SciTech Briefs

Penguins are bio archives of climate change

At the American Geophysical Union’s 2018 Ocean Sciences Meeting on Feb. 12, scientists reported that penguins feathers and eggshells preserve chemical fingerprints of climate and ecological changes.

Penguin tissues store the changes in the food that they consume, which can be interpreted by looking at their chemical composition. For example, krill and fish have different nitrogen isotope proportions, which, when consumed by penguins, is reflected in the composition of their tissues.

Overfishing and climate change has led to some dramatic changes in the penguin lifestyle. Kelton McMahon, an oceanic ecogeochemist at the University of Rhode Island in Kingston is a member of this study along with his team developed tools to distinguish between changes in penguins’ diet and other climate change related changes. He says, “Penguins are excellent bio archives of this [environmental] change.

“This 80-year record is just part of a much broader record of change,” McMahon adds. Now, the team intends to study older penguin artifacts. Some excavations have unearthed penguin eggshells that are over 100,000 years old.

Source: Science News

Brains think about moving while detecting rhythms

In a study published online in the Journal of Cognitive Neuroscience on Jan. 18, researchers found that if the region of the brain that planned movement is disabled, the brain has trouble detecting changes in rhythms.

The human brain understands rhythm by making predictions about the spaces between between beats, and essentially guessing when the next beat will fall. This helps us interpret repeated sounds, like music, and this prediction making is a part of the brain system called relative timing.

Jessica Ross, a coauthor on the study and a neuroscience graduate student at the University of California Merced, along with the team of researchers who worked on the study, rendered the areas of the brain responsible for movement - the posterior parietal cortex and the supplementary motor area - temporarily unable to function by applying a magnetic pulse to that area.

The researchers tested 25 adults, and found that while the participants were able to identify the rhythms fine without the supplementary motor area, they couldn’t differentiate between rhythms without the the posterior parietal cortex.

“Music is basically sounds that have a structure in time,” says Sundeep Teki, a neuroscientist at the University of Oxford. According to Teki, studies like this one help illuminate how our brains understand music.

Source: Science News

Household chemicals pollute air as much as cars

A recent study shows that many common household chemicals contribute to urban air pollution at levels comparable to vehicle exhaust. This category includes not just household cleaners, but also products like nail polish remover, printer ink and even soap.

“The things I use in the morning to get ready for work are comparable to emissions that come out of the tailpipe of my car,” says lead author Brian McDonald, an air-pollution researcher at the US National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado. “I think that’s what surprises a lot of people.”
Like exhaust from cars and trucks, household chemicals contain volatile organic compounds. When they evaporate, these compounds contribute to ozone and smog.

Despite increased regulation on vehicle emissions over the past four to five decades, many US cities, like Los Angeles, struggle to comply with air cleanliness standards. This study helps explain why: vehicle exhaust is a huge contributor to urban air pollution, but it isn’t the only contributor.

The research team used a variety of data, including existing datasets and both indoor and outdoor air samples, to support their hypothesis. “We had to collect an overwhelming amount of evidence to say that these sources are important,” says McDonald.

Source: Nature

Tree rings in southwestern U.S. point to increased fire risk

Scientists at the US Geological Survey (USGS) study tree rings to understand the history of a region’s climate so they can predict the risk of future wildfires.
When a tree is cut horizontally, the cross-section reveals layers of concentric circles.

It’s common knowledge that one ring grows each year; but a ring can reveal more than just age: it contains details about what the environmental conditions were like during that year.

According to the patterns in this natural historical data, USGS scientists claim that New Mexico might experience a devastating wildfire season this year. The area of concern is the Sangre de Cristo Mountains outside Santa Fe. According to the tree ring data, the region hasn’t experienced a wildfire in around a century, which means that the forest constitutes a huge amount of potential fuel, USGS scientist Ellis Margolis explains. “We’re sitting on this powder keg,” he says.

By studying the tree ring histories, Margolis determined that the biggest wildfires occur in very dry winters that occur after two or three years of winters with a lot of precipitation. After wet winters in 2016 and 2017, New Mexico is experiencing a very dry winter right now. “The lack of snow is scary,” says Margolis. “We’re set up for a big fire year if things don’t change dramatically.”

Source: Nature