ريتشارد دوكنز's Blog, page 569

What Is the Deal With Synthetic Marijuana?

Photo credit: Spencer Platt/Getty Images

By Leon Neyfakh

If you’re confused by synthetic marijuana, then a series of recent news stories about the drug probably didn’t clear things up. First, the Boston Globe reported that New England Patriots defensive end Chandler Jones “had a bad reaction to a substance he put into his body” and walked to a nearby police station to get help. That substance, the Globe later explained, was synthetic marijuana. Then last week, police in Washington state reported that another NFL player, Seattle Seahawks fullback Derrick Coleman, admitted to smoking synthetic weed in October before getting into a hit-and-run car accident. After the accident, witnesses described Coleman as acting “delirious and aggravated.”

Off the sports pages, you might have seen a story about a group of senior citizens in Pennsylvania who got arrested for running a synthetic marijuana trafficking ring worth more than $1.5 million. Or perhaps you saw the one about a pair of brothers in Milwaukee, ages 12 and 13, ending up in the hospital after smoking some fake pot and having a violent reaction that included foaming at the mouth, “throwing up white mucus,” “talking funny,” and shaking.

These are only the latest data points showing the rise of synthetic marijuana as a staple of recreational drug use in America. Against the backdrop of softening attitudes toward actual marijuana, synthetic weed has attracted a strange coalition of users, including athletes, curious teenagers, and desperate homeless people. Here’s a primer on the drug whose ambiguous legal status and unpredictable side effects have turned it into a bleak cultural phenomenon.

What is synthetic marijuana, and how is it different from normal weed?

The most important fact to understand about synthetic marijuana is that it isn’t just one thing. It’s more like a category of things, a family of man-made chemicals that have one major characteristic in common: They interact with the same cell receptors in the brain as THC, the active ingredient in natural cannabis. In theory, someone could ingest these chemicals in any number of ways, but manufacturers play up the association between their products and traditional marijuana by spraying their chemicals onto diced-up dry plant matter that can be sold in baggies and smoked.

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Is This the Biggest Spiral Galaxy in the Universe?

Photo credit: Galaz et al., 2016

By Phil Plait

From the cream floating in your coffee cup to hurricanes to galaxies themselves, spirals form on a vast range of scales. They may be for different reasons (coffee and hurricanes have faster rotation in the center, winding up the arms, whereas galaxies form spirals from a more subtle and complex effect that acts like an interstellar traffic jam), but when you have stuff that spins, spirals can arise naturally.

But how big a spiral can you get? Our Milky Way galaxy is pretty beefy, one of the bigger spiral galaxies in the Universe. It’s roughly 100,000 light-years across, or a quintillion kilometers. That’s a lot of kilometers.

Don’t go bragging to your friends just yet though. It turns out spirals can get bigger. Way, way bigger.

The galaxy pictured at the top of this post is called Malin 1. It’s faint; so dim it was only discovered in 1986, and was the first discovered in a class of galaxies called low-surface brightness spiral galaxies. Most spirals are pretty bright and easy to see, but LSBs are much fainter. Despite that, they can grow to huge sizes.

I’ve known about Malin 1 for a while, but it hadn’t really registered with me one way or another. That changed instantly when I saw a new paper about it, which was featured on the American Astronomical Society’s Nova site, where notable discoveries are highlighted.

I saw the photo of it and nodded in admiration; it’s a very pretty and interesting spiral. But then I saw the distance, and my brain did a double take. Malin 1 is 1.2 billion light-years away.

“Wait,” my brain said, shaking itself. “What? That can’t be right!”

But it is: 1.2 billion light-years is a tremendous distance. If it’s that far, and that big in the image, it must be huge. Freaking huge.

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Republicans Prefer Blunt Talk About Islamic Extremism, Democrats Favor Caution

Photo credit: Pew Research Center

By Pew Research Center

Half of Americans say the next president should be careful not to criticize Islam as a whole when speaking about Islamic extremists, while four-in-ten want the next president to speak bluntly about Islamic extremists even if the statements are critical of Islam as a whole. A new Pew Research Center survey finds that blunt talk is preferred by two-thirds of Republicans and those who lean toward the Republican Party (65%), while seven-in-ten Democrats and independents who lean Democratic express the opposite view, saying the next president should speak carefully about Islamic extremism so as not to criticize Islam as a whole.

The study also shows that many Americans think a substantial segment of the U.S. Muslim population is anti-American. While four-in-ten adults say “just a few” Muslims in the country are anti-American (or that none are), roughly half of the public believes that at least “some” U.S. Muslims are anti-American, including 11% who say “most” or “almost all” U.S. Muslims are anti-American and 14% who think “about half” the U.S. Muslim population is anti-American.

The new findings come on the heels of a separate Pew Research Center survey conducted in December 2015, which found that 46% of Americans think Islam is more likely than other religions to encourage violence and that a similar share (49%) say they are “very concerned” about the rise of Islamic extremism in the U.S.

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Unicef Report Finds Female Genital Cutting to Be Common in Indonesia

Photo credit: Ed Wray

By Pam Belluck and Joe Cochrane

Female genital cutting has always been seen as an ancient ritual practiced in Africa and to a lesser extent in the Middle East, but a new global assessment documents for the first time that it is widespread in one of the most populous countries in Asia: Indonesia, where almost half the women are estimated to have undergone it.

There has long been anecdotal evidence of the practice there, but the United Nations Children’s Fund estimated Thursday that 60 million women and girls there have been cut based on national survey data collected by the Indonesian government. The addition of Indonesia is largely responsible for raising the global tally of women and girls who have undergone the practice to 200 million from 130 million, and the number of countries where it is concentrated to 30 from 29.

“We knew the practice existed but we didn’t have a sense of the scope,” said Claudia Cappa, a statistics specialist for Unicef, which released the report. She said the new data from Indonesia showed that cutting was not just “an African problem.”

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DNA Study of First Ancient African Genome Flawed, Researchers Report

Photo credit: Stephanie Mitchell/Harvard University

By Carl Zimmer

When scientists first started to figure out how to extract DNA from ancient skeletons, their success was met with astonishment. One minute, scientists were fishing Richard III’s genes from his royal bones, and the next they were showing off DNA retrieved from 5,000-year-old Incan mummies.

The idea that DNA could survive for thousands of years — let alone be reassembled into an entire genome — seemed little short of miraculous.

Despite the field’s rapid advances in recent years, though, ancient DNA is still hard to find and hard to make sense of. Potential errors lurk around every corner. Even little oversights can cause big headaches.

Andrea Manica, a geneticist at the University of Cambridge, appreciates this fact all too well. A head-turning study by his team turned out to have a fundamental flaw that erased some of its most provocative conclusions.

In October, Dr. Manica and his colleagues reconstructed the first ancient human genome ever found in Africa, retrieved from the skeleton of a man who lived in Ethiopia 4,500 years ago.

Ancient DNA experts were delighted, because the genome may provide clues about African history that other kinds of evidence — broken pottery shards, for example, or scraps of ancient manuscripts — cannot.

“It’s an amazing, amazing, unique, special, incredible, first-of-its-kind data set,” David Reich, a geneticist at Harvard Medical School who was not involved in the study, said in an interview.

After Dr. Manica and his colleagues published their results, Dr. Reich and Pontus Skoglund, another geneticist at Harvard, requested the original data. They wanted to use it in their own studies of ancient human populations.

Dr. Reich and Dr. Skoglund reanalyzed the findings — but did not reach the same conclusions.

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A Genetic Switch Could Turn Obesity On Or Off

Photo credit: Wikimedia Commons

By Claire Maldarelli

Science does not yet really understand the underlying causes of obesity. A new research study, though, may have uncovered a remarkable mechanism–essentially a biological on/off switch for obesity. The work, which was published yesterday in the journal Cell, could help researchers develop better therapies to combat obesity.

Their idea is based on epigenetics–the concept that things like your height, weight, and other physical traits are based on not just what genes you inherit, but also the interaction of those genes with the environment you live in. Depending on that interaction, certain genes can turn on or off other genes–one of the main reasons why identical twins sometimes don’t look so identical.

The researchers focused on a particular gene, named Trim28, which they found affected weight in mice–making them either lean or obese, but nothing in between. To understand Trim28 in humans, they studied 13 sets of identical twins in which one twin was obese and the other was lean. The researchers found less activity of Trim28 in the obese twins’ cells compared to their lean twin.

Scientists already knew that Trim28 can affect other genes that influence weight, so the researchers concluded that Trim28 may act as an epigenetic switch to either turn obesity on or off by suppressing or activating a set of genes that control weight.

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Reflections on the habitability of Earth

Photo credit: NASA

By Peter Kelley

We know the Earth is habitable because—well, here we are. But would it look like a good candidate for life from hundreds of light-years away?

Good, but perhaps not great, according to astronomer Rory Barnes of the University of Washington-based Virtual Planetary Laboratory. It’s a question, among many others, that he and co-authors asked in a recent paper.

Barnes, a research assistant professor of astronomy, colleagues are drawing up a “habitability index for transiting planets” that ranks exoplanets to help prioritize the search for life.

Astronomers spot possible exoplanets, or those beyond the solar system, not through direct observation but by the dimming of light that happens when the worlds pass in front of, or “transit” their host star. Many factors go into judging a world’s possible habitability, including the amount of energy it gets from its star, the distance and radius of its orbital path and the behavior of its neighbor planets. Spectrometry is used to estimate the mass and radius of the host star, from which astronomers can the estimate the size of the planet itself.

They use this data to create a model of a planet—”an idea of a planet,” Barnes said, which is then compared with information about other worlds. “And you basically try and sort out, do I think that could reasonably be a planet that’s habitable?”

But validating, or confirming planets is methodical, time-consuming work, and access to the big telescopes needed is expensive. The habitability index helps astronomers rank and prioritize planets to help determine which are worthy of closer study.

Managing these myriad calculations, the index gives the Earth, if observed from afar as we now observe faraway planets, about an 82 percent chance of being right for life.

But wait—only 82 percent?

Why wouldn’t the Earth—the single example of a life-hosting world in all our experience—score a perfect, 100 percent rating?

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Making Science Teaching More Than ‘A Backup Plan’

Photo credit: Theo Stroomer for NPR

By Anya Kamenetz

“Squat! Squat! Squat! Higher! Faster!”

In the basement of the Duane Physics and Astrophysics building at the University of Colorado Boulder, a science demonstration is going on, but it looks more like a vaudeville act.

One by one, students balance precariously on a rotating platform. Then they are handed what looks like a spinning bicycle wheel, holding it by two handles that stick out from either side of what would be the hub of the wheel. When you flip the wheel over, like a pizza, your body starts rotating in the opposite direction.

The principle at work is called angular momentum, explains Katie Dudley: “You can move or stop yourself by changing what you do to the wheel.”

Dudley is a blonde 20-year-old junior with glasses, an aerospace engineering major. She’s in charge of today’s session, tutoring a roomful of students who are her own age or even a bit older. She’s a learning assistant — an undergraduate trained and paid to help teach fellow students.

Most science and engineering classes around the country are a lot less interactive, a lot more intimidating, and daresay it, a lot less fun than this one. CU Boulder has started a movement to improve the quality of science education around the country, not only on campuses but in K-12 classrooms. And the LAs, as they’re called, are at the center of this work.

The efforts here began with professors like Steven Pollock, who team-teaches the Physics 1110 course where Dudley is an LA. As we sit upstairs in his office, he tells me that about 15 years ago, he switched his research specialty from nuclear physics to the teaching of physics.

“I just sort of saw myself in 2000 looking forward 20 or 30 years to retirement,” he explains. “I could either have learned a little bit more about the strange quark content of the proton, or how people learn physics and how to teach it better. And it seemed like that was way more important to the world.”

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Race Is a Social Construct, Scientists Argue

Photo credit: R. Gino Santa Maria/Shutterstock

By Megan Gannon

More than 100 years ago, American sociologist W.E.B. Du Bois was concerned that race was being used as a biological explanation for what he understood to be social and cultural differences between different populations of people. He spoke out against the idea of “white” and “black” as discrete groups, claiming that these distinctions ignored the scope of human diversity.

Science would favor Du Bois. Today, the mainstream belief among scientists is that race is a social construct without biological meaning. And yet, you might still open a study on genetics in a major scientific journal and find categories like “white” and “black” being used as biological variables.

In an article published today (Feb. 4) in the journal Science, four scholars say racial categories are weak proxies for genetic diversity and need to be phased out. [Unraveling the Human Genome: 6 Molecular Milestones]

They’ve called on the U.S. National Academies of Sciences, Engineering and Medicine to put together a panel of experts across the biological and social sciences to come up with ways for researchers to shift away from the racial concept in genetics research.

“It’s a concept we think is too crude to provide useful information, it’s a concept that has social meaning that interferes in the scientific understanding of human genetic diversity and it’s a concept that we are not the first to call upon moving away from,” said Michael Yudell, a professor of public health at Drexel University in Philadelphia.

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Boosting Life Span By Clearing Out Cellular Clutter

Photo credit: Philippe Merle/AFP/Getty Images

By Nell Greenfieldboyce

Mice were much healthier and lived about 25 percent longer when scientists killed off a certain kind of cell that accumulates in the body with age.

What’s more, the mice didn’t seem to suffer any ill effects from losing their so-called senescent cells.

These are cells that have stopped dividing, though not necessarily because the cells themselves are old. “It’s a normal cell that experienced an unusual amount of stress, and it decided to stop dividing,” says Jan van Deursen, who studies senescent cells at the Mayo Clinic College of Medicine in Rochester, Minn.

Older creatures have a lot more of these cells than young ‘uns. And even though the cells aren’t dividing, they do keep busy — they secrete a mixture of chemicals that can trigger inflammation, which seems to be involved in just about every major age-related disease.

So van Deursen and his colleagues wanted to know: What would happen if you simply got rid of senescent cells? That’s tough to do in humans, but possible in mice.

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