Letters.

Take my dog, please

As a trainer of tracking dogs, I was interested in your article about attempts to duplicate electronically the scenting ability of dogs ("Eau, brother!" SN: 2/19/00, p. 125). Even if these expensive, high-tech artificial dog noses are successful, however, they are not likely to be of much benefit to the "62 countries worldwide" strewn with "more than 100 million land mines." Wouldn't it make more sense to show people in these countries how to train their own low-tech dogs to find mines?

Some dogs, of course, would die in the line of duty, but on balance, dogs in which training time has been invested might be treated as valuable resources, which is better than dogs are treated in many of these countries.

Craig F. Bohren Oak Hall, Penn.

Explosive detectors that use an electronic nose need not be expensive or difficult to use. John Sikes, assistant product manager for Nomadics, says the devices should cost less than $5,000 and look like (and be used like) a regular metal detector. However, training a sniffer-dog-handler team takes about 17 weeks and $25,000, according to David Kontny, manager of the Federal Aviation Administration's Canine and Explosives Branch.

--S. Perkins

News flash

It comes as no surprise to me that the findings of the study in "Good readers may get perceptual lift" (SN: 3/18/00, p. 180) may have implications for teaching kids to read better. Historic perspective suggests that rapidly presented acoustic and visual stimuli can benefit reading instruction, as Tallal asserts. We knew this process as "flash cards" when I was in school.

Michele Hand Missoula, Mont.

The article reports a lower ability to read among 10-year-olds with less ability to detect low-frequency sound. Audiologists say that chronic ear infections in infants can cause loss of low-frequency response. That makes me wonder if the lower reading ability reported is due to loss of the low-frequency response or if it is due to less sound stimulation when young.

The other finding in the article is that visual acuity correlates with increased ability to spell. I wonder if the same correlation would hold for speakers of more phonetically spelled languages like Spanish or Japanese, or for reading and writing Chinese, which is completely nonphonetic.

Ivan Mann Hoover, Ala.

Mark of a promising technology

It occurs to me that the techniques described in "Molecules leave their mark" (SN: 3/18/00, p. 186) could have a wide variety of applications outside the biological sciences. For example, imprinted high-temperature ceramic materials could be used as less-expensive catalysts in automobiles and factory emission--controls systems. And filters made from such materials might be used to greatly reduce the quantity of pollutants released into waterways as wastewater from chemical-refinement processes or even to extract useful byproducts from these waste materials. Indeed, the possibilities of this new technology seem limitless.

Michael Bell Elizabeth, N.J.