Thursday, May 01, 2003

Duh! Fish do feel Pain New Scientist -- Fish are capable of experiencing pain. This is the conclusion of researchers who observed rainbow trout behaviour after the animals were given injections that would be painful to people. Other scientists reject their interpretation, but the study could still be used by anti-angling campaigners. The argument over whether fishing is a "blood sport" in the same vein as fox hunting and hare coursing has hinged on whether fish feel pain in a similar way to animals. If they do not, as most researchers currently believe, then the animal welfare argument against angling largely falls apart. Lynne Sneddon at the Roslin Institute, near Edinburgh, Scotland, and her colleagues, took measurements from individual neurons in anaesthetised fish while they poked the fish's heads and applied acid and heat. They identified up to 22 neurons that fire in response to the stimuli. What is more, the firing pattern looked much the same as neurons in humans that transmit the pain message. ... The fish given the nasty chemicals showed clear signs of physiological stress, the researchers found. They took 90 minutes longer to resume feeding and their rate of gill breathing was characteristic of a fish swimming at top speed.  More surprisingly, they displayed very unusual behaviours such as rocking from side to side. Sneddon believes this may be similar to repetitive behaviours sometimes seen in zoo animals. The fish treated with acid also rubbed their lips on the sides and bottom of the tank. (05/01/03) Road Exhaust Damages Sperm New Scientist -- Traffic pollution damages sperm and may reduce fertility in young and middle-aged men, reveals an Italian study of motorway tollgate attendants. The attendants, who spend six hours a day sitting in a roadside booth, showed poorer sperm quality than men of the same age living in the same area but not exposed to the same level of exhaust fumes. Researchers blamed nitrogen oxides and lead for the adverse effects. Although the sperm counts of tollgate workers were normal, their sperm performed less well in tests measuring the ability to reach and penetrate an egg. "The sperm of the study group was more feeble and less active, so it has lower fertility potential," says Michele De Rosa, study lead at the University of Naples. "Our study demonstrates that continuous exposure to traffic pollutants impairs sperm quality in young and middle-aged men." (05/01/03) Ever Seen Mice Reading a Map? New Scientist -- Mice make signposts out of leaves and twigs so that they do not get lost in fields, new research shows. This behaviour surprised Pavel Stopka and David Macdonald, who were studying wood mice captured near their laboratory at the University of Oxford, UK. Primates and some birds are known to use sticks and stones to place markers within their territory. "But no-one would expect mice to be so clever," says Stopka. The excellent navigational abilities of the wood mouse (Apodemus sylvaticus) have been extensively studied, but their way-marking trick had remained undiscovered until now. The latest work suggests the mice move objects to mark sites that interest them, perhaps because they are abundant in food or a quick route back to their burrow. (05/01/03) Where have all the otters gone? New York Times: Environement -- An unusually high number of sea otter deaths this month off the California coast has state and federal wildlife officials worried that the sea otter population, in decline since the mid-1990's, may be experiencing troubles more serious than previously thought. Six dead sea otters have washed ashore in the last several days, bringing to 45 the number of dead or stranded otters in California in April. That is more than double the average number for the month in the last decade, the officials said. "We have had other times when mortality was high, but we attributed it to various things, and it tapered off," said Greg Sanders, the southern sea otter recovery coordinator for the United States Fish and Wildlife Service. "But at this point we are breaking all previous records and we have not found a pattern." State and federal officials are so concerned that on Monday they asked a federal panel of scientists to help determine if an "unusual mortality event" should be declared, an official designation that would make money and other resources available to study the possible causes. So far this year, 92 dead or stranded sea otters have washed ashore in California. The dead included young and old, but perhaps most disturbing for the scientists was that many were considered to be in their prime. Sea otters typically live 15 years. (05/01/03) Feds Enforce Clean Air Act New York Times: Environment -- The Wisconsin Electric Power Company has agreed to spend an estimated $600 million over the next 10 years to reduce pollution at five coal-burning power plants in Wisconsin and Michigan. It is the second electric utility in the last two weeks, after Dominion Virginia Power, to reach an agreement with the government over the Clean Air Act's "new source review" provisions, which govern emission control requirements at aging power plants. Announcing the accord today, the Justice Department and the Environmental Protection Agency said the company, a division of the Wisconsin Energy Corporation, had made millions of dollars in renovations to its plants but had failed to install the pollution controls that "new source review" requires of such renovation. Under the agreement, the company is to reduce its annual air pollution by 105,000 tons by 2013, cutting 74 percent of its acid-rain-causing sulfur dioxide and 67 percent of its smog-inducing nitrogen oxide. In addition, it will pay $3.2 million in fines and spend at least $20 million to test technology to remove mercury from coal. (05/01/03) Genetic Engineering Cancer Resistance CNN Health -- A colony of cancer-resistant mice has been developed by researchers at Wake Forest University. The scientists, who hope the mice will help improve the understanding of cancer in humans, reported their findings in Tuesday's online edition of Proceedings of the National Academy of Sciences. The team led by Dr. Zheng Cui was studying cancer in mice by injecting a virulent form of the disease into test animals. One male mouse did not develop the disease, despite repeated exposure, they reported. When that mouse was bred with other mice, about half the offspring inherited the cancer resistance, indicating a genetic basis for the trait, the team said. (05/01/03) Kniveless Brain Surgery? New York Times: Health -- Without so much as a nick to her scalp, Cheryl Hogarth had major brain surgery on a tumor that had grown to nearly the size of a Ping-Pong ball deep within her brain. Ms. Hogarth, who at 37 was told her malignant tumor was inoperable and given a prognosis of six months to live, went under the Gamma Knife, no-knife surgery that blasts its target with hundreds of high-intensity radiation beams in a single session. There was none of the cutting, bleeding, general anesthesia, ear-to-ear scar or long recovery associated with traditional craniotomy. She went home that evening. Two years after the surgery, Ms. Hogarth, a Sacramento mother of two, is a survivor. She takes chemotherapy to supplement the treatment, and the tumor has not grown. "I now have hope that I will be here to watch my children grow up," she said. Called radiosurgery, this bloodless procedure has grown exponentially in the past several years, accounting for nearly 10 percent of brain operations in 1999. Along the way, however, questions have arisen about the wisdom of using the device, from doctors who question its long-term effects and effectiveness. The number of centers in the United States using the Gamma Knife, made by Elekta, increased from 32 in 1997 to 72 today. In addition, 75 centers use other types of radiosurgery tools, known as the X-Knife, Cyber-Knife and Clinac, machines designed to treat the whole body that have been modified to treat the brain. Though the Gamma Knife has been used in Europe since the 1960's and was approved by the Food and Drug Administration in 1987, improvements in the technology, software and in imaging technology have made it more precise and easier to use. (05/01/03) 8:10:38 AM

© TrustMark 2003 Timothy Wilken. Last update: 6/3/2003; 5:44:40 AM. This theme is based on the SoundWaves (blue) Manila theme.