Scientists

Liftoff of the Astro-1 space shuttle mission has unofficially been postponed until at least Dec. 1 because of persistent fuel leaks on Columbia, raising fears among mission scientists that the astronomy project may be further postponed into next year or even canceled.Disappointed Astro-1 scientists -- including teams from the Johns Hopkins University and Goddard Space Flight Center -- were told yesterday that NASA had reshuffled the mission to third in line, behind the launch of the Ulysses solar probe aboard Discovery and a military mission on Atlantis.

Scientists studying a meteorite that fell to Earth from Mars have identified organic compounds and certain minerals that they conclude "are evidence for primitive life on early Mars."The discovery of the first organic molecules ever seen in a Martian rock is being hailed as startling and compelling evidence that at least microbial life existed on Mars long ago, when the planet was warmer and wetter.The molecules found in the rock, which left Mars some 15 million years ago, are being described as the fossil trace of past biological activity.

Scientists at the Environmental Protection Agency have recommended a ban on the sale of one of the most poisonous pesticides used in U.S. agriculture, and the agency promised a quick decision on the recommendation yesterday.Since 1966, the pesticide, ethyl parathion (pronounced pair-a-THI-on), has poisoned more than 650 field workers in the United States, including at least 100 who died, according to studies by the EPA, the California Department of Food and Agriculture and other state agriculture departments.

In laboratories across America, scientists work feverishly to create the perfect frozen pizza.Slathering pizza pies with a new wonder topping would ensure )) the crisp crusts they crave, a topping that would keep the tomato sauce from seeping into the bread dough prior to their arranged marriage at 425 degrees.That wonder topping: plastic.Not your basic petroleum-based Saran Wrap, but edible films made from corn, wheat, soybeans and other crops. Food wrap that melts in your mouth, adds protein and makes you feel good about the environment every time you bite into your jumbo supreme pizza.

Dr. Gerald M. Rosen may be a leader in the study of microscopic particles called free radicals, but he committed scientific fraud by using identical graphs of the molecules' action to illustrate reports of different experiments, an expert in the field testified yesterday.Dr. Gary R. Buettner of the University of Iowa testified in Baltimore County Circuit Court that "scientists do make mistakes," and that for that reason he made no comment when he noticed in 1985 that the same graph had appeared in Dr. Rosen's articles of 1980 and 1984.

Chesapeake Bay scientists have proposed a string of permanent oyster sanctuaries on large reefs as part of a multimillion-dollar plan to revive the bay's oyster stock, which has been devastated in recent years by disease and overfishing.The reefs would cover 10 percent of the bay's traditional oyster-bar acreage in parts of the bay that historically yielded large harvests of oysters. Reefs would be set aside nearby for commercial harvesting under the plan, approved by scientists from Maryland, Virginia and North Carolina.

WASHINGTON -- A gene responsible for the most common type of cancer in humans has been found, two international teams of scientists reported yesterday.When the gene is damaged by ultraviolet radiation from the sun, it can produce skin tumors, known as basal cell carcinomas, that afflict about 750,000 people in the United States each year.Pale-skinned, middle-aged and older persons of Northern European ancestry are the most susceptible to these relatively harmless growths. If caught in time, they are easily removed with minor surgery or radiation.

Scientists studying 60 years in the life of a California tidal zone report today that populations of sea creatures, including snails, crabs, starfish and anemone, are migrating northward in reaction to rising ocean temperatures.While the shifts may have been helped along by a number of factors, including the so-called El Nino effect, the population changes may provide intriguing new evidence of the impact of global warming."The fact that creatures who prefer warmer water are now thriving in a place where they were once relatively rare came as a big surprise to us," said Charles Baxter, one of two scientists at the Monterey Bay Aquarium Research Institute in central California who headed the research project.

The inability to identify 10 everyday smells - from smoke to soap - can be used to predict Alzheimer's disease, scientists have discovered. The smell test was as effective at diagnosis as a memory test and better than a brain scan. "It's easy to do," said Dr. D.P. Devanand, a professor of clinical psychiatry and neurology at Columbia Presbyterian Medical Center. His findings were presented this week at the American College of Neuropharmacology meeting in Puerto Rico. While scientists have known for more than a decade that the brain's smell center is hard-hit in Alzheimer's, using smell tests to diagnose the disease has never caught on. Devanand has been testing the predictive value of a 40-item smell test developed by Richard Doty of the University of Pennsylvania.

New chemical tests devised in Canada are allowing scientists for the first time to identify the kinds of animals that were killed by Indians in Maryland many centuries ago.Tests on 10 ancient arrowheads recovered last month at an archaeological dig near Laurel -- the site of a 1,000- to 5,000-year-old Indian camp -- have revealed the presence of blood from rabbit, turkey and several other species, said R. Christopher Goodwin, a Frederick archaeologist.Such...