Heterotrimeric G proteins, consisting of α, β, and γ subunits, couple ligand-bound seven transmembrane domain receptors to the regulation of effector proteins and production of intracellular second messengers. G protein signaling mediates the perception of environmental cues in all higher eukaryotic organisms, including yeast, Dictyostelium, plants, and animals. The nematode Caenorhabditis elegans is the first animal to have complete descriptions of its cellular anatomy, cell lineage, neuronal wiring diagram, and genomic sequence. In a recent paper, Jansen et al.(1) used sequence (...) searches of the C. elegans genome database to identify all heterotrimeric G protein genes (20 Gα, 2 Gβ, 2 Gγ). C. elegans encodes one ortholog of each of the four Gα classes found in metazoans and 16 new Gα genes. The orthologous genes are widely expressed, whereas 14 of the divergent Gα genes are almost exclusively expressed in sensory neurons where they may regulate perception and chemotaxis.BioEssays 21:713–717, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

The authors describe the ethical considerations underlying the inclusion of mental health services into a prioritized health care system. The Oregon Health Plan is a process for defining and delivering basic health services to an entire state. As the plan was developed, the mental health community needed to decide whether or not to participate in the process and, if so, how. Lengthy discussions among mental health consumers, family members, and providers led to a strategy that emphasized the integration of mental (...) health and chemical dependency services into a comprehensive and universal health care program. This approach appears to have achieved relative parity for mental health. (shrink)

This article elaborates the continuing significance of Ricoeur’s development of utopia. Ricoeur develops two not necessarily exclusive aspects of the utopia in its positive sense. First, it acts as an imaginative variation on existing reality, and second, it can act to ‘shatter’ and hence recast existing reality. While Ricoeur himself did not tend to distinguish rigorously between these two senses of the utopia, the article seeks to provide that delineation. Imaginative variation opens the sphere of human possibility but remains hypothetical, (...) while the utopia as that which shatters can introduce a new reality into social existence. In the utopia that shatters, the social imagination can be constitutive of social life. The article situates Ricoeur’s discussion of utopia in his Lectures on Ideology and Utopia in relation to other relevant texts in his corpus, principally The Rule of Metaphor and the forthcoming Lectures on Imagination. The argument locates Ricoeur’s treatment of utopia within the broader field of his work on the symbolic structure of action and social imagination. (shrink)

In the approximation that every inertial observer experiences a homogeneous, uniform flow of time and sees a space that is Euclidean, the arena of physics is Minkowskian and one speed is the same in all intertial frames. If a given intertial observer finds an infinitesimal source or particle traveling faster than this fundamental speed near a given event, the source must appear in some inertial frame spread over neighboring positions at a given time as a spacelike structure. If this structure (...) persists over a period of proper time, it can be interpreted as a wave group. If it is conserved, it can be interpreted as a line or tube of force. (shrink)