Developmental criteria

Evaluation, characterization, and testing of a particular analytical method is necessary to ensure the intended use of the method is met. In general, this process requires the determination of intra-and interlaboratory studies for precision and bias, method detection limits, matrix effects, interferences, limits of reliable measurements and ruggedness of the method. Before the EPA commits time and resources for an in-depth evaluation study, the developer must meet certain developmental criteria or justify why they were not met. The developer must also clearly define all necessary reagents as well as the underlying basis of the immunoassay. 

The fundamentals of testing for reproductive and teratogenic effects of chemical agents were described by Dr. R. Tyl. She laid emphasis on teratogenic phenomena in man, one-fifth of which were attributable to germinal mutations. Developmental criteria and landmarks in rodents were tabulated to illustrate the important applications of such data in safety testing. 

Extensive reviews of active instability suppression techniques are found in McManus et al. [18] and Candel [19]. Also, Zinn and Neumeier [20] provide an overview of research and developmental needs for practical applications. Most of the previous studies have used actuators impractical in liquid-fueled systems, such as loudspeakers that impose acoustic perturbations on gaseous flow. The major emphasis in the present study was to establish active instability suppression using liquid-fuel injection. According to Rayleigh s criterion [21, 22], combustion-acoustics interaction can be used to damp the undesirable oscillations provided that pressure fluctuations p and heat release fluctuations q satisfy the proper phase relation such that... 

Changes in transcription at various developmental stages provide one criterion for identifying genes that play a critical role in cell regulation and differentiation. A more important... 

Level 3 assessments also require detailed measures of child function in major developmental areas. In addition, if more than one recommended instrument is available for a given function, then a second recommended instrument that assesses either converging or complementary functions should be used on each assessment occasion. Assessment on at least two separate occasions is required within the first year. Level 3 assessments are required when the criteria for level 2 assessments are met and/or the following additional criterion occurs ... 

The temporality criterion among the Hill causality proofs can be readily answered in the affirmative. For example, one aspect of temporality that was once of concern was the potential existence of reverse causality, i.e., is elevated blood lead concurrent with a developmental neurotoxic endpoint because the neurotoxic impairment enhances lead exposure rather than the reverse The outcomes of multiple prospective epidemiological studies of lead neurotoxicity in children effectively ruled out the likelihood of reverse causality. 

Strain difference in radiosensitivity has been studied extensively in the silkworm, and seven representative strains, sensitive, intermediate, and resistant, have been established.These were first extracted from the worldwide collection of silkworm strains maintained at the National Seri-cultural Experiment Station, Tokyo, using embryonic killing as a criterion. The difference in mutation response between the most and the least sensitive strains is about 7- to 9-fold when spermatogonia are irradiated. However, it becomes smaller with the progress of the developmental stage of those germ cells, namely, 2- to 4-fold in spermatids and almost unity when mature sperm were irradiated (for details, see Tazima ). 

To elucidate the mechanism(s) underlying the discordance, Murakami and Tazima compared the metabolic activation potentialities of these two insects using the mutagenicity to Salmonella as a criterion. In this experiment, microsome fractions of the silkworm were prepared from the whole-body homogenates of silkworms at various developmental stages. The technique was almost the same as that reported by Ames et except that no enzymatic... 

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