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Biomedical subjects

R O Nelson

Publications and source records attributed to R O Nelson.

At least 19 recordsLinked to original sources
PubMed2005

Neutron multiplicity in the fission of 238U and 235U with neutrons up to 200 MeV.

Prompt-fission-neutron multiplicities were measured for 238U(n,f) and 235U(n,f) from 0.4 to 200 MeV. The data are of great importance in connection with accelerator-coupled nuclear reactor systems incinerating actinides. We report that fission induced by 200 MeV neutrons produces approximately 10 more prompt neutrons than fission induced by reactor neutrons. Most neutrons are evaporated from the fission fragments and the prefission compound nucleus, as the preequilibrium emission of energetic neutrons accounts for a maximum of 15% of the prompt neutrons at 200 MeV.

Journal Article↗
PubMed1988

The effectiveness of activity scheduling and relaxation training in the treatment of spasmodic dysmenorrhea.

The first purpose of this study was to examine the effectiveness of activity scheduling as a treatment for spasmodic dysmenorrhea, compared to relaxation training (a treatment of demonstrated effectiveness) and to a waiting-list control condition. The second purpose was to examine the differential effectiveness of these treatments on different measures. Forty women suffering from spasmodic dysmenorrhea completed six individualized treatment sessions or remained on the waiting list. Results showed that both activity scheduling and relaxation training were effective treatments for spasmodic dysmenorrhea, with both treatments producing improvements on general measures of dysmenorrhea, a symptom severity measure, and an activity measure.

Adolescent↗
PubMed1987

Behavioral measures of multiple personality: the case of Margaret.

This report concerns the systematic study of a 28-year-old subject diagnosed as multiple personality. The purpose of this study was to examine similarities and differences in three of her distinct personalities, utilizing behavioral measures. Three tasks were presented to the personalities: a memory task; a perceptual-motor task; and an attention task utilizing event-related potentials. The memory task and perceptual-motor task indicated that the three personalities shared information and that learning extended from one personality to the next. The attention task indicated that the three personalities were differentially processing the stimuli that were presented to them, as measured by the ERPs. The results are discussed in the context of the individual case and of the phenomena of multiple personality.

Adult↗
PubMed1987

Psychological treatments of dysmenorrhea: differential effectiveness for spasmodics and congestives.

Two studies are reported, examining the effectiveness of psychological treatments for dysmenorrhea. In Experiment 1, 33 women with spasmodic dysmenorrhea were treated with relaxation alone, or relaxation plus imagery, or assigned to a waiting-list control condition; and 29 women with congestive dysmenorrhea were treated with relaxation alone, or assigned to a waiting-list control condition. In Experiment 2, 18 additional congestives were treated with a coping skills package, or this package plus relaxation; these two groups were compared with the two congestive groups from Experiment 1. The dependent measures were reports of symptom severity, general discomfort, resting time, and medication use. Consistent with the literature, the main findings of the present studies are: (a) relaxation training (alone or with imagery) effectively reduces resting time for spasmodics; and (b) none of the treatments was shown to be effective for congestive sufferers.

Adaptation, Psychological↗
PubMed1987

Self-instruction: An analysis of the differential effects of instruction and reinforcement.

This study investigated the impact of training 9 first- and second-grade children to use a full self-instructional regimen, and then differentially reinforced the use of self-instruction only, accuracy only, or both self-instruction and accuracy. Three comparison children received no training in self-instruction and were reinforced for accuracy only. Children improved dramatically in academic accuracy subsequent to self-instructional training, independent of the use of self-instruction and of the specific behavior consequated. Children who were reinforced for using self-instruction did use self-instruction, and those who were not, did not. Comparison group children showed little improvement until training in problem-solving strategies was given after 9 days of reinforcement for accuracy. Self-instructional training is discussed as one type of event that increases the likelihood of accurate performance. Its effectiveness may be explained in terms of a teaching strategy rather than in terms of modifying cognitive processes.

Journal Article↗
PubMed1986

Equivalence class formation in language-able and language-disabled children.

Stimulus equivalence seems to have relevance to the study of semantics and of language more generally. If so, there may be a relation between language use and the demonstration of stimulus equivalence. This was examined in three groups of children ranging in chronological age and matched on a conventional measure of mental age: normally developing preschoolers, retarded children who used speech or signs spontaneously and appropriately, and retarded children who did not. All children were taught a series of four related discriminations and were then tested to determine if classes of equivalent stimuli had formed. All of the language-able children (retarded and normal) formed equivalence classes, whereas none of the language-disabled children did so. Although the exact nature of the relation between stimulus equivalence and language remains to be clarified, these results support the view that stimulus equivalence is a phenomenon with relevance to language.

Child, Preschool↗
PubMed1981

The effects of instructions and calculation procedures on observers' accuracy, agreement, and calculation correctness.

Although the quality of observational data is generally evaluated by observer agreement, measures of both observer agreement and accuracy were available in the present study. Videotapes with a criterion protocol were coded by 16 observers. All observers calculated agreement scores both on their own and their partner's data and on a contrived data set misrepresented as data collected by other observers. Compared with agreement scores calculated by the experimenter, observers erroneously inflated their own agreement scores and deflated the agreement scores on the contrived data. Half of the observers (n = 8) had been given instructions emphasizing the importance of accuracy during observation while the other half had been given instructions emphasizing interobserver agreement. Accuracy exceeded agreement for the former group, whereas agreement exceeded accuracy for the latter group. The implications are that agreement should be calculated by the experimenter and that the accuracy-agreement relationship can be altered by differential observer instructions.

Journal Article↗