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Biomedical subjects

J F Dickson

Publications and source records attributed to J F Dickson.

16 recordsLinked to original sources
PubMed1990

The relationship of oral contraceptive use to rheumatoid arthritis.

Current use of oral contraceptives among 71 women aged 17 to 45 diagnosed for the first time as having definite or probable rheumatoid arthritis at Group Health Cooperative of Puget Sound was compared with oral contraceptive use among matched controls. Twenty-three percent of cases and 13% of controls were current users of oral contraceptives at the index date (relative risk estimate = 2.0, 95% CI = 0.97-4.21). We conclude that current oral contraceptive use was not protective against the development of rheumatoid arthritis in this population.

Adolescent↗
PubMed1985

A followup study of ibuprofen users.

We followed up 13,230 members of the Group Health Cooperative of Puget Sound under the age of 65 years who were presumed to have taken ibuprofen as out patients. All hospitalizations that occurred within 3 months after a prescription for ibuprofen was filled were reviewed. We found no instances of serious uncommon illness which could be attributed to this drug with any reasonable degree of certainty. In particular, there were no cases of acute liver or kidney disease noted within 3 months of exposure to ibuprofen.

Adult↗
PubMed1968

Some effects of discriminative training with equated frequency of reinforcement.

Pigeons were exposed to a multiple schedule which provided equally frequent reinforcement in the presence of two stimuli but which produced markedly different rates of key-pecking. Generalization gradients were displaced away from the stimulus associated with the lower rate of key-pecking. Another group of pigeons had similar training, except that a low rate of key-pecking was established in a stimulus with a much higher frequency of food reinforcement. In this case, the generalization gradients were not affected by the training on the schedule producing a low response rate.

Animals↗
PubMed1966

Some effects on generalization gradients of tandem schedules.

The relationship between training conditions and stimulus generalization gradients was examined using tandem schedules of reinforcement. Schedules were selected so that frequency of reinforcement and rate of responding were varied somewhat independently of each other. A peak-shift in the generalization gradient was obtained when extinction had been associated with one of the stimuli. No comparable peak shift was obtained when there were equal response rates in the training stimuli even with dissimilar frequencies of reinforcement. The data imply that response rates at the end of training, rather than reinforcement frequency per se, determine the characteristics of the generalization gradient.

Animals↗