IS THERE MORE TO COUNTING THAN WHAT MEETS THE EYE? COMMENT ON SNYDER AND RICE

Snhyder and Rice (1994) comment that Shortz, Worthington, McCullough, DeVries, and Morrow (1994) failed to use sophisticated methods in their identification of prolific authors, institutions, and journals within the field of mari-tal therapy. This article is a response to Snyder and rice. We argue that Snyder and Rice's suggested methods emphasize a different research question that ouroriginal question, We investigated productivity of authous and institutions, not im-pact of scholars on the fiels of marital therapy. furthermore, we demonstrate that the results obtained from Snyder and Rice's suggested methodologies are nor appreciably different from our original results.     

The U.S. EPA Geographic Information System for Mapping Environmental Releases of Toxic Chemical Release Inventory (TRI) Chemicals

This study characterizes the environmental releases of toxic chemicals of the Toxic Chemical Release Inventory (TRI) in the southeastern United States by using the U.S. Environmental Protection Agency (EPA) Geographic Information System (GIS) to map them. These maps show that the largest quantities of TRI releases in the Southeast are usually near densely populated areas. This GIS mapping approach takes the first steps in defining those areas in the region which may be potential exposure zones and which could be strategic targets for future risk screening efforts in this geographic area.     

Probabilistic Health Risk Assessment for Exposures to Estuary Sediments and Biota Contaminated with Polychlorinated Biphenyls, Polychlorinated Terphenyls and Other Toxic Substances

A Latin Hypercube probabilistic risk assessment methodology was employed in the assessment of health risks associated with exposures to contaminated sediment and biota in an estuary in the Tidewater region of Virginia. The primary contaminants were polychlorinated biphenyls (PCBs), polychlorinated terphenyls (PCTs), polynuclear aromatic hydrocarbons (PAHs), and metals released into the estuary from a storm sewer system. The exposure pathways associated with the highest contaminant intake and risks were dermal contact with contaminated sediment and ingestion of contaminated aquatic and terrestrial biota from the contaminated area. As expected, all of the output probability distributions of risk were highly skewed, and the ratios of the expected value (mean) to median risk estimates ranged from 1.4 to 14.8 for the various exposed populations. The 99th percentile risk estimates were as much as two orders of magnitude above the mean risk estimates. For the sediment exposure pathways, the stability of the median risk estimates was found to be much greater than the stability of the expected value risk estimates. The interrun variability in the median risk estimate was found to be +/-1.9% at 3000 iterations. The interrun stability of the mean risk estimates was found to be approximately equal to that of the 95th percentile estimates at any number of iterations. The variation in neither contaminant concentrations nor any other single input variable contributed disproportionately to the overall simulation variance. The inclusion or exclusion of spatial correlations among contaminant concentrations in the simulation model did not significantly effect either the magnitude or the variance of the simulation risk estimates for sediment exposures.     

Amicable divorce

Traditional marriage viewed divorce as a deviant phenomenon based on the commission of a fault by one partner against the other, leaving the aggrieved partner feeling resentful and the allegedly guilty party feeling guilty. Changing attitudes toward marriage now see divorce as an appropriate consequence of personal growth and change, no longer implying that one partner is at fault. No-fault divorce promotes amicable attitudes between the ex-partners. They may remain friends with one another and with their common old friends and separate new friends and partners. They typically remain coparents, sharing the decisionmaking authority and financial responsibility for their children and providing their children with two alternate homes as equitably as possible.     

The future of clinical practice: A study

This paper presents the results of a study conducted to determine how BSW and MSW social work students differentially assess the relative prestige and effectiveness of casework, psychotherapy, and private practice in relation to thirteen other social work methods, and to ascertain what methods they would ideally like to practice upon graduation from their respective programs. The results indicate that undergraduate and graduate students view the average prestige and effectiveness of the three clinical methods quite differently. Also, the results reveal a very low correlation between what methods the students would like to practice and how they assess their prestige and effectiveness.     

An Exact Analysis of the Multistage Model Explaining Dose-Response Concavity

The traditional multistage (MS) model of carcinogenesis implies several empirically testable properties for dose-response functions. These include convex (linear or upward-curving) cumulative hazards as a function of dose; symmetric effects on lifetime tumor probability of transition rates at different stages; cumulative hazard functions that increase without bound as stage-specific transition rates increase without bound; and identical tumor probabilities for individuals with identical parameters and exposures. However, for at least some chemicals, cumulative hazards are not convex functions of dose. This paper shows that none of these predicted properties is implied by the mechanistic assumptions of the MS model itself. Instead, they arise from the simplifying "rare-tumor" approximations made in the usual mathematical analysis of the model. An alternative exact probabilistic analysis of the MS model with only two stages is presented, both for the usual case where a carcinogen acts on both stages simultaneously, and also for idealized initiation-promotion experiments in which one stage at a time is affected. The exact two-stage model successfully fits bioassay data for chemicals (e.g., 1,3-butadiene) with concave cumulative hazard functions that are not well-described by the traditional MS model. Qualitative properties of the exact two-stage model are described and illustrated by least-squares fits to several real datasets. The major contribution is to show that properties of the traditional MS model family that appear to be inconsistent with empirical data for some chemicals can be explained easily if an exact, rather than an approximate model, is used. This suggests that it may be worth using the exact model in cases where tumor rates are not negligible (e.g., in which they exceed 10%). This includes the majority of bioassay experiments currently being performed.     

A meta-analysis of research on adolescent contraceptive use

Meta-analysis was used to summarize the results of 134 studies of adolescent contraceptive use in relation to two major explanatory models, the career model and the decision model. There was evidence in support of both models, although there has been less research conducted on variables related to the decision model. The major variables found to affect young women's contraceptive use were partner influence to use contraception, acceptance of one's sexuality, future orientation, positive attitudes toward contraception, an exclusive sexual relationship, and frequency of intercourse. The major variables affecting young men's contraceptive use were partner influence, frequency of intercourse, and positive attitudes toward contraception; however, there was relatively little research on young men compared to young women. A number of possible future directions for research are noted.We would like to thank Nancy Adler and Catherine Chilman for their comments on an earlier version of this article. Portions of this research were presented at the 1984 meeting of the American Psychological Association.Requests for reprints should be addressed to Bernard E. Whitley, Jr., Department of Psychological Science, Ball State University, Muncie, Indiana, 47306.     

The odyssey of the immigrant in American history: From the changed to the changer. A bibliographic essay

This essay examines the work of nine contemporary historians who have reacted to the model of immigration associated with the work of Oscar Handlin. Some of these writers have composed variations on Handlin's work: others have opposed it. Their findings and interpretations have profoundly altered the historiography of immigration into America.