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U.S. is one of the world’s top contributors to coastal plastic pollution

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Oct. 30 (UPI) — The coastline of the United States is relatively clean compared to other parts of the world, but new research suggests the U.S. is one of the world’s top contributors to coastal plastic pollution.

The U.S. exports large amounts of plastic waste. Previous studies have ignored plastic scrap exports, offering the impression that the United States was effectively collecting, disposing and recycling its plastic waste, researchers have said.

According to a new study, published Friday in the journal Science Advances, more than half of the plastic waste collected for recycling in the U.S. — 1.99 million metric tons of 3.91 million metric tons — is shipped out of the country.

Researchers found the vast majority of exported plastic scraps, 88 percent, ends up in countries that are struggling to adequately manage plastic waste. Environmental scientists determined at least 1 million metric tons of plastic waste exported by the U.S. ends up polluting environments abroad every year.

“For years, so much of the plastic we have put into the blue bin has been exported for recycling to countries that struggle to manage their own waste, let alone the vast amounts delivered from the United States,” study lead author Kara Lavender Law said in a news release.

“And when you consider how much of our plastic waste isn’t actually recyclable because it is low-value, contaminated or difficult to process, it’s not surprising that a lot of it ends up polluting the environment,” said Law, a research professor of oceanography at the Sea Education Association.

Researchers also determined that a small but not inconsequential amount of plastic waste collected in the U.S. each year — 2 to 3 percent — is littered or illegally dumped.

After accounting for exported waste, as well as littered or illegally dumped domestic waste, researchers determined the U.S. was responsible for 2.25 million metric tons of plastic pollution in 2016, the last year for which pollution data is readily available.

Roughly two-thirds of the plastic polluted by the U.S. ends up in coastal environs, according to the new study — making the U.S. the world’s third largest producer of coastal plastic pollution.

Despite accounting for just 4 percent of the world’s population, the U.S. is responsible for 17 percent of the world’s coastal plastic pollution.

“The United States generates the most plastic waste of any other country in the world, but rather than looking the problem in the eye, we have outsourced it to developing countries and become a top contributor to the ocean plastics crisis,” said study co-author Nick Mallos.

“The solution has to start at home. We need to create less, by cutting out unnecessary single-use plastics; we need to create better, by developing innovative new ways to package and deliver goods; and where plastics are inevitable, we need to drastically improve our recycling rates,” said Mallos, senior director of the Ocean Conservancy’s Trash Free Seas program.

The researchers suggest their findings should serve as a wakeup call for U.S. policy makers and industry leaders to take responsibility for the nation’s plastic pollution footprint.

“For some time, it has been cheaper for the United States to ship its recyclables abroad rather than handle them here at home, but that has come at great cost to our environment,” said study co-author Natalie Starr.

“We need to change the math by investing in recycling technologies and collection programs, as well as accelerating research and development to improve the performance and drive down the costs of more sustainable plastics and packaging alternatives to address the current challenge,” said Starr, principal at DSM Environmental Services.



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Scientists program robot swarm to count penguins

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Oct. 28 (UPI) — Penguins occupy ecosystems increasingly vulnerable to climate change. Tracking their abundance and distribution is vital to the project of tracking global warming’s ecological effects — but counting penguins is difficult work.

To make the task of tallying the size of penguin colonies a bit easier, researchers recruited the assistance of not one robot, but a whole swarm of bots.

“The idea actually grew out of a conversation at my sister-in-law’s wedding,” Mac Schwager, an assistant professor of aeronautics and astronautics at Stanford University, told UPI in an email. “I met our co-author Annie Schmidt at the wedding, and learned that she studies penguin populations in Antarctica, and one of their key challenges was counting the penguins.”

“I told her I worked with autonomous groups of drones that could be used to take images for counting the penguins,” Schwager said. “At that point, it was clear that we had a great research synergy.”

Researchers typically use a single drone to conduct aerial surveys of penguin colonies, but the process is slow and requires a lot of time, effort and skill from the drone pilot.

In collaboration with Schmidt and her team of biologists, Schwager and Stanford grad student Kunal Shah programmed a swarm of drones to autonomously survey penguin colonies.

The team of scientists described their novel solution in a new paper published Wednesday in the journal Science Robotics.

“Our main technical innovation is our path planning algorithm, the computer program that decides where each drone should go and when,” Schwager said. “Existing methods typically plan paths like a lawnmower, or a vacuum cleaner, going back and forth over the survey area.”

“It turns out, other paths can be much more effect, in the sense that they can take the same images while requiring less back-tracking, and while making sure that the drone is close enough to the base camp to make it back safely with the remaining battery life.”

Previously, it took scientists three days to survey Antarctic penguin colonies using a solitary, hand-piloted drone. The robot swarm programmed by Schwager and his colleagues completed surveys in just two to three hours.

Time is precious in Antarctica, where animals are often on the move and weather can quickly take a turn for the worse. But speed isn’t the swarm’s only advantage. The self-piloted robots also offer reliability.

“If one drone fails, the other drones can take up the slack and still finish the survey,” Schwager said.

For now, Schwager’s swarm of drones only take pictures. The counting is done back at base after the survey has been completed and the photographs downloaded onto computers. But in the future, Schwager said the drones could use artificial intelligence to count penguins as they go.

Schwager has previously programmed robotic swarms to track the movement of people and cars on the ground in order to analyze pedestrian and vehicular traffic patterns, and he thinks similar algorithms could be adopted to track animal movements.

“The system could also be used to survey forests and other landscapes for wildfire risk, a problem that is very close to home right now for us at Stanford,” he said. “We could also use the drones to survey construction sites, mining sites, agricultural fields, to assess damage after a natural disaster, or to help find lost hikers.”

Biologists and study co-authors Schmidt and Grant Ballard are currently testing the drone aerial survey system in Antarctica. Meanwhile, Schwager and his colleagues at Stanford continue to make tweaks to the system to help the drones make better in-flight decisions and avoid collisions with birds or drones that have gone astray.

“We are passionate about using teams of autonomous drones to help us to understand and take care of the natural environment around us,” Schwager said.



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Fight judges favor aggression over skill, study shows

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Oct. 28 (UPI) — Often to the chagrin of fans and competitors, wrestling matches, boxing bouts, mixed martial arts and other types of combat competitions are frequently decided by judges.

That’s bad news for competitors that rely more on skill than vigor. New research suggests judges are more likely to award victory to aggressive fighters than skilled fighters, all else being equal.

For the study, published this week in the journal Biology Letters, researchers analyzed data collected from 550 men’s and women’s mixed martial arts contests organized by the Ultimate Fighting Championship.

The data included the percentage of strikes that landed firmly and accurately, a measure of skill, as well as the number of strikes attempted per second, a measure of vigor or aggression.

Regardless of the match conclusion, whether decided by knockout or judges’ decision, the data showed the victor was the more vigorous fighter. However, the correlation between vigor and victory was strongest for matches decided by the scores of the judges.

Fighting skillfully wasn’t entirely discounted. The data showed addition of skill enhanced the advantage of vigor, but the research showed vigor was the most important factor for fights decided by the judges.

“MMA is a fast paced sport and one of the suggestions from our research would be that judges may find vigor easier to assess than skill,” lead author Sarah Lane, postdoctoral research fellow at the University of Plymouth, said in a news release. “That, in turn, leads them to overvalue it when making their decisions, especially in longer fights where one fighter tires more quickly and the disparity in vigor is easier to spot.”

“The advance of technology such as instant replays could potentially counter this, but until they are employed more regularly rate of attack is likely to remain the most important performance trait for victory by decision,” Lane said.

The research was funded by the Biotechnology and Biological Sciences Research Council, which supports studies focused on the role of skill in animal contests.

Most of Lane’s time is spent studying hermit crab fighting, but the authors of the latest paper suggest their analysis of human fights could have implications for understanding physical competitions among animals.

There aren’t typically knockouts in fights between rival animals. Often, males joust and tussle to demonstrate their physical dominance to would be rivals and mates. Like in boxing, a competitor’s performance is subjective.

“Human combat sports provide a unique scenario in which to explore how performance traits such as skill and vigor are perceived, both by participants and observers,” said study co-author Mark Briffa.

“However, because of the obvious communication issues, very little is known about the accuracy with which fighting animals more widely judge the abilities of their rivals,” said Briffa, a professor of animal behavior at Plymouth.



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Graphene-based memory resistors could pave the way for brain-based computing

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Oct. 29 (UPI) — Researchers have created a new computer component capable of toggling between 16 possible memory states — the kind of computing versatility provided by brain synapses.

The new component, called a graphene field effect transistor, described Thursday in the journal Nature Communications, could pave the way for advances in brain-inspired computing.

Modern computers are exclusively digital, featuring two states: on-off or zero and one. Engineers at Penn State University are working to build a computer that replicates the brain’s analog nature, capable of hosting many different states.

If a digital computer’s information processing components work like a light switch, toggling only between on and off, then an analog computer is like a light dimmer.

Scientists have been investigating the potential of brain-based computing for decades, but analog computers have been overshadowed by the advances in traditional computing power. However, the rise of big data and smart devices like self-driving cars has highlighted the need for more computing efficiency.

“We have powerful computers, no doubt about that, the problem is you have to store the memory in one place and do the computing somewhere else,” lead researcher Saptarshi Das, an assistant professor of engineering science and mechanics at Penn State, said in a news release.

All the movement of information required by the bifurcation of memory to logic in modern computers puts a strain on speed. It also requires more spaces. Das and his research partners estimate that their graphene field effect transistor can help eliminate this bottleneck.

“We are creating artificial neural networks, which seek to emulate the energy and area efficiencies of the brain,” said study first author Thomas Shranghamer.

“The brain is so compact it can fit on top of your shoulders, whereas a modern supercomputer takes up a space the size of two or three tennis courts,” said Shranghamer, a doctoral student in the Das group.

Brain synapses can be quickly reconfigured to create a variety of neural network patterns. Likewise, the new graphene field effect transistor, formed by a one-atomic-thick layer of carbon atoms, can be used to control 16 possible memory states.

Researchers were able to reconfigure the transistor, effectively toggling between memory states, by applying a brief electric field to the graphene layer.

“What we have shown is that we can control a large number of memory states with precision using simple graphene field effect transistors,” Das said.

Das and his research partners are now looking to work with semiconductor companies to attempt to scale-up the production of the new technology.



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