In no case has a persistent agent been identified.

It is a requirement when people have been contaminated with persistent agents.

Defense against persistent agents requires shielding for extended periods of time.

Chemical decontamination is also a requirement if operations are to be continued after an attack by a persistent agent.

A special form of persistent agents are thickened agents.

These persistent agents need not be breathed.

And it is a persistent agent.

Deployment of persistent agents is intended to constrain enemy operations by denying access to contaminated areas.

"These persistent agents can remain toxic for weeks," Dr. Tucker said, "so that could have a significant effect."

By contrast, persistent agents tend to remain in the environment for as long as several weeks, complicating decontamination.

Mustard gas was also a persistent agent, which could linger for up to several days at a site, an additional demoralising factor for their opponents.

Section A-3 (Detection of Persistent Agents)

Chronic compression of the nerve root by a persistent agent such as disc, bone (osteophyte) or scarring can also permanently damage the nerve root.

White areas within dark-colored gall xylem of some samples were free of most of these abnormalities, suggesting that a persistent agent is required for continuing tumor growth.

There were still a few small debts, persistent agents, forlorn hopes, who pestered Rab, who - on wise advice, another cheat - would only pay the house insurance.

All of the V-agents are persistent agents, meaning that these agents do not degrade or wash away easily and can therefore remain on clothes and other surfaces for long periods.

To give a letter of introduction for the same reason that one sometimes buys goods of a persistent agent--to get rid of him--is a very poor way out of the difficulty.

"Because they are non persistent agents, they dissipate very quickly," said Hamish de Bretton-Gordon, a former head of Britain's military counter-nuclear, biological and chemical warfare force and now a private contractor.

For decontaminating equipment and buildings exposed to persistent agents, such as blister agents, VX or other agents made persistent by mixing with a thickener, special equipment and materials might be needed.

Frank (Leonardo DiCaprio) soon catches the eye of the FBI, and the new cheque fraud department of the FBI, who assign the very persistent agent, Carl Hannratty (Tom Hanks).

Biodegradation of persistent agents such as GD (the expected Soviet agent of choice; for an analysis of Soviet literature on this topic, see Appendix C of Annex 2) will be slowed by generally mild temperatures and weather-reduced sunlight photochemical action.