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| For more information on these science news and feature story tips, please contact the public information officer at the end of each item at (703) 292-8070. Editor: Bill Noxon
Contents of this Tipsheet:
BACTERIA TELL TIMEScientists are rethinking what they know about bacteria: it turns out that the organisms tell time. New studies of a laboratory bacterium show that the organism passes on a biological clock, even while it divides to produce new generations of offspring, according to Susan Golden, a Texas A&M; University molecular biologist. Golden's research at the College Station campus is funded by the National Science Foundation's (NSF) division of molecular and cellular biosciences. "Recent results suggest that a lot of cells have their own clocks--cells that we might not expect to have them," says Golden. The biologist used two different methods to measure activity governed by the circadian--or clock--cycle, while cells of a bacterium known as cyanobacteria were in the midst of dividing to reproduce. Golden found that even if the organism produced four new generations of offspring during one circadian cycle, each new generation's biological functions continued on the same schedule as that of the original parent organism. "This was a big surprise," says Golden, "but we now know that it's possible for cells to divide, and to have their 'daughter' cells remember where they are in the parent's clock at that time." Eventually, understanding how circadian rhythms work could lead to improved treatments in humans for depression and other psychological illnesses. Scientists also predict there could be more effective chemotherapy for cancer and improved timing in drug delivery for other diseases. [Cheryl Dybas]
SCIENTISTS FIND CLUE ON HOW DEFORESTATION AFFECTS GLOBAL CARBON CYCLESScientists affiliated with the NSF's H.J. Andrews Experimental Forest Long-Term Ecological Research site in Oregon may have found part of the answer for how deforestation affects global carbon cycles. Balancing earth's carbon budget is no easy task, says researcher Mark Harmon, because such estimates usually don't account for all amounts of carbon stored in major forests. But Harmon and his colleagues have developed a modeling strategy that uses satellite maps of forest harvesting activity and vegetation cover to derive more accurate estimates of the amount of carbon in a forest environment. A major finding of the study is that the Pacific Northwest region appears to have been a significant source of carbon to the atmosphere from 1971 to 1992. This is an extension of Harmon's previous work, which indicated that this region has been a source of carbon input to the atmosphere for the last century. Another finding is that the present analysis indicates that a fairly large proportion of the regrowing forest is not coming back as quickly as scientists had expected. "This may be caused by an unanticipated delay in regeneration," Harmon says. Researchers are particularly concerned about this phenomenon, which is currently being studied through field work and remote sensing techniques. [Cheryl Dybas]
NEW AGREEMENT ASSIGNS AIR NATIONAL GUARD TO FLY ALL U.S. SKI PLANES IN ANTARCTICAA Memorandum of Agreement between the National Science Foundation (NSF) and the Department of Defense (DOD) designates the Air National Guard to provide air logistics support to the U.S. Antarctic Program, which is run by NSF. Signed on January 21, the agreement reflects the shift in Hercules LC-130 heavy airlift (ski-equipped aircraft) from the Naval Support Force Antarctica and the Naval Antarctic Development Squadron-6 to the New York Air National Guard's 109th Airlift Wing in Schenectady, New York. This airlift function will be formally transferred from the Navy to the U.S. Air Force/Air National Guard in March, 1998. The agreement is one of a series of steps in the U.S. Navy's withdrawal from its support role in the U.S. Antarctic Program, and the replacement of its services by DOD and by civilian companies contracted to NSF. [Lynn Simarski]
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