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Stories of Modern Science ... from UPI

By ALEX CUKAN, UPI Science Writer   |   Jan. 14, 2002 at 4:40 AM   |   Comments


FORAGING STRATEGIES OF RIGHT WHALES

University of Rhode Island researchers have estimated that zooplankton patches where right whales feed must reach concentrations on the order of tens to hundreds of thousands per cubic meter in order for the whales to obtain a net energy benefit from feeding. Right whales feed on zooplankton, primarily copepods, tiny drifting animals approximately the size of a small grain of rice. Because of this specialized diet, right whales must locate feeding areas where copepods are concentrated into high-density patches, writes oceanographer Robert D. Kenney in the Journal of Cetacean Research and Management. "It is clearly of interest to determine how right whales locate the dense zooplankton patches within their feeding grounds," says Kenney. "It may provide insight into how and why right whales become entangled in fishing gear and how they may cope with potential changes in prey distribution caused by climate change." Right whales use a number of strategies to locate feeding grounds and prey concentrations. Some have to do with long-distance seasonal migrations over weeks and months, and others depend on minute-by-minute selection of the optimal prey patches within a particular feeding area.


IS ANTARCTIC IS WARMING OR COOLING?

An analysis of 35 years of climate data shows most of Antarctica is cooling down, not warming up, according to researchers at the University of Illinois in Chicago. This conclusion conflicts with "greenhouse" climate models that predict the largest temperature rises at the poles, but other researchers dispute the team¹s findings, New Scientist reports. "We are not saying that global warming is not going on," says Peter Doran. "But something is going on at the poles that is not predicted by the climate models." Doran¹s team studied air temperature measurements taken across Antarctica over the past 35 years. It also analyzed a highly detailed set of temperature measurements taken between 1986 and 2000 in the McMurdo Dry Valleys, a small ice-free region at the edge of the continent, south of New Zealand. "Here, the average air temperature has cooled by 0.7°C per decade," Doran says. "Data combined from numerous recording stations across the continent point to a similar trend over the last 35 years." Most climate researchers in Antarctica are based on the Antarctic Peninsula, on the other side of the planet, below South America. "Whether or not there has been significant cooling or not is open to a great deal of argument," says David Vaughan at the British Antarctic Survey. "Records covering the last 50 years show beyond doubt that the continent is warming," Vaughan says.


'FEED A COLD, STARVE A FEVER' MAY BE GOOD ADVICE

There may be some wisdom in the traditional maxim, "feed a cold, starve a fever," according to researchers at the Academic Medical Center in Amsterdam. The balance of two chemicals that regulate the relevant branches of the immune system seem to shift markedly after a meal, preliminary research suggests. "There appears to be a parallel between our data and the old saying," say Gijs van den Brink, a cell biologist. He found that eating and fasting cause brief fluctuations in the amount of two chemical messengers called cytokines in healthy volunteers. "Why this happens is not clear," says van den Brink. "After a meal, the average level of the cytokine gamma interferon in the blood of six volunteers increased by 450 percent." Interferon stimulates the body's defense against chronic infections by helping to trigger the release of killer white blood cells, which destroy infected cells. Starved volunteers, on the other hand, had low interferon levels but far higher concentrations of another cytokine called interleukin-4. Interleukin-4 is associated with the production of antibodies, the protein molecules that form the front line defense against acute infections. "Fevers are often associated with swift-acting infections, whereas colds could refer to less serious, longer-lasting ailments," says van den Brink.


CULTURE AFFECTS ATTITUDES TOWARD DEPRESSION

A research team in Royal Holloway's Department of Psychology at the University of London in England examined attitudes towards alcohol and suicide among United Kingdom Protestants and Jews, to discover tolerance levels for depression. Previous research found that the prevalence of depression is lower among Protestants than among Jews, and among men than among women. It had been suggested that this is because Protestant men escape depression by drinking or killing themselves. The study tested this hypothesis by examining alcohol use, alcohol beliefs, reported suicide attempts and suicide beliefs within the two groups. "Protestants reported heavier drinking than Jews, generally had more favorable attitudes towards alcohol use and were more liberal towards alcoholics," says Kate Loewenthal, the study co-author. "Among the Jewish participants, the main concerns were loss of control, revulsion at drunken behavior and fear of addiction." Protestants, however, believed that drinking is normal, socially acceptable, relaxing and a pleasant escape from stress. The study supports the idea that Jewish men are reluctant to use alcohol as an escape from depression and, in parallel, were found to report higher levels of tolerance of depression than their Protestant counterparts.


(For more information, about WHALES, call 401 874-2116; about DEPRESSION, call 44-1793-413122.)

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