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Biomedical subjects

J Tapp

Publications and source records attributed to J Tapp.

6 recordsLinked to original sources
PubMed2001

Sequential analysis of the effects of naltrexone on the environmental mediation of self-injurious behavior.

Accumulated evidence shows that biology and the environment can mediate self-injurious behavior (SIB) in persons with mental retardation. Whether pharmacological treatment alters the environmental mediation of self-injury is unclear. Opioid antagonist effects on sequential dependencies for self-injury were studied in the context of experimental single-subject double-blind placebo-controlled designs. Direct observational data were collected for 4 adult subjects in real time on daily rate of SIB and staff interactions. Clinically significant reductions (i.e., > or = 33%) in SIB rate were observed for 3 of the 4 subjects. For all subjects, the magnitude of the sequential dependency between staff behavior and self-injury was significantly greater during treatment with naltrexone than during treatment with a placebo. Results are discussed in relation to behavioral mechanisms of action regulating medication effects for self-injury.

Adult↗
PubMed2001

Comparing sequential associations within a single dyad.

We present a new application of sampled permutation testing to examine whether two sequential associations are different within a single dyad (e.g., a teacher and a student). A Monte Carlo simulation with the same (i.e., 100 vs. 100) or a different (100 vs. 400) number of event pairs was used to simulate designs that use time-based (typically producing equal-length comparisons) and event-based (typically producing different-length comparisons) data, respectively. For these pairs of simulated data streams, we compared the Type I error rates and the kappa for agreement on significance decisions, using the sampled permutation tests and the more traditional asymptotic log linear analysis. The results provide the first evidence relevant to evaluating the accuracy of log linear analysis and sampled permutation testing for the purpose of comparing sequential associations within a single dyad.

Behavioral Sciences↗
PubMed1998

Aquatic toxicity testing of sparingly soluble, volatile, and unstable substances and interpretation and use of data. Task Force of the European Centre for Ecotoxicology and Toxicology of Chemicals.

Aquatic toxicity tests were originally designed for individual compounds that are soluble and stable in water. For sparingly soluble substances that are not toxic at the solubility limit, the issue is whether tests should be performed with insoluble test substance present. Based on a literature evaluation of the physiology of uptake, it was concluded that only the dissolved fraction is available for uptake and that the insoluble test substance may introduce artifacts that aggravate data interpretation. Therefore, toxicity tests should be conducted only up to the solubility limit. Testing of volatile, unstable, or adsorptive substances is complicated by the ability to keep exposure concentrations relatively constant. For these, appropriate test protocols including adequate design of the dosing systems must be employed. For test medium preparation, physical methods and, where necessary, use of low concentrations of certain solvents are recommended to support handling and speed of dissolution. However, recommendation is made against the use of dispersants. Water-accommodated fractions are recommended as one approach for dosing multicomponent substances. Interpretation of observed effects depends on appropriate test medium preparation, correct measurement and expression of exposure levels, and differentiation of true toxicity from indirect physical effects of the substance, or the toxicity of impurities.

Adsorption↗
PubMed1979

A structured experiential curriculum in community medicine.

In order to provide experimental training in community medicine, a structured curriculum has been developed. Specific methodological skills in community medicine are identified and nine content areas are presented in seminar form during the three-year training program. Each resident is expected to participate in a community health care project and demonstrate one or more of the methodological skills identified. The experiences of two residents are reported. One involved a community health needs assessment and one, the development of a mechanism to ensure continuing consumer/provider communication.

Community Medicine↗