Morphine dependence in rats assessed in a shock discrimination task.

The effects of chronic morphine sulfate (5 mg/kg/day for 14 days) on shock discrimination performance of rats was assessed in Experiment 1. Significant tolerance developed to the disruptive effects of morphine on performance. A significant increase in discrimination performance was found 48 h after the last injection in tests conducted without the injection environment cues present. Ten days after the chronic drug regimen, tests conducted 30 min after exposure to the injection-environment cues revealed no differences between animals previously administered morphine and control animals administered saline. In Experiment II, shock discrimination performance was assessed in a separate group of rats after exposure to a single injection of morphine sulfate (30 mg/kg), which eliminated associative processes, e.g., Pavlovian or instrumental conditioning, as factors in the subsequent behavioral tests for hyperalgesia. Significant changes in discrimination performance (primarily enhanced percent correct to the high shock stimulus) indicative of increased pain sensitivity were obtained in tests conducted 1, 2, and 3, but not 9 days after the injection. These experiments indicate that increased pain sensitivity, as opposed to hyperresponsivity operationally measured in traditional analgesia tests (e.g., hot plate, jump-flinch, and tail flick), is a component of morphine withdrawal of a nonassociative origin.

Love, self-esteem, and multiple sclerosis.

Multiple sclerosis (MS) is a progressive chronic disease which generally appears in early adulthood. The debilitating symptoms of MS can have adverse effects on the sufferer's self-esteem, a vital coping resource for sufferers of chronic diseases. This study explores the effects of positive affect and social isolation--conceived broadly together as love--on self-esteem. We found that love was the most powerful predictor of self-esteem, followed by attitude stage, number of years since diagnosis, social class, and physical restriction.

The changing environment of a desert boomtown.

World population growth has prompted the exploration and habitation of geographical regions previously considered undesirable or unsuitable for human comfort. The impact of humans and their civilization on desert regions, where water and vegetation are scarce, is not well understood. The high plains desert of the southwestern United States is the fastest growing region of the nation. Historically, the desert atmosphere was distinguished by extraordinary visibility and negligible particle and chemical pollution. Unfortunately, visitors and residents of the region have perceived a decline in the air quality during a 15-20-year period which corresponds to a rapid influx of population and the development of isolated urban areas. This study attempts to assess the relative impacts of demography, meteorology and air chemistry on the air quality of a rapidly growing, small city located in the Mohave Valley on the Nevada/Arizona border. Statistically significant trends were identified in the local meteorology and air quality over a 10-year period. Temperature and relative humidity values were observed to increase at the urban site. Increases were also noted in the concentrations of total suspended particulates (TSP) and the oxides of nitrogen. Observations at the urban site were compared with similar measurements at nearby non-urban sites and with the results of studies at two larger cities in the desert southwest, Phoenix and Tucson, AZ. Conclusions based on the combined analyses indicate that the desert environment has been strongly influenced in the immediate urban area and that the changes are due primarily to demographic influences. Changes in urban air quality observed in the Mohave Valley were more pronounced and were apparent over a shorter period of time than air quality changes observed elsewhere in the southwest.

JSD and the design of user interface software.

Systems analysis and design methods (SADMs), such as Jackson system development (JSD), have been proposed as a means of improving software quality. This is contrasted with the role of improving software usability proposed for human factors (HF). The paper argues the need for an explicit user interface specification stage in system development to ensure the usability of proposed systems. It is suggested that JSD supplemented by the specialist knowledge of HF can support such a specification stage. For HF and JSD to be successfully integrated, contributions from both need to be appropriately timed and structured. A model of the system development process that incorporates HF contributions is proposed. A means by which the HF contributions, in the form of a user interface specification, can be integrated with the JSD specification is developed and illustrated through examples.

Group exposure for agoraphobics: a replication study.

A replication study was conducted of the treatment of agoraphobics by exposure in cohesive groups, as described by Hand, Lamantagne and Marks (1974). The continuing improvement during follow-up, with consequent large overall improvement, reported in the original study was not replicated. However, the present study confirmed the usefulness of this procedure as a highly cost-efficient treatment. The assumed equivalence of the Gelder and Marks (1966) phobic rating scale and its modification by Watson and Marks (1971) was examined. Large discrepancies between the scales were obtained for initial assessments and change scores. It is suggested that there is a need for workers in this field to agree on methods of measurement.