https://m.kekenet.com/broadcast/201904/582946.shtml
This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
Climate change means springtime's arriving earlier across North America. But the season's onset isn't changing at the same rate across the nation.
"Spring is not advancing as quickly in southern regions as it is in northern regions." Eric Waller, a biogeographer at the U.S. Geological Survey.
He and his team analyzed more than a hundred years of data on when the first leaves and flowers emerge across North America each srpring And they found that although spring has sprung earlier nearly everywhere, in certain wildlife refuges, the season hits extremely early.
And that mismatch could be a problem for migratory birds, who might leave their temperate overwintering grounds down south at the usual time, only to find they've arrived up north too late. "Their food resources might be withering and they might not have as much food available to them. And that could affect their reproduction, their breeding."
The analysis is in the journal PLOS ONE.
The upshot: it may be more difficult than we thought to predict the effects of climate change on migratory birds. But the data might help land managers decide which plots of land to acquire, to augment existing reserves—and in doing so, ensure that even later birds still get the worm.
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.
https://m.kekenet.com/broadcast/201904/582975.shtml
This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
Homo sapiens are nowhere near the fastest runners in the animal kingdom. But what we lack in speed, we make up for in endurance. And we're specially equipped to go the distance. We've got bigger butt muscles than other primates. We lost most of our fur, too, and sprouted lots of sweat glands, to help us cool off.
Scientists believe our endurance running abilities began to appear two to three million years ago, around the time the genus homo came about. And a new study suggests that a mutation in one key gene had something to do with it.
The mutation, in what's called the CMAH gene, altered the types of sugar molecules that decorate the surfaces of every cell in our bodies. Which in turn may have made our muscles less prone to fatigue.
Researchers have now found that mice bred with that same mutation can run longer without tiring, compared to regular mice. The mice with the gene alteration also logged more miles running on their wheels, apparently for fun. And they had more capillaries in their back leg muscles—which would increase the delivery of nutrients and oxygen during endurance exercise.
The complete stats are in the Proceedings of the Royal Society B.
It's unclear if this small genetic tweak endows humans with the same benefits as the mice. But if it does, it could help explain how early humans got a leg up on their competitors. Or, really, two legs.
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.
https://m.kekenet.com/broadcast/201905/584117.shtml
This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
Every year, 20 million tons of salt are dumped on roads and highways across the U.S. to eliminate ice. And airlines spray up to 1,000 gallons of antifreeze on any one plane to de-ice it. But now scientists have come up with what might be a more environmentally friendly alternative.
"We've often heard the expression, 'It's time to fight fire with fire.' Well I think now it's time to fight ice with ice." Jonathan Boreyko studies fluid mechanics at Virginia Tech.
And what he means by that is: if ice growth is inevitable, why not design certain areas of plane wings or roads or HVAC systems specifically to attract ice...to control the chaos, and keep ice-forming moisture away from the rest of the surface? In other words, use ice itself...as antifreeze.
To test the idea, he and his team used lasers to cut tiny grooves into aluminum surfaces. Those grooves, once filled with water and frozen, turned into tiny stripes of ice, which indeed kept the rest of the surface 80 to 90 percent frost-free, even in incredibly humid cold air.
"What's happening is the ice striped areas are just so attractive to the moisture, that it kind of tractor beams all the moisture that's going to the surface towards the striped regions preferentially, such that the intermediate areas, if you design it right, just stay completely dry."
You can find the results and some cool time-lapse videos in the journal ACS Applied Materials & Interfaces.
Boreyko and his team have already patented the tech. If it proves viable after more R&D, it might make our wintertime fight against frost a lot more environmentally friendly.
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.