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For small island nations, marine plastic cleanup is prohibitively expensive

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Sept. 10 (UPI) — Island nations like the Seychelles are uniquely vulnerable to the barrage of plastic pollution pouring into the world’s oceans, and research published Thursday in the journal Scientific Reports suggests the cleanup bill is prohibitively expensive.

“The Indian Ocean is fringed with countries that have poor waste management infrastructure,” lead researcher April Burt told UPI in an email.

“Other studies have shown that most of the marine plastic litter in the oceans is coming from ten rivers, the majority of which are in Asia,” said Burt, an ecologist and graduate student at Oxford University in Britain.

Cleanup efforts on the Seychelles revealed an abundance of plastic shoes, mostly flip flops, as well as netting and line from commercial fishing operations.

To estimate the financial burden the barrage of plastic places on small island nations like the Seychelles, Burt and her research partners first calculated the effort to clean a small portion of the coast.

Scientists determined a 2019 cleanup, comprising 980 hours of work by 12 volunteers over the course of five weeks, cost a total of $224,538.

Next, researchers set out to estimate the total amount of plastic found strewn across Aldabra, the Seychelles’ outer islands and the world’s second-largest coral atoll.

“We conducted a series of transects at 20 locations along the coast in each of the main coastal habitat types: beach, vegetation and limestone karst,” Burt said. “For each transect we separated and weighed the litter found into six main categories and used this to extrapolate up to estimate total litter accumulated.”

The six litter categories included: consumer plastic items, such as toothbrushes and cigarette lighters; plastic packaging material like plastic bottles; fishing-related items, such as buoys and netting; plastic footwear; small, unidentified plastic fragments; and other materials like glass.

“Our research shows that the main source was from the industrial tuna fisheries — this industry exports tuna worldwide,” Burt said.

When researchers added it all up, they determined it would require 18,000 hours of labor and cost $4.68 million to clean up all the plastic pollution found along the Aldabra coast.

Because much of the plastic pollution that makes its way to the shores of smaller island nations is coming from bigger, richer nations and extractive industries, the researchers suggest that wealthier countries help pay for the cleanup.

“We hope our findings will be used by local and regional governments to call out the need for international funding for dealing with the issue of marine plastic litter,” Burt said.

Burt also said more must be done to ensure the commercial fishing industry can’t continue to dump waste with impunity.

“The huge costs involved in removal are way beyond the financial capacity of local organizations and governments who are responsible for these island ecosystems,” she said.



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Unusual Aussie spider builds one-of-a-kind nest with super strong silk

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Oct. 19 (UPI) — As far scientists know, no other spider builds a nest quite like the Australian basket-web spider.

Thanks to a new study, published Monday in the journal Scientific Reports, scientists now know how the spider’s lobster pot-like web keeps its structure without the help of vegetation.

“This silk retains its rigidity, allowing a rather exquisite silken basket or deadly ant trap,” study co-author Mark Elgar, a professor of evolutionary biology at the University of Melbourne, said in a news release.

For the study, researchers closely examined the chemical and structural composition of the spider’s silk. Their analysis showed the silk is similar to the kind of silks used by other spiders to construct egg sacs.

“Our discovery may provide insights into the evolution of foraging webs,” said Elgar. “It is widely thought that silk foraging webs, including the magnificent orb-webs, evolved from the habit of producing silk to protect egg cases. Perhaps the basket-web is an extension of the protective egg case and represents a rare contemporary example of an evolutionary ancestral process.”

The lobster pot trap of the basket-web spider, found only in Australia, measures just less than a half-inch in diameter and a bit more than a half-inch in length. It features a series of cross-linked threads of varying diameters.

Researchers were able to analyze the web and its robust fibers using high-resolution imaging technologies at ANSTO’s Australian Synchrotron facilities.

“Nature has created a complex structure that, at first glance, resembles industrially produced composites,” said study co-author Thomas Scheibel, professor of biomaterials at the University of Bayreuth in Germany.

“Further investigations have, however, shown that they are chemically different components and their respective properties together result in the thread’s extreme elasticity and toughness, thus creating a high degree of robustness,” Scheibel said. “With today’s composite materials, on the other hand, it is mainly the fibers embedded in the matrix that establish the particular properties required, such as high stability.”

The research suggests a new genetic material is key to the robustness of the novel silk — a material that could be synthesized at scale for industrial applications.

Scientists estimate, however, that additional research is needed to isolate the material and realize its potential.

“There is increasing recognition that solutions to many of the complex challenges and puzzles we face today can be found from biological systems,” Elgar said.

“This so-called ‘Bioinspiration’ draws on some 3.8 billion years of natural selection honing biological forms, processes and systems. The potential insights from that diversity of life, about which we still know rather little, is staggering,” Elgar said.



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‘Happy ending effect’ impairs future decision-making, study says

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Oct. 19 (UPI) — Humans rely on their experiences to inform their decision making process, but new research suggests the “happy ending effect” prevents humans from accurately gauging the true value of an experience.

Previous studies have shown that humans overemphasize the ending of an experience when assessing its value. For example, a spell of bad weather on the last couple days of a vacation can leave travelers with a feeling of disappointment, spoiling their impression of the otherwise enjoyable trip.

New research, published Monday in the Journal of Neuroscience, suggests the phenomenon can interfere with a person’s ability to make good decisions.

“When you’re deciding where to go for dinner, for example, you think about where you’ve had a good meal in the past,” lead study author Martin Vestergaard said in a news release.

“But your memory of whether that meal was good isn’t always reliable — our brain values the final few moments of the experience more highly than the rest of it. If we can’t control our in-built attraction to happy endings, then we can’t trust our choices to serve our best interests,” said Vestergaard, a neuroscientist at the University of Cambridge in Britain.

For the study, researchers had participants select between two streams of coins falling into a bucket in quick succession. Larger coins were higher in value.

One stream was greater in value but ended with a succession of smaller coins, while the other less-valuable stream ended with a run of bigger coins. Participants consistently — and incorrectly — selected the stream that ended with larger coins.

Researchers used brain activity recordings and computational models to better understand the phenomenon. The analysis confirmed that the experience valuation process was encoded in the amygdala.

The study’s authors suggest it’s important for the human brain to observe the upward or downward trajectory of an experience — but the process can also impair a person’s ability to accurately evaluate an overall experience.

“Our attraction to the quality of the final moment of an experience is exploited by politicians seeking re-election; they will always try to appear strong and successful toward the end of their time in office,” said Vestergaard. “If you fall for this trick, and disregard historical incompetence and failure, then you might end up re-electing an unfit politician.

“Sometimes it’s worth taking the time to stop and think,” he said. “Taking a more analytical approach to complement your intuitive judgement can help ensure you’re making a rational decision.”



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Plague transmission rates increased from the Black Death to the Great Plague

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Oct. 19 (UPI) — From the 14th to the 19th centuries, Europe and Asia were struck by successive waves of the plague. New research — published Monday in the journal PNAS — suggests that over the course of the pandemic, from the Black Death of 1348 to the Great Plague of 1665, transmission rates increased four-fold.

In recent years, genomic analysis has offered scientists a variety of insights into the nature of bubonic plagues that decimated much of Europe and Asia during the Late Middle Ages, but details related to disease transmission mode and dynamics have been hard to come by.

Plague is caused by the bacterium Yersinia pestis, which can be transmitted via flea bites, the typical route for bubonic plague, or directly from human to human, called pneumonic plague.

“Both types of transmission can occur during a given epidemic, but which type of transmission seems most likely in various times and places, and why, is often debated,” lead study author David Earn, a researcher in mathematical epidemiology at McMaster University in Canada, told UPI in an email.

By studying a variety of historical, demographic and epidemiological data, Earn and his colleagues were able to show that transmission steadily increased over the course of the epidemics that struck London between the 14th and 19th centuries.

The data also showed that pneumonic transmission could not have been the primary mode of transmission during the 14th century in London.

Scientists relied on three main sources of data: weekly all-cause mortality totals from parish registers, beginning in 1538, when deaths were first registered; weekly mortality from plague, recorded in the London Bills of Mortality; and last wills and testaments, dated to the day, running from 1340 to 1680.

Researchers used the mortality data to estimate transmission rates of each successive epidemic. The research team also ran models to estimate mortality totals had the early waves been driven primarily by human-to-human transmission.

“In this scenario of purely pneumonic transmission, we found that at most 15 recent of the population would have died from plague,” Earn said. “But estimates of the mortality toll during the Black Death in 1348 are at least 30 percent of the population. This inconsistency makes purely pneumonic transmission in the 14th century implausible.”

Earn and his colleagues suspect both climate and shifting population densities played a role in accelerating transmission rates during the later waves of the plague.

“Evidence has accumulated over the last 15 years or so that humidity affects influenza transmission, and it is reasonable to imagine that climate might affect plague transmission,” Earn said.

In followup studies, researchers plan to investigate the effects of climate, population density, social structure and genetic changes on the transmissibility of plague and the primary transmission mode during the 16th and 17th centuries.



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