Gizmorama - February 1, 2016

Good Morning,

Electrified concrete might be the answer to help keep snow off the streets. That sounds like a great idea that couldn't possibly go really wrong. Do I worry too much?

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin

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*-- Electrified concrete paves way for snow-melting streets --*
LINCOLN, Neb. - Researchers at the University of Nebraska are testing a new type of concrete that could make clearing snow-covered streets a bit easier. The concrete is designed to carry an electric current, helping it melt snow without the help of a salt truck or plow.

The conductive concrete is made by adding carbon particles and steel shavings to a traditional asphalt mix. The additives make up just 20 percent of the mixture. Once hardened, the composite material can carry a current just strong enough to melt snow and ice while remaining safe to the human touch.

Currently, the concrete occupies a 200-square-foot space outside Nebraska's Peter Kiewit Institute, where scientists are monitoring its performance during the Midwest's winter months.

"When you use conducting concrete, the entire concrete heats up," lead researcher Chris Tuan, a professor of civil engineering at Nebraska, told National Geographic. "There is no cold area."

The research is supported by funding from the FAA, which is considering employing the concrete in airport tarmacs.

"To my surprise, they don't want to use it for the runways," Tuan said in a press release. "What they need is the tarmac around the gated areas cleared, because they have so many carts to unload -- luggage service, food service, trash service, fuel service -- that all need to get into those areas."

"They said that if we can heat that kind of tarmac, then there would be (far fewer) weather-related delays," Tuan said. "We're very optimistic."

Though it wouldn't be cost-effective to pave entire roads with the new conductive concrete, the material could be use in strategic locations -- bridges, high-traffic intersections, exit ramps, parking decks, driveways and sidewalks.

Sending a current through a few hundred slabs or concrete in a bridge costs much less than a truckload of salt and de-icing chemicals. Those chemicals can also prove corrosive, encouraging potholes that cost time and money to fix.

Tuan hopes to eventually install sensors that would make the concrete and its current automated, allowing an even more hands-off approach to de-icing. But it may be some time before the concrete is put to good use by municipalities.

While city governments and contractors may be wary of electric concrete, Tuan is a true believer and an early adopter.

"I have a patio in my backyard that is made of conductive concrete," he said. "So I'm practicing what I preach."


*-- Researchers confirm key component of evolutionary theory --*
GLASGOW, Scotland - The "Meselson effect" is a key aspect of evolutionary theory. It predicts that pairs of chromosomes in asexual organisms diverge and evolve independently, becoming increasingly dissimilar over time.

The effect is named after accomplished geneticist Matthew Stanley Meselson, who first conceived of the phenomenon some 20 years ago, but until now, scientists haven't been able to offer concrete evidence of the effect.

Researchers at the University of Glasgow successfully demonstrated the effect in a parasite known as Trypanosoma brucei gambiense, or T.b. gambiense. It's the first time the effect has been proven in a living organism. The parasite causes sleeping sickness in humans.

Scientists analyzed the genomes of 85 different parasite samples collected from Guinea, Cote d'Ivoire and Cameroon between 1952 and 2004.

The analysis -- detailed in the journal eLife -- revealed divergent chromosomes, devoid of genetic recombination. The research suggests the parasite is a subspecies evolved from a single individual no longer than 10,000 years ago.

"It was around this time that livestock farming was developing in West Africa, allowing the parasite, which was originally an animal organism, to 'jump' from one species to the other via the Tsetse fly," lead study author Willie Weir said in a press release.

"Since then, mutations have built up and the lack of sexual recombination in T.b. gambiense means that the two chromosomes in each pair have evolved independently of each other, demonstrating the Meselson effect," Weir added.

Researchers say the parasite's inability to recombine genes hinders its ability to adapt and develop resistance to multiple drugs.

Sex is the predominant form of reproduction for a reason. It helps organisms persist, enables lineages to continue.

"An organism's genetic blueprint is encoded in DNA packaged within structures called chromosomes. Most organisms have two copies of each chromosome and, through sexual reproduction, the DNA within the chromosomes can recombine randomly, in effect shuffling the deck of DNA cards," Weir explained. "This process generates genetic diversity and, through natural selection, undesirable combinations and mutations are eliminated from the population, promoting long-term survival of the species."

The Meselson effect predicts that abstinence can only work for so long, and that asexual organisms should eventually become extinct. Eventually, the parasite that causes sleeping sickness should be no more. But researchers aren't yet able to predict when the end will come.

The latest research suggests the parasite uses a technique known as gene conversion to maintain genetic health. The parasite is able to identify gene mutations and replace them by copying and pasting healthy sequences from the chromosome's partner.

Researchers say more research is necessary to determine the long-term consequences of an organism's reliance on genetic conversion.

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