CHINs: making the important decisions.

Community health information networks (CHINs) are an evolving concept. In their most basic form, CHINs provide a structure for sharing financial and clinical information among a defined group of entities. However, several key decisions affect how a CHIN will function. Among those decisions are what "community" will be included, what technical infrastructure to use, what organization or group of organizations will lead the CHIN development effort, what types of information will be shared, and how to safe-guard confidentiality.

Characterization of the Heterokaryotic and Vegetative Diploid Phases of MAGNAPORTHE GRISEA.

The heterokaryotic and vegetative diploid phases of Magnaporthe grisea, a fungal pathogen of grasses, have been characterized. Prototrophic heterokaryons form when complementary auxotrophs are paired on minimal medium. Hyphal tip cells and conidia (vegetative spores) taken from these heterokaryons are auxotrophs with phenotypes identical to one or the other of the parents. M. grisea heterokaryons thus resemble those of other fungi that have completely septate hyphae with a single nucleus per cell. Heterokaryons have been utilized for complementation and dominance testing of mutations that affect nutritional characteristics of the fungus. Heterokaryons growing on minimal medium spontaneously give rise to fast-growing sectors that have the genetic properties expected of unstable heterozygous diploids. In fast-growing sectors, most hyphal tip cells are unstable prototrophs. The conidia collected from fast-growing sectors include stable and unstable prototrophs, as well as auxotrophs that exhibit a wide range of phenotypes, including many recombinant classes. Genetic linkage in meiosis has been detected between two auxotrophic mutations that recombine in vegetatively growing unstable diploids. The appearance of recombinants suggests that homologous recombination occurs during vegetative growth of M. grisea. No interstrain barriers to heterokaryosis and diploid formation have been detected. The mating type of the strains that are paired does not influence the formation of heterokaryons or diploids.

Electronic document delivery: directing interlibrary loan traffic through multiple electronic networks.

The University of Nebraska Medical Center (UNMC) uses five different electronic networks for interlibrary loan (ILL) request transmission. The advantages and problems of using electronic networks for ILL request transmission are discussed. Advantages include speed of request transmission, improved capabilities for locating documents, lower labor costs, improved turnaround time, and production of user reports and statistics. Disadvantages include increased work load, additional staff training, coordination of non-standard networks, determining access protocols, and establishing priorities for handling requests.

The impact of on-line search availability on literature retrieval patterns of researchers.

The ready availability of on-line information resources may have resulted in a change in biomedical researchers' patterns of use of resources which are not available on-line. To investigate the occurrence and extent of these changes, the distribution patterns by date of citations from every major article published in ten high-impact biomedical journals in 1959, 1969, and 1979 were analyzed. The analysis showed that in all three time periods approximately 89% of the references fell within fifteen years of the journal's publication date. In 1979, however, references were more evenly distributed over the fifteen years available on-line. In addition, a marked increase was noted in the number of cited references per article. To verify the citation analysis results, a random selection of senior authors of 1979 papers was surveyed. Major findings showed that: (1) approximately 29% of the respondents had used a computer bibliography to prepare the paper which was analyzed; (2) approximately 73% of those using a computer search used it in combination with a manual search; and (3) less than 22% of all respondents had never used a computer-generated bibliography.