has at least 60% alcohol in it.
(Image: © Shutterstock)

Hand sanitizers provide a convenient and effective way to clean your hands if soap and water aren’t available and your hands aren’t covered in visible dirt or grease. According to a 2019 ruling by the FDA, a product can be marketed as a hand sanitizer if it contains ethyl alcohol (also called ethanol), isopropyl alcohol (isopropanol) or benzalkonium chloride as the active ingredient.

The FDA hasn’t made a decision on whether to categorize those three ingredients as “generally recognized as safe” because the agency doesn’t think there is enough research to say. But they’re also not pulling the products from shelves. Ingredients other than those three have shown little to no evidence of being effective at killing germs and have not won the FDA’s approval.

How does hand sanitizer work?

The key ingredient in most hand sanitizers is alcohol. Chemically speaking, alcohols are organic molecules made of carbonoxygen and hydrogen. Ethanol is the chemical in alcoholic drinks and is the chemical most people are thinking of when they say alcohol. Propanol and isopropanol (isopropyl alcohol) are two other alcohols that are common in disinfectants because they’re highly soluble in water, just like ethanol.

Alcohols destroy disease-causing agents, or pathogens, by breaking apart proteins, splitting cells into pieces or messing with a cell’s metabolism, according to a 2014 review published in the journal Clinical Microbiology Reviews. Solutions with as little as 30% alcohol have some pathogen-killing ability, and the effectiveness increases with increasing alcohol concentration. Studies have shown that alcohol kills a more broad variety of bacteria and viruses when the concentration exceeds 60%, and it works faster as the concentration increases. But the effectiveness of alcohol seems to top out at about a 90-95% concentration.

Another strength of alcohol is that the bacteria it kills don’t develop a resistance to it, so alcohol doesn’t lose effectiveness with continued use.

According to the 2014 review, ethanol is so powerful that a few studies have found that in high concentrations, it’s better at getting rid of three species of disease-causing bacteria — Escherichia coliSerratia marcescens and Staphylococcus saprophyticus — compared with washing hands with regular or antibacterial soap.

Related: Hand sanitizer sold out? Here’s how to make your own.

But alcohol doesn’t work for all germs, such as norovirus; Clostridium difficile, which can cause life-threatening diarrhea; or Cryptosporidium, a parasite that causes a diarrheal disease called cryptosporidiosis, the Centers for Disease Control and Prevention says. Hand sanitizers also don’t remove harmful chemicals like pesticides or heavy metals, nor does hand sanitizer work well on especially dirty or greasy hands. So, soap and water still win the contest overall.

There are a few small-scale studies demonstrating that an alcohol-free hand sanitizer containing benzalkonium chloride as the active ingredient, at a concentration of 0.13%, is just as effective and even more effective than alcohol at getting rid of bacteria. The alcohol-free hand sanitizer that was tested was called HandClens, and the scientists who conducted the research on it worked for the now-closed laboratory that developed the product. That doesn’t mean benzalkonium chloride isn’t effective, but there doesn’t seem to be independent research to suggest that it’s better than alcohol. Plus, benzalkonium chloride might be harmful for some individuals, especially at higher concentrations, according to the Hazardous Substances Database.

According to the CDC, hand sanitizer without alcohol may not kill as many germs and may only reduce the growth of germs rather than killing them outright. The CDC recommends hand sanitizers with at least 60% alcohol in them for maximum effectiveness.

Does hand sanitizer expire?

Hand sanitizer doesn’t really expire. There will likely be an expiration date on the bottle because hand sanitizers are regulated by the FDA, which requires certain things to be on the packaging, including an expiration date. The expiration date is supposed to be the last date at which the product contains the ingredients in the amount specified on the label. Whether the manufacturer has tested how long the product meets the label claim or they just came up with an arbitrary date to determine the expiration date is mostly unknown to consumers. (Manufacturers are supposed to conduct testing, but not all do.)

Alcohol is a shelf-stable chemical according to its safety data sheet from chemical-supplier Sigma Aldrich. This means that if alcohol is kept in a sealed container at room temperature it will remain at the same concentration for a very, very long time.

However, alcohol evaporates easily because of its relatively low boiling point, and over time, as the bottle is opened and closed, some alcohol may escape and the concentration of alcohol in your hand sanitizer might start to decrease. Still, if you keep the bottle closed and at room temperature, you’re likely to have an effective product for as long you need it.

Is hand sanitizer bad for you or toxic?

Alcohols are considered safe for use as an antiseptic and generally have no toxic effect on the skin, although repeated use may cause dryness or mild irritation, according to the Hazardous Substances Database. Several studies have shown that repeated use of hand sanitizer is less irritating than repeated hand washing with soap. But damaged skin is more susceptible to irritation from alcohol.

And let’s be honest, would you rather have some mild skin irritation, or distribute and contract an illness?

Additional resources: 

  • Read more about why hand sanitizer is a good alternative to soap and water, according to the FDA.
  • Here’s more info on what the FDA considers hand sanitizers to be.
  • And here are the guidelines from the CDC on hand washing and hand sanitizer use.

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Bizarre ‘ice volcanoes’ erupt on Lake Michigan beach

A so-called ice volcano erupting on Oval Beach in Michigan

A so-called ice volcano erupting on Oval Beach in Michigan
(Image: © National Weather Service of Grand Rapids)

Ice volcanoes spewed great plumes of water on the shores of Lake Michigan last weekend, and the National Weather Service (NWS) caught the odd phenomenon in action.

During a stroll on Oval Beach on the lake’s eastern shore, located in the state of Michigan, an employee of the NWS Grand Rapids snapped a few photos of water bursting from mounds in the frigid ground. “You never know what you’ll find at the lake until you go out there,” the employee tweeted. “Today it was volcanoes.”

Despite their nickname, ice volcanoes aren’t really volcanoes at all. The cone-like mounds form at the edges of lakes, where thin sheets of ice form, and water shoots through holes in the ice, Tom Niziol, a contributor for Weather Underground’s Category 6 blog, explained in a Facebook post. Water sloshes beneath the ice sheet and builds up enough pressure to force spurts of water to the surface. If the air above is cold enough, the released water freezes over the surrounding ground, forming a mini volcano of sorts.

“[Ice volcanoes] can be very dangerous to climb on however because they are hollow and built over that hole in the ice,” Niziol said. “Don’t ever go venturing out onto them.”

Frozen volcanoes formed along the shores of Lake Erie a few years ago, Niziol added. Although not unheard of, ice volcanoes remain a relatively rare phenomenon.

“It’s almost a ‘Goldilocks’ situation where you need just the right conditions over a period of time to get these [formations] to develop,” Matt Benz, a meteorologist for AccuWeather, said in a news report. Ice volcanoes typically form near large bodies of water where below-freezing temperatures allow an ice shelf to form over the water’s surface along the coastline, he said. Simultaneously, waves beneath the shelf must be powerful enough to crack the ice and push water out. For this reason, ice volcanoes tend to form along shorelines where winds churn up waves consistently, Benz said.

On Feb. 16, when the Oval Beach volcanoes were spotted, the wind was almost due west, which would have been “ideal for pushing waves right into the shoreline at this location,” Benz added. Due to their enormous size, the Great Lakes may be more likely to form ice volcanoes along their shores than smaller lakes whose water completely freezes over in winter, before much ice can build up along their beaches, he said.

So if you want to see an ice volcano in person, the Great Lakes may be your best bet — but be wary where you step!

So-called ice volcanoes erupting on Oval Beach in Michigan

So-called ice volcanoes erupting on Oval Beach in Michigan (Image credit: National Weather Service of Grand Rapids)

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‘Exquisite’ dinosaur-age cockroaches discovered preserved in amber

A pair of 99-million-year-old cockroaches are rewriting the early history of the underworld.

The ancient roaches, found preserved in amber in Myanmar, are the oldest-known examples of “troglomorphic” organisms — creatures that adapted to the weird, dark environments of caves. And they’re the only such dark-adapted creatures known from the Cretaceous period, having scurried around in the world’s shaded crevices even as Tyrannosaurus rex walked the Earth. Nowadays, biologists have plenty of examples of cockroaches and of cave-dwelling insects with small eyes and wings, pale bodies, and long arms and antennae. But these specimens, from two distinct, related species, are the oldest animals ever found with those traits.

“Caves lack unequivocal fossils before the Cenozoic,” the researchers wrote in a paper describing their find, referring to a later period after the mass extinction (known as the K/Pg boundary) when dinosaurs died and mammals rose to their current prominence.

And even cave fossils from after the extinction tend to be of animals that spent only some of their time in caves, using them as shelters in between excursions into the sunlit world.

“Cave environments are well suited for fossilization of bones and coprolites [or fossilized feces] and the fossil record of cave mammals includes rodents, ungulates, marsupials, ursids, felids, hyaenids, canids, primates and humans,” they wrote — all species with plenty of bones and poop. They added that “there is no relevant fossil record of any troglomorphic fauna before K/Pg with the exception of the present find.”

Until now, the history of cave-dwelling cockroaches was known to go back to the Cenozoic era, which began about 65 million years ago. But researchers had long suspected that cave-dwelling roaches might date back to the dinosaur age, the researchers wrote, based on genetic analyses. But there had never before been firm evidence.

These two “exquisitely preserved” species, they said, according to a news article on Phys.org, were likely descendants of a common ancestor from earlier in the Cretaceous, before continental drift separated their homes on the supercontinent Gondwana.

It’s not clear, the researchers noted, how the roaches ended up so well preserved. Amber fossils are common for small creatures that live near trees, because amber is fossilized tree resin. It’s possible, the researchers suggested, that ancient resin dripped from tree roots into the cockroaches’ caves and then hardened around the paleo-arthropods.

The study researchers, hailing from several institutions in Slovakia, China, Russia and Thailand, detailed their discovery online Feb. 11 in the journal Gondwana Research.

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Weird ‘watermelon snow’ pics show Antarctic turning red

Snow that looks like it was mixed with food coloring is not what you’d expect to see in Antarctica — or anywhere else, for that matter.

But that’s the bizarre phenomenon scientists recently photographed on an Argentine island in Antarctica.

The images, depicting a watermelon-colored snow, were revealed by Ukraine’s Ministry of Science and Education. Warmer weather during the Antarctic summer prompts the spores to germinate, triggering an algae bloom that creates these weird pockets of pink “watermelon snow,” the Daily Mail reported.

The bright red photosynthetic algae — which can thrive in very low temperatures — are located in snowfields around the world.

Scientists have photographed amazing images of 'watermelon snow' in Antarctica.

Scientists have photographed amazing images of ‘watermelon snow’ in Antarctica. ((Ministry of Science Ukraine; EAS))

The Ukrainian scientists told the Mail: “Such snow contributes to climate change, because the red-raspberry color snow reflects less sunlight and melts faster.”

By Christopher Carbone | Fox News

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Ancient engraving of warrior with ‘elaborate hairstyle’ and ‘pronounced butt’ discovered in Scotland

The Tulloch stone depicts a spear-holding ancient warrior.

The Tulloch stone depicts a spear-holding ancient warrior.
(Image: © Mark Hall et. al ; Antiquity 2020)

Archaeologists in Scotland have discovered an ancient monolith that’s engraved with a spear-holding warrior sporting an “elaborate hairstyle” and “pronounced” butt.

In September 2017, construction workers uncovered the stone monument in the northwest side of Perth in Scotland while clearing the ground to build a new road. They found the stone facedown and buried a little more than 3 feet (1 meter) in the ground

The so-called Tulloch stone is about 6.4 feet (1.9 m) high and 2.3 feet (0.7 m) wide; on one side, it depicts a human figure holding a spear with a “kite-shaped blade and a doorknob-style butt,” the authors wrote in a paper describing the findings, published Jan. 23 in the journal Antiquity.

The stone was buried near a ring ditch, possibly indicating that the monolith was part of a burial, according to the paper. The carving belonged to the Picts, an ancient, Celtic-speaking group that lived in what is now eastern and northern Scotland. (The Romans coined the name “Picts,” meaning the “painted people,” possibly in reference to the Picts’ distinctive tattoos or the war paint they wore.)

In the late Roman period, the Picts helped to defend the area that’s now known as Scotland from multiple Roman attacks; as such, in the early medieval period that followed, war became an important part of how the Picts’ society was organized.

We know from historical records and poetry that “the warrior is an essential part of society, the central part of power,”  said senior author Gordon Noble, a professor in the school of geosciences at the University of Aberdeen in the United Kingdom. Pictish society adopted a warrior way of life initially as a “form of resistance” against the Roman empire, but it later became an “inspiration” and a key part of their culture, he added.

It’s not clear what the warrior on this monolith — and similar ones previously found nearby depicting warrior figures holding “doorknob-butted spears” — represent, but they could be depictions of warrior gods or religious figures within this war-oriented Pictish ideology, Noble told Live Science. War ideology was common across a large part of Europe but was more typically represented through the burial of weapons with the dead.

Such burials, historical sources and poetry that depict  the “heroic warrior ethos” were common across Northern Europe but largely absent from northern Britain in the first millennium A.D. Rather, in northeastern Scotland, such values were publicly shown with carvings on monuments and likely associated with cemeteries belonging to the elite, the researchers noted in the paper.

The Tulloch stone is only one of three such Pictish monoliths found in the area with carvings of warriors on them. But there have been numerous other Pictish stones found with carvings of abstract or animal symbols often thought to be a simple way of representing names, Noble said.

“Over the last 10 years, it seems like we’ve had a new Pictish stone every year or even more than one every year,” Noble said. “So I’m sure more will come up, but the stones with images of warriors are still quite rare in the wider Pictish stone corpus.” The stone will eventually be put on display in the Perth Museum in Scotland.

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Cyborg locusts could be used to sniff out bombs, scientists say

Could cyborg locusts be the bomb-sniffing dogs of the future?

Scientists who received funding from the U.S. Navy revealed last week that they were able to program the bugs to sense various different smells, including from explosives.

The team’s preprint research paper, published in BioRxiv, states that the insects have been used to detect gases released by substances such as ammonium nitrate – often used by terrorist groups for bomb-making – as well as military explosives TNT and RDX.

The robot-bound locusts were exposed to five different explosives, and it only took 500 milliseconds of exposure for a distinct pattern of activity to appear in the locusts’ brains. The scientists chose locusts because their tiny antennae are filled with about 50,000 olfactory neurons.

 

Scientists put sensors on the insects to monitor neural activity and decode the odors presents in the environment. (Baranidharan Raman)

Scientists put sensors on the insects to monitor neural activity and decode the odors presents in the environment. (Baranidharan Raman) (Baranidharan Raman)

Researchers chose locusts because they are sturdy and can carry heavy payloads, according to the preprint paper. They implanted electrodes into the insects’ brains to analyze their neural activity when they were around different substances.

The U.S. Office of Naval Research had allocated $750,000 for the project back in 2016.

Although the team has not commented about its new work, lead scientist Baranidharan Raman, associate professor of biomedical engineering in the School of Engineering and Applied Science at Washington University at St. Louis, expressed optimism when he received the grant.

“We expect this work to develop and demonstrate a proof-of-concept, hybrid locust-based, chemical-sensing approach for explosive detection,” Raman told The Source.

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‘Curse tablets’ found in 2,500-year-old Greek well

Archaeologists have unearthed 30 tablets, each engraved with curses, at the bottom of an ancient well in Greece, according to a report.

The small “curse tablets” discovered in the Kerameikos cemetery in Athens invoke the gods of the underworld in order to cause harm, or curse, others.

Jutta Stroszeck, director of the excavation on behalf of the German Archaeological Institute in Athens, told Greek City Times last week that it’s unclear who ordered the curses because they are never mentioned by name — unlike the recipient.

Curses on tablets were fairly typical practices in ancient Rome and Greece, according to historians. The tablets date back to the fourth century BCE.

Thirty curse tablets have been found in an ancient well in the Athenian cemetery Kerameikos (seen here).

Thirty curse tablets have been found in an ancient well in the Athenian cemetery Kerameikos (seen here). (Chris Hellier/Corbis/Getty)

Christopher Faraone, a professor of classics at the University of Illinois, said that in ancient Athens, most curses were not about killing a person.

“Most of the curses are what we call binding spells: they aim at binding or inhibiting the performance of a rival. A lot of them have to do with legal cases. They say things like, ‘Bind the tongue and the thoughts of so-and-so, who is about to testify against me on Monday,'” Faraone said in a question-and-answer. “We have some that are aimed at rival musicians or actors, and a couple that seem to be connected with athletics. We have some that run something like this, ‘Bind Helen, so that she is unsuccessful when she flirts or makes love with Demetrius.’ But the great majority of them seem to be connected with lawsuits.”

Kerameikos is named after a community of potters that once lived there, according to the Greek Ministry of Culture and Sports.

Besides tablets, the team also found pottery for drinking, some wooden products, cooking pots, clay lamps and bronze coins.

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