Posts Tagged ‘Rafi Letzter’

By Rafi Letzter

A 210-foot-long (64 meters) monster made from grease and used baby-wipes has clogged up a sewer in Sidmouth in southwestern England. British officials said in a statement they expect that removing the gooey blob, which will happen in “exceptionally challenging work conditions,” could take up to eight weeks.

“Fatbergs” like this one have become unpleasantly familiar in the United Kingdom. As Live Science reported back in 2017, workers used high-pressure water jets to slowly break down an 820-foot-long (250 m), 143-ton (130,000 kilograms) “rancid blob” that formed in a London sewer. Eventually, that mass was converted to biofuel, but it took workers months to fully restore function in the affected area.

Part of the problem seems to be the British public’s habit of flushing used baby wipes down the toilet, as these can clump together and form the scaffolding for fatbergs. The issue has become serious enough that the government has proposed banning the wipes altogether.

https://www.livescience.com/64447-fatberg-part-deux.html?utm_source=notification

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By Rafi Letzter

A kid in France transcribed parts of the Hebrew book of Genesis and the Arabic-language Quran, into DNA and injected them into his body — one text into each thigh.

Adrien Locatelli, a 16-year-old high school student, posted a paper Dec. 3 on the preprint server OS, in which he claimed, “It is the first time that someone injects himself macromolecules developed from a text.”

Locatelli, a student at the boarding school Lycée les Eaux Claires in Grenoble, France, told Live Science that he didn’t need any special equipment for his project.

“I just needed to buy saline solution and a syringe because VectorBuilder sent me liquid and ProteoGenix sent me powder,” he told Live Science.

VectorBuilder is a company that creates viruses that can sneak DNA strands into cells for gene-editing purposes. ProteoGenix synthesizes, among other things, custom strands of DNA. Both companies primarily serve scientists, but their products are available to anyone who purchases them.

If you saw the texts that Locatelli injected into his body, they wouldn’t look like much. DNA is just a long molecule that can store information. Mostly, it stores the information living things use to go about their business. But it can be used to store just about any kind of information that can be written down.

Locatelli’s method for translating the texts into DNA was straightforward, if a bit crude. DNA encodes its information using repeating strings of four nucleotides, which scientists have abbreviated as A, G, T and C. Locatelli lined up each letter of the Hebrew and Arabic alphabets (which correspond closely to each other) with a nucleotide, so each nucleotide represented more than one letter. So if you were to write a Hebrew sentence using his scheme, every aleph, vav, yud, nun, tsade, and tav would become a G. Every dalet, khet, ayin, and resh would become a T. And so on.

So, is this a good idea? Locatelli thinks so.

“I did this experiment for the symbol of peace between religions and science,” he said, adding, “I think that for a religious person it can be good to inject himself his religious text.”

Locatelli said he didn’t experience any significant health problems following the procedure, though he reported some “minor inflammation” around the injection site on his left thigh for a few days.

This account of only minimal complications fits with what Sriram Kosuri, a professor of biochemistry at UCLA, told Live Science.

“[The injected texts] are unlikely to do anything except possibly cause an allergic reaction. I also don’t know how likely the rAAV vector would be to make actual virus, given the way he injected. I honestly don’t know enough about the vector he used and how he did it (details are scarce),” he wrote in a message.

https://www.livescience.com/64388-boy-encoded-and-injected-dna-bible-quran.html#?utm_source=ls-newsletter&utm_medium=email&utm_campaign=12252018-ls

By Rafi Letzter

There’s a lot of cocaine and heroin in the world, and there’s a pretty good chance you’ve got a tiny bit of it on your body right now — even if you’ve never knowingly touched the stuff.

That’s the conclusion of a new paper published in the journal Clinical Chemistry today (March 22), which found that 13 percent of drug-free study participants had traces of the drugs on their fingertips. The participants, residents of the United Kingdom tested at the University of Surrey, didn’t have enough heroin or cocaine on their fingers for it to be visible, and certainly not enough to get them (or anyone) high. But they did have enough cocaine or heroin on their hands to trip very sensitive instruments called mass spectrometers.

But the point of the study wasn’t just to reveal that there’s a whole lot of trace narcotics floating around out there.

Instead, researchers were trying to establish a baseline for how much trace heroin or cocaine would turn up in a non-drug user’s fingerprint. (When a person does a fingerprint test, some of the substances on their fingertips are transferred to the print.) They compared non-drug users’ fingerprints to the fingerprints of recent heroin or cocaine users, in hopes of establishing a level over which they could confidently say the fingerprint belonged to someone who had recently used drugs.

While they did arrive at such a cutoff, they also found that there’s a lot of environmental contamination on people’s fingers — and that it doesn’t go away when study participants wash their hands.

Chemists already knew that trace amounts of cocaine and heroin are everywhere, said Rolf Halden, director of the Biodesign Center for Environmental Health Engineering at Arizona State University.

“Think of cocaine on paper money,” Halden told Live Science. “We know that a lot of currency is contaminated with cocaine.”

Halden would know: His lab collects sewage water samples from all over the world and tests them for traces of drugs. While most people might not admit to using drugs, he can tell how much certain drugs are actually getting used in a given city based on the traces they leave in the sewage system.

Still, Halden said, the fingerprint finding is new and interesting, and could represent a method of quick drug testing that’s less invasive than drawing blood or collecting hair samples.

That said, Halden cautioned that the results would be much more uncertain than those existing methods. Where people live and which things they regularly touch might lead to a wide range of baseline-level drug traces among different people. A bank teller or tollbooth operator, he speculated, might have much more significant drug traces just from touching cash all day.

“If I’m a lawyer and my client tested for drugs this way, this would be an easy way out [of a conviction],” he said. “I predict it could be potentially helpful [for drug testing], but it would not very rapidly replace other types of testing, like bodily fluids.”

While it might surprise readers to learn they have a reasonably good chance of having drugs they’ve never used on their fingertips, Halden said it’s nothing to worry about.

“The levels are way too low to be consequential,” he said.

The reality is that chemists’ instruments are so sensitive that they can detect even the tiniest traces of substances.

“We also can detect a lot of prescription drugs in drinking water,” Halden said. “There [are] a few molecules in there — enough for us to detect them as analytical chemists, but not enough to have a measurable impact on people.”

In other words, no one’s getting high from finger-molecules of old cocaine on their banknotes. And they don’t represent any kind of individual danger to anyone.

That said, Halden added, there just isn’t enough data yet to know if there might be some kind of population-level effect from this kind of widespread contamination. But if it’s there, he said, it’s vanishingly subtle — to the point of having zero measurable effect on any one individual — and people should not worry about it.

https://www.livescience.com/62099-cocaine-heroine-drug-finger-fingerprints.html?utm_source=notification

By Rafi Letzter

Russian scientists have a plan to deal with a hypothetical asteroid threat that’s straight out of the movie “Armageddon.”

A team of government scientists has proposed that nuclear weapons well within the power of those already developed could be used to break up incoming asteroids, protecting the planet from a major asteroid strike. They then demonstrated, in a paper published online March 8 in the Journal of Experimental and Theoretical Physics, the effect of a nuclear strike on an asteroid, using scale model “asteroids” and powerful lasers.

Striking a tiny model asteroid with a powerful laser on Earth is obviously not the exact same thing as striking a full-size asteroid with a laser out in space. But there’s a reasonable degree of comparison between the two situations.

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Russian Scientists Tested Their Asteroid-Nuking Plan with Powerful Lasers
This photo of the asteroid Eros was taken during the NEAR Shoemaker mission.
Credit: NASA
Russian scientists have a plan to deal with a hypothetical asteroid threat that’s straight out of the movie “Armageddon.”

A team of government scientists has proposed that nuclear weapons well within the power of those already developed could be used to break up incoming asteroids, protecting the planet from a major asteroid strike. They then demonstrated, in a paper published online March 8 in the Journal of Experimental and Theoretical Physics, the effect of a nuclear strike on an asteroid, using scale model “asteroids” and powerful lasers.

Striking a tiny model asteroid with a powerful laser on Earth is obviously not the exact same thing as striking a full-size asteroid with a laser out in space. But there’s a reasonable degree of comparison between the two situations. [Crash! The 10 Biggest Impact Craters on Earth]

The researchers took careful steps to make sure the scale models were created from the same materials and had similar structures to chondrites (common, stony asteroids). And the immense energy deposited by a pulsed laser onto a single point on the model was reasonably similar to the effect of a nuclear blast on a single point on the asteroid’s surface. They wrote that their experiment showed they could use a a 3-megaton bomb to blast a 656-foot-wide (200 meters) asteroid — 10 times wider than the asteroid that detonated over Russia in 2013 — to harmless bits that would spread out and miss Earth.

The first thermonuclear weapon ever detonated had a strength of about 10.4 megatons, according to the Nuclear Weapon Archive. That bomb was detonated on Elugelab Island, Enewetak Atoll, in the Pacific Ocean in 1952.

There are other methods for diverting incoming asteroids, the researchers acknowledged, like the gravity tug— using the force of gravity to move the space rock to a better orbit. But they require more advanced knowledge of the incoming strike and planning. The advantage of a nuclear strike, they wrote, is that it can work against even surprise asteroids discovered late.

Russia isn’t alone in considering the possibility of a nuclear strike on an asteroid. U.S. government researchers also raised the possibility in a February paper.

https://www.livescience.com/62057-asteroid-nuclear-bomb-russia-laser.html?utm_source=notification

By Rafi Letzter

“Magic” mushrooms seem to have passed their genes for mind-altering substances around among distant species as a survival mechanism: By making fungus-eating insects “trip,” the bugs become less hungry — and less likely to feast on mushrooms.

That’s the upshot of a paper published Feb. 27 in the journal Evolution Letters by a team of biologists at The Ohio State University and the University of Tennessee.

The researchers studied a group of mushrooms that all produce psilocybin — the chemical agent that causes altered states of consciousness in human beings — but aren’t closely related. The scientists found that the clusters of genes that caused the ‘shrooms to fill themselves with psilocybin were very similar to one another, more similar even than clusters of genes found in closely related species of mushrooms.

That’s a sign, the researchers wrote, that the genes weren’t inherited from a common ancestor, but instead were passed directly between distant species in a phenomenon known as “horizontal gene transfer” or HGT.

HGT isn’t really one process, as the biologist Alita Burmeister explained in the journal Evolution, Medicine and Public Health in 2015. Instead, it’s the term for a group of more or less well-understood processes — like viruses picking up genes from one species and dropping them in another — that can cause groups of genes to jump between species.

However, HGT is believed to be pretty uncommon in complex, mushroom-forming fungi, turning up much more often in single-celled organisms.

When a horizontally transferred gene takes hold and spreads after landing in a new species, the paper’s authors wrote, scientists believe that’s a sign that the gene offered a solution to some crisis the organism’s old genetic code couldn’t solve on its own.

The researchers suggested — but didn’t claim to prove — that the crisis in this case was droves of insects feasting on the defenseless mushrooms. Most of the species the scientists studied grew on animal dung and rotting wood — insect-rich environments (and environments full of opportunities to perform HGT). Psilocybin, the scientists wrote, might suppress insects’ appetites or otherwise induce the bugs to stop munching quite so much mush’.

https://www.livescience.com/61877-magic-mushrooms-evolution.html