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This article presents the research papers published in this issue of the journal "Rural Sociology." The first paper by James H. Copp represents a stage in the maturation of research on farm practice acceptance. It is one of the first attempts to compare the results of studies conducted in different agricultural regions. Using data from Wilkening's study in Wisconsin and from his own study in Kansas, he developed comparable measures of certain personal, social, and economic variables. Another paper by Copp and colleagues deals with the informational aspect of the acceptance of new farm practices. They attempt essentially to specify the function of information sources in the adoption process. By asking a series of questions about the sources of information at various times, from the awareness of a new practice until its adoption, they find that institutionalized sources tend to perform a function separate from that of noninstitutionalized sources. The study by Charles R. Hoffer and Dale Stangland is a worthy attempt to take into account the farmer's value orientations as they affect his adoption of practices.

The purpose of this paper is the analysis of the interactional patterns of Wisconsin farm couples with their parents. Step-wise multiple regression analysis provides a technique to solve a sequence of one or more multiple linear models by step-wise application of the least sum-of-squares method. The predictor variables used in this analysis include: distance, husband's age, stage in the family life-cycle, husband's education, wife's education, gross farm income, agricultural training of the husband, productive-man-work-units, and level of living. The results showed that distance is an important factor in the interaction between generations in rural areas. [ABSTRACT FROM AUTHOR]

A 1-D full-life-cycle, Individual-based model (IBM), two-way coupled with a hydrodynamic/biogeochemical model, is demonstrated for anchovy and sardine in the N. Aegean Sea (Eastern Mediterranean). The model is stage-specific and includes a ‘Wisconsin’ type bioenergetics, a diel vertical migration and a population dynamics module, with the incorporation of known differences in biological attributes between the anchovy and sardine stocks. A new energy allocation/egg production algorithm was developed, allowing for breeding pattern to move along the capital-income breeding continuum. Fish growth was calibrated against available size-at-age data by tuning food consumption (the half saturation coefficients) using a genetic algorithm. After a ten-years spin up, the model reproduced well the magnitude of population biomasses and spawning periods of the two species in the N. Aegean Sea. Surprisingly, model simulations revealed that anchovy depends primarily on stored energy for egg production (mostly capital breeder) whereas sardine depends heavily on direct food intake (income breeder). This is related to the peculiar phenology of plankton production in the area, with mesozooplankton concentration exhibiting a sharp decrease from early summer to autumn and a subsequent increase from winter to early summer. Monthly changes in somatic condition of fish collected on board the commercial purse seine fleet followed closely the simulated mesozooplankton concentration. Finally, model simulations showed that, when both the anchovy and sardine stocks are overexploited, the mesozooplankton concentration increases, which may open up ecological space for competing species. The importance of protecting the recruit spawners was highlighted with model simulations testing the effect of changing the timing of the existing 2.5-months closed period. Optimum timing for fishery closure is different for anchovy and sardine because of their opposite spawning and recruitment periods. [ABSTRACT FROM AUTHOR]