Developments to Watch
Rewinding the Biological Clock
The fountain of youth burbles away in egg cells, according to researchers at Advanced Cell Technologies, a biotech company in Worcester, Mass. In the Apr. 28 issue of Science, they report that cells from six cow clones show no signs of the premature aging that has affected other clones such as the sheep Dolly. In fact, their studies suggest the cloning process actually made old cells young again. "We've rewound the biological clock," says Michael D. West, ACT's chief executive officer.
The ACT scientists utilized a different method to create their clones than was used to make Dolly. They harvested DNA from skin cells at the end of their life spans and transferred it to egg cells stripped of genetic material. After the cloning process, the cells appeared to be reborn. Instead of being less than four cell divisions away from death, like the original skin cells, they survived for 90 cell divisions.
West and his colleagues aren't sure how cloning sends cells into a time warp. Nor do they know whether this process will extend the lives of animals that develop from such cells. But the results should quell rising skepticism about cloned cells' utility. West believes that someday the technique could generate a bountiful supply of healthy tissue, which could replace diseased cells in people with Parkinson's, Alzheimer's, and heart disease.
Other specialists who are familiar with the research agree. Says Leonard Hayflick, a professor at the University of California at San Francisco and an expert in aging research: "The study represents a milestone in our efforts to understand how longevity is determined."By Ellen LickingReturn to top
Biological Hot Spots Threatened by Human Activity
Halting the loss of earth's biodiversity is one of the greatest environmental challenges of our time. Of the many factors that contribute to this loss, human activity is particularly threatening.
Now, for the first time, scientists at Population Action International have quantified the human population dynamics in three tropical forest areas and 25 other biodiversity "hot spots"--Sri Lanka, the Philippines, and the Caribbean, among others--that harbor a myriad of unique plants and animals. The researchers estimate that in 1995, more than 1.1 billion people, or nearly 20% of the world's population, were living in such hot spots. Population growth in these regions was also substantially higher than the average for all regions. Such growth increases risks to precarious habitats.
To quantify changes in population, Richard P. Cincotta and his colleagues used geographic information systems (GIS), in which population, land area, and biodiversity are represented by pixels that correspond to numerical data. When Cincotta's team overlaid a digital map of the biodiversity hot spots with a second map that charted population, they found that some of the regions with the fastest growth were also some of the planet's most treasured habitats. The results were published in the Apr. 27 issue of Nature.By Ellen LickingReturn to top
A Sucker for a Pretty Pool
Summer nights, and the living is easy--that is,if you have somebody--or some thing--to clean the pool for you. Zodiac Pool Care Inc. of Fort Lauderdale is selling a $600 automatic pool cleaner called Mars that boasts a number of advantages over existing pool robots. Because it is spherical, Mars can navigate a pool of any shape--even a square one--scaling walls and stairs without getting hung up on tricky corners. Zodiac claims that it takes this vacuum less than three hours to clean a typical 15 by 30 foot pool.
Developed by Zodiac's own engineers and designers, Mars looks like the head of R2D2 in Star Wars. It works by creating a flow of water to propel itself across the pool floor. Water enters the appliance through a pair of jets, creating the suction needed to vacuum up fine sand, acorns, oak leaves, and other debris. With one-third fewer parts than other pool cleaners, Mars is also practically maintenance-free, according to Zodiac.By Ellen LickingReturn to top