An anonymous reader quotes a report from CBC News: It's rare that cancerous tumors can spread from one individual to another. But a genetic study suggests that's what's happening with melanoma tumors among catfish in Quebec and the northeastern U.S. The discovery represents the first known transmissible cancer in fish and one of very few transmissible cancers ever found, reported the study published in the journal Nature on Wednesday. Julie Dragon, co-leader of the new study, noted that only three other transmissible cancers have ever been identified so far -- in Tasmanian devils, dogs and shellfish. "These conditions are incredibly rare in nature," she said. "So something has to be happening to allow this to happen." Anglers in Lake Memphremagog, which spans the border between Quebec and Vermont, first reported catching brown bullhead catfish with strange black spots and lumps in 2012. They turned out to be melanoma skin cancer tumors. (Humans can also get this kind of cancer.) Now, about a third of the brown bullheads living in the lake have them. It's not clear how sick the fish become. In some cases, the cancer spreads to other organs, such as the brain or liver. But many fish with lesions seem relatively healthy and some older fish even have them, suggesting they can live with the disease for a time. Because of the sudden appearance of the black lesions in Lake Memphremagog the year after a huge flood caused by post-tropical storm Irene, locals worried they were caused by carcinogens washed into the lake by floodwaters. Tests for carcinogens haven't been conclusive, although a study published in May found higher concentrations of seven metals, including zinc and the carcinogen arsenic, in the skin of fish with the tumors. Researchers suspect the tumors may spread among adult fish during spawning, when crowded fish rub against one another and may be punctured by their spines. "They... swim all over each other and we think it's possible that they poke each other and cells can get into other fish that way," Dragon said, though transmission has not yet been demonstrated.

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An anonymous reader quotes a report from The Guardian: They say you catch more flies with honey than vinegar. But when it comes to tackling a tricky task, researchers have found that getting angry can also be a powerful motivator. The experiments suggest people who are angry perform better on a set of challenging tasks than those who are emotionally neutral. "These findings demonstrate that anger increases effort toward attaining a desired goal, frequently resulting in greater success," said Dr Heather Lench, the first author of the study. The study, published in the Journal of Personality and Social Psychology (PDF), details how researchers at Texas A&M University conducted experiments involving more than 1,000 people, and analyzed survey data from more than 1,400 people, to explore the possible impact of anger on people in various circumstances. In one experiment, students were shown images previously found to elicit anger, desire, amusement, sadness or no particular emotion at all. Participants were subsequently asked to solve a series of anagrams. The results reveal that for a challenging set of anagrams, those who were angry did better than those in the other possible emotional states -- although no difference was seen for easy anagrams. The researchers say one explanation could be down to a link between anger and greater persistence, with the team finding those who were angry spent more time on the difficult set of anagrams. In another experiment, participants who were angry did better at dodging flags in a skiing video game than those who were neutral or sad, and were on a par with those who felt amusement or desire. "This pattern could indicate that general physical arousal had a benefit for game scores, as this would be greater in anger, amused, and desire conditions compared to the sad and neutral conditions," the researchers write. However, no such differences in performance was found when it came to an easier video game.

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