Analyzing Collaboration as Drama

The need for inter- and intraorganizational collaboration is ubiquitous. People, groups, and organizations work together at all levels to achieve their ends, sometimes (as in a supply chain) for mutual benefit, at others (as in wage negotiations) to satisfy conflicting needs. Viewing these interactions through the metaphor, not of games but of drama, has led to fresh insights. This paper outlines the analytical theory of drama which has been developed and shows how it can be applied to practical situations. The theory, which can be expressed tightly in the mathematics of set theory, demonstrates how six specific tendencies for a situation to change from the impasse which is arrived at through participants' unresolved differences generates distinctive transformations that lead to a new (and possibly resolvable) situation. It thus moves beyond classical game theory by describing games which change under the internal pressures which they contain.     

Conversion by retinoic acid of anterior cells into ZPA cells in the chick wing bud

In recent years there has been considerable interest in the role of retinoic acid (RA) in vertebrate-limb pattern formation. When RA is applied to the anterior of the chick wing bud, a mirror-image duplication of the limb pattern develops that is identical to the pattern resulting from grafts of posterior tissue (zone of polarizing activity, or ZPA). It has been proposed that position along the anterior-posterior axis in the chick limb is specified by a gradient of a diffusible factor produced by the ZPA. The ZPA-mimicking action of RA has led to the hypothesis that exogenously applied RA acts by providing graded spatial information across the anterior-posterior limb axis. An alternative interpretation is that RA changes anterior cells into ZPA cells, which in turn provide the actual pattern-duplicating stimulus; there is already some preliminary evidence that this occurs. A hybrid interpretation has also been suggested whereby ZPA cells are formed in response to RA exposure and then begin to release retinoids that act as graded spatial cues. We have used a functional assay to test anterior chick wing-bud cells for ZPA activity after exposure to RA. The results of our studies indicate that the action of RA is to change anterior cells into ZPA cells. Further, our results indicate that it is unlikely that RA-treated anterior cells then begin producing RA in such a way as to provide a graded positional signal.     

Fecundity and longevity of houseflies after space flight

After 7 days of space flight house flies, Musca domestica, exhibited similar longevity, but a reduction in reproductive output as compared to earthbound controls. This reduction was not observed in later generations. These data suggest that space flight directly alters the rate of ovarian development, but that this effect is not genetically transmitted.