[NEWS] Seven science links

• Climate change is playing a major role in the wildfires of California. Are we now in the Fire Age? Global News considers.
• The new normal of the Arctic Ocean is to be ice-free. Global News reports.
• Plants first reached land through unexpected horizontal gene transfers. CBC reports.
• Zebra mussels have made it to the Lake of the Woods. Global News reports.
• An artificial leaf that turns carbon dioxide into usable fuel is a remarkable technology. Universe Today reports.
• Earth once hosted nine human species; now it has one. What happened? National Pot considers.
• Thanks to better medical care and preventative measures, people have longer healthy lifespans than ever before. Global News reports.

[NEWS] Five links: Tumblr, Lough Foyle, giant snails, Gillian Genser, Tell el-Hammam

• VICE’s Motherboard suggests that the crackdown on anything NSFW on Tumblr can be blamed on the expanding power of the Apple Store, one element of its indiscriminate sanitization of the Internet.
• Garrett Carr at 1843 Magazine takes a look at Lough Foyle, the northern Irish bay that will become part of a hard border come Brexit.
• Giant African snails, Sarah Laskow suggests at Atlas Obscura, have spread so widely in recent centuries thanks to humanity that the presence of their shells might well be a noticeable marker of the Anthropocene.
• At Toronto Life, sculptor Gillian Genser tells the heartbreaking story of how she was poisoned by the heavy metals contained in the mussel shells that she used as raw materials for a sculpture.
• Evan Gough at Universe Today reports the claim of some archaeologists that, 3700 years ago, the city of Tell el-Hammam was destroyed by a meteor that exploded above it with the force of a large nuclear warhead. Inspiration for Sodom and Gomorrah?

[LINK] “Mussels’ Sticky Secretions Make for Super-Strong Adhesives”

Wired‘s Chelsea Leu reports on something that, frankly, should not surprise people who know the only way you can open a mussel is to boil it.

Some sea creatures float lazily in the ocean, letting the currents waft them where they may. Mussels are not those creatures. They live in tidal areas, and their lives are a churning series of unpredictable events: submerged in the wash one tidal cycle, baking in the sun the next. Not to mention all those waves, constantly threatening to dash them to bits. So they’ve evolved to cling very, very tightly to rocks, ships, piers—anything, really—like their lives depend on it, because they sort of do.

The secret’s in their secretions. “Mussels take a bunch of protein, lay it down on a surface, and crosslink it all together,” says Jonathan Wilker, a chemist at Purdue University. Specifically, mussels use a rare amino acid called dihydroxyphenylalanine, or the more-pronounceable DOPA. (It’s related to dopamine, the neurotransmitter.) DOPA is unusual, because it enables materials to be both cohesive and adhesive—that is, the materials can stick to themselves and other surfaces. The balance of the two forces determines whether something makes good glue, and DOPA manages both. “It’s very efficient,” Wilker says.

And DOPA is extremely easy to tinker with, which is great for scientists looking to design a new adhesive, says Bruce P. Lee, a biomedical engineer at Michigan Tech. Its structure allows it to play nice with a whole range of different chemistries, which means it can stick to practically anything—metal, body tissue, even Teflon. So scientists make chemicals that mimic DOPA’s structure (harming no mussels in the process), and tweak it to suit their own ends, whether that’s a biodegradeable glue, or something that can set while underwater, or something stronger than superglue.