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| (Note that this photo was not taken in Charlestown, where this is an illegal act.) |
By Linda Felaco
The paradox of global
warming. Now you’ve got an answer next time there’s a heavy snowstorm and
some wag says “So much for global warming.” Turns out hotter summers can in
fact cause colder, snowier winters. According to Judah Cohen, a climate modeler
at Atmospheric and Environmental Research in Lexington, Massachusetts, average
temperatures in the Arctic have been rising nearly twice as fast as in the rest
of the world, while winters have grown
colder and more extreme in southern Canada, the eastern
United States, and much of northern Eurasia.
In a recent report in Environmental Research Letters, Cohen and his colleagues demonstrate how
global warming drives
regional cooling. As
the Arctic has warmed, melting sea ice has increased the amount of open water
in the Arctic Ocean and thus evaporation, which increases moisture in the
overlying atmosphere, the researchers say. Previous studies have linked hotter
summers to increased cloudiness over the ocean during the following autumn.
That, in turn, triggers increased snow cover in Siberia as winter approaches. The
researchers found that Siberian snow cover in October has the greatest effect on
climate in subsequent months, because it strengthens a high-pressure system that
steers frigid air southward throughout the winter. Incorporating this
information into climate models could lead to more accurate winter weather
forecasts.
Man’s best friend …
and physician? Two recent genetic studies in dogs may provide clues to
human disease. A skin disease in humans and golden
retrievers may have a common genetic origin as well. A new study of golden
retriever DNA shows that the
same gene is mutated in both dogs and people suffering from one of a cluster of
rare diseases that cause the skin to form scaly patches and that can
sometimes be fatal, offering a much-needed clue to the disease’s origins. The
study shows the power of using dog genetics to learn more about human diseases,
Heidi Parker, a geneticist at the Dog Genome Project of the National Human Genome
Research Institute in Bethesda, Maryland, told ScienceNOW.
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| The same gene that helps your dog to sit and stay helps your toddler to do the same. |
And it turns out that in a series of behavioral
tests of German shepherds, researchers found that the dogs with a shortened
version of a gene implicated in attention deficit disorder in humans had the
most trouble controlling their impulses, regardless of their sex, age, or
training, whereas the dogs with long versions of the gene passed the impulse-control
tests with flying colors. The study, reported in the current issue of PLoS
ONE, may not only help breeders identify hyperactive dogs but could also prove
useful in studies of ADHD in humans.
Wonder if this is how
Newt courted Callista. Male great bowerbirds spend most of their time
building elaborate nests called bowers and surrounding them with rocks, sticks,
shells, and bones to attract members of the opposite sex. The male arranges
these trinkets, or “gesso,” so that the largest ones lie farthest from where
the female stands such that from her perspective, the objects all appear to be
the same size.
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| Tiffany's for bowerbirds. (Photo by JJ Harrison (http://www.noodlesnacks.com/) |
Turns out that the
better the male manages to create this illusion, the better his chances of
mating with a female. The illusion may
hold the female’s attention for longer than a poorly arranged gesso, researchers
suggest online today in Science, giving the male time to mate with her.
Fill ‘er up at the
beach? Seaweed could be an ideal source of biofuel because unlike switchgrass
and wood, it requires no land, fresh water, or fertilizer, and it has no lignin,
which makes it harder to extract the sugars that ferment into ethanol. But about
a third of the sugars in seaweed take the form of alginate, which industrial
microbes can’t convert into ethanol.
In work published
this week in Science, researchers
describe a strain of Escherichia coli
that they have genetically engineered to break down and ferment alginate and
all the other major sugars in seaweed into ethanol. Although it’s unclear
whether enough seaweed could be harvested to make a dent in petroleum use and lower
carbon emissions, experts say it’s a step in the right direction.