Ascaris lumbricoides suum: thermal death time of unembryonated eggs.
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Animals↗
Biomedical subjects
F D McClure
Publications and source records attributed to F D McClure.
Performance of disturbed hyperactive and nonhyperactive children on an objective measure of hyperactivity.
Twenty hyperactive emotionally disturbed children (6-11 years) and a matched sample of nonhyperactive emotionally disturbed children were selected from the population of a therapeutic day treatment facility on the basis of teacher ratings. They were administered the Matching Familiar Figures Test-20 and were rated on several scales of impulsivity and/or hyperactivity. Each subject was required to perform on the Delay Task of the Gordon Diagnostic System, which required them to inhibit behavioral responding on a temporally based schedule (DRL-6) in order to win points. Children classified as hyperactive, whether by one or more criteria, were relatively unable to refrain from emitting a high number of nonreinforced responses. Moreover, these performance differences persisted regardless of age or IQ and were stable over the 8 minutes required to complete the test.
Affective Symptoms↗
Recovery of eggs of two parasitic nematodes, Ascaris sp. and Trichuris sp.: Interlaboratory study.
An interlaboratory study was conducted to determine the effectiveness of the Nacconol ether centrifugation method for recovering parasitic nematode eggs from 3 contaminated products: a crop (cabbage), a sludge fertilizer (Milorganite), and a sewage effluent (Minneapolis). Six replicate samples for each of the 3 products were seeded with eggs at 3 different levels: 200 Ascaris suis and 8 Trichuris muris; 15 A.suis and 15 T.muris; 8 A.suis and 180 T.muris. Recovery was low for all samples except sewage effluent, in which recoveries greater than 100% in 2 samples resulted from the misidentification of arthropod eggs as Ascaris sp. The average mean percent recovery for the other samples was 22.53. Repeatability for replicate samples and reproducibility of results by individual laboratories were poor, and the method is not recommended for quantitative estimates of nematode egg contamination of foods and food-contact materials. However, the Nacconol ether centrifugation method can be used as an all-or-none test. (Only 13% of 1146 counts were falsely negative.) Of 69 samples, only 4 were falsely negative for A.suis eggs and only 1 was falsely negative for T.muris eggs in counts of 6 replicates.
Animals↗
Usefulness of the stomacher in a microbiological regulatory laboratory.
The relative efficiency of the Waring blender, the Stomacher 400, and the Stomacher 3500 for preparing food samples for microbiological analysis was studied. Comparative aerobic plate count (APC) values were determined on 671 samples, representing 30 categories of foods. Of the 26 categories of nonfatty foods, the blender gave significantly higher geometric mean APC values than those given by the Stomacher 400 and the Stomacher 3500 in 65 and 69 percent of the categories, respectively. In a comparison of the two Stomacher models, the Stomacher 400 gave significantly higher geometric mean APC values than these given by the Stomacher 3500 in 73 percent of the food categories. Addition of Tween 80 to four categories of fatty foods at concentrations of 0.5, 1.0, and 2.0 percent did not raise the APC values given by either model of stomacher to the levels given by the Waring blender. Overall, the efficiency of both models of Stomacher, relative to the blender and to each other, was specific and depended upon the particular food being analyzed.
Bacteria↗
Enumeration of coliforms and Salmonella in food prepared by blending and stomaching.
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Bacteriological Techniques↗
Design and analysis of qualitative collaborative studies: minimum collaborative program.
Collaborative studies involving qualitative data are usually conducted under design constraints to fulfill the requirements for quantitative studies. The data from these qualitative studies are often analyzed in a manner that ignores the fact that collaborative studies involve matching (i.e., each laboratory analyzes a portion of each test sample). This report presents some design considerations and analysis procedures for qualitative collaborative studies that take into account that the design involves matching. Suggestions are offered as to the number of laboratories and test samples to use in the minimum collaborative program, and analysis procedures for outier screening are detailed. Method performance is assessed through such indicators as sensitivity, specificity, false positive, and false negative rates. Methods for estimating the error of the performance indicator rates are explained, and procedures are given for estimating false positive and false negative rates for lot defect rates that may occur in practice.
Chemistry Techniques, Analytical↗
Statistical sampling approaches.
This article describes basic sampling principles and the application of statistical sampling techniques to specific problems encountered in the Food and Drug Administration (FDA). Concepts are emphasized, and theory is minimized. The basic principles of sampling from a normal and binomial population, including confidence interval calculation and sample size determination, are briefly reviewed. Stratified, random, systematic, and judgment sampling are explained. Operating characteristic curves for attribute (and perhaps variable) sampling for acceptance of lots are derived and applied to specific FDA problems. The advantages and disadvantages of single and multiple sampling plans and plans which address multiple classes of criteria such as major and minor defects are discussed. Sampling schedules such as MIL-STD-105D and Canada's Government Specifications Board CGSB-105-GP-1 are reviewed to familiarize readers with the principles involved in these plans and to give them an idea of how they could be applied to FDA problems.
Chemistry Techniques, Analytical↗