Developments to Watch
A SWEETER LIFE FOR CROPS IN SALTY SOIL
FARMERS HAVE MADE STEADY GAINS AGAINST PESTS AND DISEASES in recent years. But salty soil has proven a tougher enemy. Every year, California alone loses some $500 million in stunted crops and fields that must be abandoned because of excess salt. Now, molecular biologist Julian Schroeder of the University of California at San Diego says he has identified a gene, called HKT1, that regulates salt uptake in wheat. By manipulating the gene, scientists may be able to create salt-resistant crops.
HKT1 codes for a protein on the surface of roots that acts as a molecular highway. It lets in sodium, a key component of salt, as well as potassium, a vital nutrient. Schroeder transplanted HKT1 into yeast cells, exposed them to salt, and deftly culled resistant mutations. The mutant genes make proteins that let less sodium into the root than natural proteins do without blocking potassium. Before tackling wheat, Schroeder will work with mustard plants, which are easier to genetically engineer.EDITED BY NEIL GROSSReturn to top
CYBERSCRIP: WHEN A PENNY IS TOO MUCH TO PAY
AS THE INTERNET GOES COMmercial, cybercapitalists are wondering how much people would be willing to ante up to visit a given site on the World Wide Web. Concluding that, in many cases, even 1 cents might be excessive, Web mavens at Digital Equipment Corp. have devised a way to mint "microcash," which would let customers pay for their Web explorations in fractions of pennies.
No money has changed hands yet. But in August, DEC filed a patent on a payment system called Millicent. Like some other digital-cash schemes, it relies on middlemen--credit-card companies or digital banks--to issue scrips worth as little as a tenth of a penny to Web-site operators each time a customer "hits" their sites.
Unlike other digital-cash ideas, however, Millicent is cost-effective at tiny increments. To keep disk storage and computational overhead to a minimum, its designers stripped away certain types of guarantees, such as privacy, or a trail of signed receipts on each purchase. But that shouldn't deter customers who simply want to click from one home page to another. Proponents point out that would-be digital thieves would need to crack the security on 10,000 or more transactions worth 0.1 cents each in order to make off with just $10. Says Mark Manasse, the inventor of Millicent: "There are easier ways to make 10 bucks."EDITED BY NEIL GROSSReturn to top
ARE BACTERIA BEHIND BLOCKED ARTERIES?
DOCTORS KNOW A LOT ABOUT risk factors for atherosclerosis--the buildup of plaques in artery walls that can block blood vessels and lead to heart attacks. Cigarette smoking, obesity, and high cholesterol levels are some major ones. But what causes plaques to accumulate in the first place? Researchers at the University of Washington say the culprit could be a common bacteria strain that most people are exposed to in childhood.
Dr. J. Thomas Grayston, a professor of epidemiology, speculates that the bacteria--Chlamydia pneumoniae--may either directly trigger the buildup of plaques or encourage their growth once the process starts.
In a study published in the December issue of Circulation, Grayston found that almost 60% of tissue samples taken from blocked carotid arteries harbored the bacteria. That doesn't prove chlamydia is responsible. But ongoing tests on mice may provide the missing evidence. If so, since chlamydia is killed by antibiotics, Grayston will propose human trials to see if such drugs can help patients with the telltale plaques.EDITED BY NEIL GROSSReturn to top