A new paradigm in patient education: a four-part model using videotape production.

In this article, the effectiveness of an instructional videotape for newly admitted hospitalized psychiatric patients is discussed and evaluated. It is suggested that by using 'actors' with whom the patient is familiar (hospital staff), the educational and therapeutic benefit of the video is enhanced. This paper provides a method for pre-production planning of an effective videotape based on a four-part model. In this model, the educational subject matter is divided into four categories; facts, procedures, support, and mastery. An attempt is made to match various styles of presentation by each member of the treatment team to the nature of the part being presented. The short attention span common to newly admitted depressed patients, for example, is remedied by the use of concise messages delivered by each treatment team member. Although videotapes are not a substitute for one-to-one professional interaction, they can provide some basic understanding of the therapeutic environment and allay some of the fears that often plague the newly admitted patient. This paper also demonstrates how the use of videotaped instruction allows the treatment team to administer organized information using unlicensed personnel or the patient himself, thus conserving the professional staff's time.

Experimental factors that may affect toxicity of cadmium to freshwater organisms.

The effects of exposure duration, test organism, and test endpoint on the toxicity of cadmium to a variety of freshwater species were evaluated. Toxicity of cadmium was assessed by monitoring the survival and reproduction of Ceriodaphnia dubia Richard; the survival of Daphnia magna Straus; and the survival and growth of Hyalella azteca Saussure, Chironomus tentans Fabricius, and Pimephales promelas Rafinesque. Organisms were exposed in static systems for 48 h, 96 h, 7 d, 10 d, and 14 d to determine acute and chronic toxicity. Relative sensitivities of test organisms exposed to aqueous cadmium varied with test duration and test endpoint. In general, H. azteca was the most sensitive organism tested, followed in decreasing sensitivity by P. promelas, C. dubia, D. magna, and C. tentans. Mortality of C. dubia and D. magna was consistent up to 7 d, after which little additional mortality occurred. Effects of test duration on cadmium toxicity were most pronounced for H. azteca and C. tentans, with mortality and growth becoming increasingly sensitive with increasing test duration.

Partitioning and effects of silver in amended freshwater sediments.

Sediments that represented a wide range of characteristics were amended with silver compounds to observe partitioning and bioavailability. In laboratory studies, silver partitioning to particulates, sediment pore water, and overlying water was measured and bioavailability of silver was determined using Hyalella azteca in 10-day sediment toxicity tests. Three silver compounds were used as sources of silver for this study: silver nitrate, silver chloride, and silver thiosulfate complex. Sediment amendment procedures were adjusted as necessary depending on the characteristics of the individual compounds. Several sediment characteristics such as organic carbon, pH, redox, and acid volatile sulfides regulated silver partitioning and bioavailability. Bioavailability of silver was correlated with the overlying water concentration of silver. Ten-day LC50 values ranged from 1.62 to 379.7 mg Ag/kg for H. azteca exposed to sediments amended with AgNO3. In laboratory experiments, silver chloride and silver thiosulfate were orders of magnitude less toxic and bioavailable than silver nitrate, with 10-day LC50 values greater than the highest concentrations of AgCl and silver thiosulfate complex amended to sediments (2560 and 1125 mg Ag/kg, respectively.