Making the most of end-of-life and robot-microbe hybrids

Graphic provides an overview of options being explored for building and controlling a biohybrid microrobot, including different microbes, carriers and external controls.

Cell meets robot in hybrid microbots

Researchers are developing microbe-propelled tiny bots to deliver drugs, target cancer or do other work in the body

Photograph of an elderly woman lying in bed. Standing and sitting around her are family members, two of them holding her hands. A hospice aide and a bottle of lotion are seen at the foot of the bed.

Going gentle

A sociologist explains how to get the most out of the final months of life

Around the web
Searching for a hidden city 
Sac Balam, as journalist Lizzie Wade writes, was a city meant to be hidden. As the Spanish pillaged what’s now Mexico and other areas of Central and South America, local people faced long odds of their culture surviving intact. Sac Balam (which means “white jaguar”) was a refuge for its inhabitants, the Lacandon Maya, as they attempted to hide in the jungle and remain free to carry on their ways. The Spanish finally found the city and forcibly relocated its inhabitants, but in the centuries since it has eluded researchers. In her piece for Science, Wade details the often-harrowing journey she takes with a Winthrop University team (flesh-ripping foliage and blood-sucking ticks ensue) looking for the city’s remote ruins. There are scant clues, but the quest is a reward unto itself.   
Corralling a potential carcinogen 
The browning process behind cooking starchy or sugary foods known to chemists as the Maillard reaction imparts delicious flavors and aromas, but has an unfortunate downside: It also produces acrylamide, which has been linked to cancer in laboratory animals. That may be bad news for lovers of potato foodstuffs, many grain-based baked goods and even coffee, whose roasting process involves the Maillard reaction. Out of caution, many in the food industry are looking for ways to lower acrylamide levels in foods. As Melody Bomgardner writes at Chemical & Engineering News, a bevy of approaches are under investigation — from genetic engineering to taking cues from deep-sea microbes and more — all in a quest to bring the levels down to ALARA, or “as low as reasonably achievable.”
Knowable Magazine dove into acrylamide when the state of California was debating whether to put a carcinogen warning label on coffee due to the presence of acrylamide. As we noted, doses of acrylamide fed to lab animals in cancer studies is high, “the equivalent of a 150-pound person drinking 11,000 to 136,500 eight-ounce cups of coffee per day,” and thus the actual carcinogenic effect in humans may be overstated. Indeed, California’s Office of Administrative Law decided in June against carrying warning labels as coffee had yet to be linked to increased cancer risk in any study.
All puffed up and ready to go
It seems impossible, but the 120-odd species making up the pufferfish section of the Tetraodontidae family tree might be even weirder than they look. This is no small feat for creatures that can make their spine-covered bodies expand exponentially by ingesting water, not to mention the potent toxin some species harbor for would-be predators. But then you learn about their mouths … and their mating habits … and more, thanks to Susan Milius at Science News, with a brief but fun pufferfish overview. One species, for instance, the Japanese grass pufferfish, beaches itself en masse for a mating dance that’s usually so gender-imbalanced that hundreds of male pufferfish are competing for just one female. As she releases her egg, the males release their sperm, and the whole scene is often rinsed away by an incoming wave (hopefully after a few of those eggs get fertilized). Other weird rituals are also noted, including some involving the fish’s strange teeth, which are beaked like a bird’s but must be continuously worn down like a rodent’s. 
Selected scholarly reviews
The journals from Annual Reviews, the nonprofit publisher of Knowable Magazine, offer rich, expert-written takes on a broad array of subjects from medicine to materials research. Here’s what caught our attention this week. 
The MMR vaccine and autism: a primer
This year’s alarming outbreaks of measles — the CDC has recorded more than 1,200 cases of the highly contagious infection, which can cause seizures, brain swelling and death — is a testament to some communities’ deep fear of vaccines, in particular the MMR vaccine and its spurious link to autism. For an authoritative overview of the facts and timeline of all that has led us to today, read Frank DeStefano and Tom Shimabukuro’s paper in the Annual Review of Virology. The authors, both of the US Centers for Disease Control and Prevention, detail the initial, shoddy and now-retracted 1998 study (which was looking for a link between the vaccine and inflammatory bowel disease), and go over the many, many studies since that have found no link. Also discussed: How health-care providers, medical organizations and others might bring those who are fearful of vaccines back into the fold. As the authors note: “Everything should be done to avoid a scenario where widespread resurgence of measles, with its attendant suffering, disability, and death, becomes the motivating force for renewed acceptance of MMR vaccination.”
Special Article Collection from Annual Reviews: Biomedical Breakthroughs
Art & science
Show your stripes
A series of vertical bars in various shades of blue and red, representing temperature changes. As the stripes move rightward, they grow redder — indicating climate change related temperature increases.
As autumn descends in the Northern Hemisphere, it’s perhaps inevitable that some politicians will revive the argument that cooler weather means global warming is a hoax. Of course, reams of data, such as those used to generate these warming stripes, say otherwise. Created by climate scientist Ed Hawkins, the simple, beautiful (and somewhat terrifying) visualizations reveal long-term trends in temperature data: The color of each stripe represents the temperature of a single year, going back to the earliest available data for the selected location. Shown here are temperatures for the globe from 1850 to 2018; at Show Your Stripes, you can drill down to view data by country and US state. Earlier this summer, Climate Central teamed up with meteorologists around the world to share the message embedded in the stripes, which adorned ties, cufflinks, coffee cups and even a tram. Keep an eye out for the stripes as your local season changes.
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Knowable Magazine explores the real-world significance of scholarly work through a journalistic lens. A digital magazine from Annual Reviews.
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