To the Editor: Until we know whether spam is generally profitable or the product of virtual vandals, more sophisticated filters or taxes or other proposals to halt this disease are doomed to failure.

Detectors the size and weight of battleships are installed at points around the ring where protons collide, and sophisticated filters and sensors in the detectors gather up the particle debris and analyze it.

Moreover, most major e-mail providers have built sophisticated filters that divert much of the spam.

It has also developed a sophisticated ceramic filter for milk, derived from one for nuclear coolant.

Workers were cleaning a blockage in one of the eight condensate polishers (sophisticated filters cleaning the secondary loop water), when, for reasons still unknown, the pumps feeding the polishers stopped.

In more sophisticated filters, the coefficients normally have non-integer values to "tune" the output of the filter to pass different frequencies.

Chickens are a lot more stupid than humans, and don't have the sophisticated mental filters that prevent them seeing what is truly there.

CYBERsitter, which touts its sophisticated content-based filters, blocks all sites with the word "anarchy."

Even with sophisticated anti-aliasing filters used in the recorder, it is still demanding for the player not to introduce more distortion.

This means that the city's plans to eliminate barnyard runoff and add sophisticated filters to sewage plants may be misdirected.