Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by …

Manual/guide providing information/instructions about revisions to the standards and guidelines for school library programs, including the six major components of school library programs, strategies for librarians, output measures, and outcome-based evaluations.

The final report of the evaluation of the Compressed Air Challenge (CAC) Training Program. The training program is designed to provide plant personnel and compressed air system vendors with knowledge and tools required to effect improvements to the energy efficiency and overall performance of plant compressed air systems. As of May 2001, 3,029 individuals had attended the CAC Fundamentals of Compressed Air Training Systems and 925 individuals had attended ''Advanced Management of Compressed Air Systems''. These individuals represented 1,400-1,500 separate business establishments. The evaluation is based on three main research tasks: analysis of the CAC registration database, interviews with 100 end-user personnel who attended the CAC training, and interviews with 100 compressed air system vendors and consulting engineers who attended the training sessions.

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.