News this Week

Science  20 Nov 2015:
Vol. 350, Issue 6263, pp. 892

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  1. This week's section

    Brazil mud could wreak years of havoc

    Deadly slow-motion mudslide destroys town and poisons water supplies.


    As a result of two mining dams that collapsed on 12 November, an enormous wake of toxic mud has engulfed and destroyed the Brazilian town of Bento Rodrigues, and the damage continues to spread down the Doce River. The mudslide has forced 500 people to relocate and has already claimed nine lives; 19 others are listed as missing. The mud has also contaminated the river with metals such as zinc, arsenic, mercury, and copper, poisoning its potential as a water source. Toxic conditions have wiped out aquatic life hundreds of kilometers downriver, and experts say that biodiversity will take an irreparable hit. By early next week, the mud is expected to reach the Atlantic. Samarco Mineração SA manages and operates the mines and dams; on 12 November, the Brazilian government fined the company $66 million, but that number could increase. As the deadly sludge continues to creep along, towns up to 330 kilometers away are preparing for potential disaster, shipping in extra water supplies for schools and hospitals.

    Fish parasite once a jellyfish

    Myxozoans are stripped-down jellyfish.


    Tiny fish parasites called myxozoans were once considered protists, a group including amoebae and slime mold. But Paulyn Cartwright, an evolutionary biologist at the University of Kansas, Lawrence, and other scientists suspected these parasites might instead be kin to jellyfish. Myxozoan cells contain a capsule with a barbed filament that they use to latch onto the host—it looks suspiciously like the stinging cells of a jellyfish. This week, in the Proceedings of the National Academy of Sciences, Cartwright and her team report a comparative survey of the genomes of two myxozoans, true jellyfish and Polypodium hydriformea, a parasite with a jellyfishlike life stage. The study confirms that myxozoans are cnidarians, the genus that includes jellyfish, which lost both cells and DNA. Their genomes, one-fortieth the size of their jellyfish kin, lack genes for multicellular development and differentiation, as well as those for cell-to-cell communication. The next step, Cartwright says, is to figure out how a complex, multicellular jellyfish could evolve into a few-celled parasite.

    44%—Drop in global deaths of women due to complications in pregnancy and childbirth from 1990 to 2015, according to a 12 November World Health Organization report.

    Around the world


    Russian scientists form nonprofit

    Hoping to a fill a void left by the closure in July of Dynasty, Russia's only private research funder, a group of scientists is planning to launch a new foundation. Dynasty spent $30 million from 2002 to 2015 on seed money for young Russian scientists and on competitions for science teachers, science festivals, and public lectures by world-class researchers. However, because it received funds from outside of Russia, it ran afoul of Russia's “foreign agents” law and was forced to wind up its activities in July. The new nonprofit, called Evolution, has only managed to raise tens of thousands of dollars so far—and has accordingly set modest ambitions. Initially it will focus on science popularization, including publishing Russian science authors and translating science books into Russian.

    Milan, Italy

    Expo 2015 site to host research

    The site of Expo 2015, this year's science-themed Universal Exhibition in Milan, Italy, may get a second life as an international hot spot for science and technology. The Universal Exhibition, whose motto was “Feeding the Planet, Energy for Life,” closed on 31 October after drawing more than 21 million visitors over 6 months. The Italian government plans to shell out €150 million annually for 10 years to redevelop the 100-hectare area as a research campus for as many as 1600 researchers. The new science hub, dubbed the Human Technopole, would focus on genomics, big data, aging, and nutrition.

    Parma, Italy

    Report: no herbicide-cancer link

    The common herbicide glyphosate is unlikely to increase the risk of cancer, at least in its pure form, according to a 12 November assessment from the European Food Safety Authority (EFSA). A report earlier this year by the World Health Organization's International Agency for Research on Cancer (IARC) classified glyphosate as “probably carcinogenic to humans.” But the IARC report included epidemiological studies of commercially available herbicides, such as Roundup, that have multiple ingredients. The EFSA report focused on studies that involved pure glyphosate. It also included several un published studies that IARC did not use. EFSA says more studies are needed to evaluate whether commercially available formulations of glyphosate are safe. The EFSA evaluation did set a recommended maximum short-term limit for glyphosate intake: 0.5 milligrams per kilogram of body weight. The new report will influence the European Union's decision on whether to keep the compound on its list of approved chemical substances; that approval expires at the end of 2015.


    Scientists protest work conditions

    Frustrated scientists took to the streets in Chile last week to protest low research spending, frail science institutions, poor career prospects, and what they see as the government's overall disregard for science. On 12 November, 2500 researchers, technicians, and students marched to La Moneda, the presidential palace in Santiago, to deliver an open letter that expressed their “desolation” with government decisions that “will plunge the country into ignorance and poverty.” The signatories demanded that the government set up a science ministry and promote science as a part of the “national culture.” The protest came on the heels of the resignation on 29 October of Francisco Brieva as head of Chile's research funding agency, the National Commission for Scientific and Technological Research; Brieva told Chile's El Mercurio newspaper on 1 November that the country's bureaucracy stifled his plans to kick-start public investment in science, and that he hadn't received a paycheck in 6 months.


    Last known Ebola case released

    A newborn baby who recovered from Ebola was released from a treatment center here on 16 November. The infant, whose mother died of the disease, is the country's last known case of Ebola. The last people under quarantine after possible exposure to the virus were released 2 days earlier. Guinea now starts a 42-day countdown—twice the incubation period for the virus—before it can be officially declared Ebola-free. Sierra Leone was declared free of the virus on 7 November and Liberia has been officially Ebola-free since September. The world's largest outbreak of Ebola, which sickened more than 28,000 and killed more than 11,000, started in Guinea in December 2013.


    Trained pigeons ID cancer

    Pigeons peck to identify cancerous tissue.


    Can birds spot cancer? Like humans, they have excellent visual systems—and they are cheaper to train than medical students. A study this week in PLOS ONE put pigeons to the test. Researchers trained the birds to examine microscope images of breast tissue on a computer touchscreen; the birds pecked colored buttons to distinguish cancerous from healthy tissue. If the birds correctly identified cancer, they got a food pellet. In a matter of days, the pigeons' performance improved to better than random; by the end of a month, their accuracy rose to as high as 80%. But the real power came from the flock: By combining identifications from different birds, the accuracy rose to 99%—on par with trained human experts, and better than a computer doing automatic image analysis. So are trained pigeons the future of cancer diagnosis? “I doubt it,” says lead author Richard Levenson, a pathologist and technologist at the University of California, Davis. “I suspect that computers will get there first.”