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Using Nuclear Bombs to Fight Wildlife Poachers

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Getty Images

During the 1950s and '60s, the United States and the Soviet Union tested and showed off their shiny new atomic arsenals by detonating hundreds of nuclear weapons at above-ground sites. After each explosion, residual radioactive material, or fallout, was dispersed into the atmosphere and then spread around the world by the wind. 

Among these radioactive leftovers is an isotope, or variant, of the element carbon known as carbon-14. This same isotope is generated naturally by cosmic rays and normally occurs in small traces, accounting for just one part per trillion of atmospheric carbon. During the Cold War, though, scientists keeping tabs on the isotope’s concentration found a spike—a near doubling—in carbon-14 levels that coincided with the start of the weapons tests, and a slow, steady decline when the tests were moved underground. It was dubbed the “bomb curve.”

Most carbon-14, whether it’s natural or man-made, American or Soviet, oxidizes into carbon dioxide, and then gets taken in by the oceans and by plants. As animals eat these plants and other animals eat those animals, almost every living thing gets a share of carbon-14 incorporated into its teeth or tusks or hair or horns. 

Anyone or anything that was alive during the Cold War got to keep a small souvenir from it inside its body—not enough to do any damage, but enough to date it. If the carbon-14 concentration in some animal or plant tissue is the same as the known level in the atmosphere at a certain date along the bomb curve, that gives you an idea of how old the tissue and the creature it came from is. 

In a study led by doctoral student Kevin Uno, a team of researchers from the University of Utah chased down more than two dozen animal tissue samples that had been collected between 1955 and 2008. Previous studies on bomb curve carbon dating had mostly only looked at tree rings and enamel from human teeth, but Uno and company gathered everything from hair from a blue monkey to teeth from hippos and tusks from elephants to stems from various plants. They measured the carbon-14 levels in these samples and then plotted them along the bomb curve to estimate when the sample was collected (which is usually right around when the animal died). For some of the samples, including tusks from elephants that had died in a zoo and in a national park, they knew the animals’ actual ages, and found their estimations were accurate within a year. 

The Nuclear Response

That the technique worked so well in a variety of tissues might make it a useful forensic tool to battle poachers. 

Every year, an estimated 30,000 African elephants are killed illegally for their ivory tusks. With only some 400,000 animals left in the wild, this kind of slaughter could make the species extinct in just a little over a decade. Poaching and the illegal ivory trade are big business, and those trying to stop it are up against organized and well-armed criminal organizations, corrupt government officials and a quirk in the law. 

International treaties have banned the trade of Asian elephant ivory since 1976, and African elephant ivory since 1989, but the laws allow for some loopholes. In some countries, including the United States, any ivory acquired before ’89 is legal to buy and sell. Trying to distinguish legal, pre-ban ivory from poached, post-ban ivory has been incredibly difficult, and ivory traders can move ill-gotten product by claiming that it’s older than it really is. Carbon dating an ivory sample against the bomb curve, though, can date it and reveal how old and how legal it is. It’s science calling BS on poachers and their marketplace enablers. 

Uno’s work complements research done at the University of Washington, which uses DNA and isotope analysis to locate the origin point of ivory. Working out the “when and where” of confiscated ivory (and other animal parts, like rhino horns) can help shut down individual dealers but also identify poaching hot zones and guide decisions about where to spend conservation funds or send armed rangers to protect animals, and it’s all thanks to the atomic crumbs left over from the Cold War. 

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NASA, JPL-Caltech
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Space
It's Official: Uranus Smells Like Farts
NASA, JPL-Caltech
NASA, JPL-Caltech

Poor Uranus: After years of being the butt of many schoolyard jokes, the planet's odor lives up to the unfortunate name. According to a new study by researchers at the University of Oxford and other institutions, published in the journal Nature Astronomy, the upper layer of Uranus's atmosphere consists largely of hydrogen sulfide—the same compound that gives farts their putrid stench.

Scientists have long suspected that the clouds floating over Uranus contained hydrogen sulfide, but the compound's presence wasn't confirmed until recently. Certain gases absorb infrared light from the Sun. By analyzing the infrared light patterns in the images they captured using the Gemini North telescope in Hawaii, astronomers were able to get a clearer picture of Uranus's atmospheric composition.

On top of making farts smelly, hydrogen sulfide is also responsible for giving sewers and rotten eggs their signature stink. But the gas's presence on Uranus has value beyond making scientists giggle: It could unlock secrets about the formation of the solar system. Unlike Uranus (and most likely its fellow ice giant Neptune), the gas giants Saturn and Jupiter show no evidence of hydrogen sulfide in their upper atmospheres. Instead they contain ammonia, the same toxic compound used in some heavy-duty cleaners.

"During our solar system's formation, the balance between nitrogen and sulfur (and hence ammonia and Uranus’s newly detected hydrogen sulfide) was determined by the temperature and location of planet’s formation," research team member Leigh Fletcher, of the University of Leicester, said in a press statement. In other words, the gases in Uranus's atmosphere may be able to tell us where in the solar system the planet formed before it migrated to its current spot.

From far away, Uranus's hydrogen sulfide content marks an exciting discovery, but up close it's a silent but deadly killer. In large enough concentrations, the compound is lethal to humans. But if someone were to walk on Uranus without a spacesuit, that would be the least of their problems: The -300°F temperatures and hydrogen, helium, and methane gases at ground level would be instantly fatal.

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Feeling Anxious? Just a Few Minutes of Meditation Might Help
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iStock

Some say mindfulness meditation can cure anything. It might make you more compassionate. It can fix your procrastination habit. It could ward off germs and improve health. And it may boost your mental health and reduce stress, anxiety, depression, and pain.

New research suggests that for people with anxiety, mindfulness meditation programs could be beneficial after just one session. According to Michigan Technological University physiologist John Durocher, who presented his work during the annual Experimental Biology meeting in San Diego, California on April 23, meditation may be able to reduce the toll anxiety takes on the heart in just one session.

As part of the study, Durocher and his colleagues asked 14 adults with mild to moderate anxiety to participate in an hour-long guided meditation session that encouraged them to focus on their breathing and awareness of their thoughts.

The week before the meditation session, the researchers had measured the participants' cardiovascular health (through data like heart rate and the blood pressure in the aorta). They evaluated those same markers immediately after the session ended, and again an hour later. They also asked the participants how anxious they felt afterward.

Other studies have looked at the benefits of mindfulness after extended periods, but this one suggests that the effects are immediate. The participants showed significant reduction in anxiety after the single session, an effect that lasted up to a week afterward. The session also reduced stress on their arteries. Mindfulness meditation "could help to reduce stress on organs like the brain and kidneys and help prevent conditions such as high blood pressure," Durocher said in a press statement, helping protect the heart against the negative effects of chronic anxiety.

But other researchers have had a more cautious outlook on mindfulness research in general, and especially on studies as small as this one. In a 2017 article in the journal Perspectives on Psychological Science, a group of 15 different experts warned that mindfulness studies aren't always trustworthy. "Misinformation and poor methodology associated with past studies of mindfulness may lead public consumers to be harmed, misled, and disappointed," they wrote.

But one of the reasons that mindfulness can be so easy to hype is that it is such a low-investment, low-risk treatment. Much like dentists still recommend flossing even though there are few studies demonstrating its effectiveness against gum disease, it’s easy to tell people to meditate. It might work, but if it doesn't, it probably won't hurt you. (It should be said that in rare cases, some people do report having very negative experiences with meditation.) Even if studies have yet to show that it can definitively cure whatever ails you, sitting down and clearing your head for a few minutes probably won't hurt.

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