Sunday, December 10, 2017

Recently from Discover

A few cool tidbits from a recent issue of Discover magazine:

From A global state of mind. Vikram Patel, an Indian psychiatrist, has been working for years to document and treat depression and other mental illnesses in developing countries. For 20 years, he's been fighting the perception (on the part of the World Bank and other power brokers) that there is no such thing. He sometimes finds himself speaking to audiences where he's contradicted by white, British psychiatrists who say it's misery and poverty, not depression, that's the culprit. Patel agrees that poverty is important, but there's more to it than that. Global epidemiological research finds:

half of the 10 leading causes of disability were from psychiatric conditions: depression, alcoholism, bipolar diseas, schizophrenia and OCD. Depression alone was the leading cause of disability in every region of the world except sub-Saharan Africa, and outranked the death and disability caused by anemia, heart disease, cancer, malaria and lung disease.
The article contains this fascinating graph:

From the same issue, The peanut plague. I've known about aflatoxin, a naturally occurring killer mold in peanuts, since I was in college (thanks to my brother-in-law, an organic chemist). But somehow I thought it was restricted to peanut butter that wasn't stored properly. I didn't realize it was a huge issue in countries that grow peanuts as a staple crop, including much of Africa.
...public health experts believe that as many as 500 million people [note to self: that's half a billion!] poor people are being slowly poisoned by long-term cumulative exposure to aflatoxins, which can stunt a child's growth, suppress the immune system and lead to liver damage or cancer.
The biomarkers for aflatoxin exposure in developed countries like the U.S., with [so far] strong regulation and testing of crops are almost nonexistent, but when people in developing countries are tested, the rates are more than 90 percent. Scientists are trying to breed a resistant peanut, without success so far, and particular farming practices help, too. But climate change is likely to make the problem worse, since hot, dry conditions toward the end of the plant's growth cycle favor the mold. One current solution is to introduce a nontoxic strain of the mold, which deprives the bad strains of resources, but that costs farmers money to apply, when few of them even believe aflatoxin is real, since its effects take years to show up.

The latest issue of Discover just showed up on my doorstep, containing the top 100 science stories of 2017. The most interesting ones, to my mind, were these three:

Why do humans live to be as old as we do, when women stop reproducing by 50 years old or so, at the latest? There's been writing about the grandmother hypothesis for years, but new research assesses sleep patterns. Studying a band of Hadza hunter-gatherers, scientists studied 220 hours of data and found there were only 18 one-minute increments when all the people in the band were asleep at the same time, and that it was people over 50 who were most likely to be awake at odd hours. "Having a few members of the group awake at all times can protect everyone from predators and other threats." It's called the sentinel hypothesis, and it makes sense that groups of people who had natural sentinels would be more likely to survive over time. (I will try to take comfort from this during my next bout of insomnia.)

You've probably heard of the WEIRD bias in psychological research. If not, the acronym stands for Western, educated, industrialized, rich and democratic, and describes the skewed selection of research subjects in psych research. Here's an example of trying to be a bit more cross-cultural: a recent study in Child Development compared results of the delayed-gratification marshmallow test, using 4-year-old German middle-class children and Cameroonian farming children as subjects. The researchers found 28 percent of the German kids delayed gratification long enough to earn the second treat, while 70 percent of the Cameroonian kids held out for the second marshmallow. (This may be my favorite bit of research ever, since it counters all of the racist messages about Germanic superiority and African lack of self-control.)

Finally, a bit of good tech news: Researchers at MIT and Berkeley have developed a water harvester that, so far, can pull a gallon a water a day from desert air, with energy supplied by a small solar panel. (This sounds like something right out of the classic science fiction novel Dune, where the people on the desert planet Arrakis harvest water using "wind traps.")

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