Integration between the epibranchial placodes and the hindbrain

Developmental integration results from coordination among components of different embryonic fields to realize the later anatomical and functional relationships. We demonstrate that in the chick head, integration between the epibranchial placodes and the hindbrain is achieved as the neuroglial hindbrain crest cells guide the epibranchial neuronal cells inward to establish their central connections. This work defines a role for the neuroglial hindbrain crest in organizing the afferent innervation of the hindbrain.     

beta -Helical polymers from isocyanopeptides

Polymerization of isocyanopeptides results in the formation of high molecular mass polymers that fold in a proteinlike fashion to give helical strands in which the peptide chains are arranged in beta-sheets. The beta-helical polymers retain their structure in water and unfold in a cooperative process at elevated temperatures. The peptide architecture in these polymers is a different form of the beta-helix motif found in proteins. Unlike their natural counterparts, which contain arrays of large beta-sheets stacked in a helical fashion, the isocyanopeptide polymers have a central helical core that acts as a director for the beta-sheet-like arrangement of the peptide side arms. The helical structure of these isocyanopeptide polymers has the potential to be controlled through tailoring of the side branches and the hydrogen-bonding network present in the beta-sheets.     

Efficacy of using roncoleukin in combined therapy of experimental trichinellosis in mice

It is established on a model of experimental trichinellosis in mice that roncoleukin (rIL2) in a dose of 10000 IU/kg causes an increase in nonspecific resistance of the organism to invasion. A tendency of potentiation of the anthelmintic action of albendazole and reliable increase of the level of specific antibodies in blood serum is revealed when roncoleukin is prescribed together with specific drug.     

Animal versus wind dispersal and the robustness of tree species to deforestation

Studies suggest that populations of different species do not decline equally after habitat loss. However, empirical tests have been confined to fine spatiotemporal scales and have rarely included plants. Using data from 89,365 forest survey plots covering peninsular Spain, we explored, for each of 34 common tree species, the relationship between probability of occurrence and the local cover of remaining forest. Twenty-four species showed a significant negative response to forest loss, so that decreased forest cover had a negative effect on tree diversity, but the responses of individual species were highly variable. Animal-dispersed species were less vulnerable to forest loss, with six showing positive responses to decreased forest cover. The results imply that plant-animal interactions help prevent the collapse of forest communities that suffer habitat destruction.     

Inter- and intraspecies contamination of human breast tumor cell lines HBC and BrCa5 and other cell cultures

It is shown that the two most recently reported cell lines derived from malignant human breast tissue, HBC and BrCa5 are, respectively, rat and HeLa cell contaminants. The incidence of inter- and intraspecies contamination among 279 cell cultures from 45 laboratories in an 18-month survey is also presented.     

Osmotically induced changes in electrical properties of plant protoplast membranes

The internal electrical potential of protoplasts from six different plant species was positive. Plasmolyzed cells of leaves had positive voltages of similar magnitude. Both Elodea leaf cells and tobacco protoplasts with regenerated cell walls became more electronegative during deplasmolysis. These findings suggest that cell turgor affects membrane components that determine cellular potential.     

New memory technologies

Computers today use a hierarchy of large-capacity, relatively slow mechanically accessed memories in conjunction with fast electronically accessed memories of relatively small capacity. While the gap between these is spanned by ingenious organizations and programming, it would be highly desirable to fill it instead by some device of sufficient capacity and speed. Candidates for gap-filling memories include metal oxide semiconductor (MOS) random-access memories (RAM's) made by large-scale integration (LSI); charge-coupled devices; magnetic bubble devices based on cylindrical domains of magnetization; electron beam-addressed memories; and optical memories based on lasers, holography, and electrooptical effects. At present, the MOS RAM is the prime contender. Its natural evolution and the evolution of magnetic-recording techniques on which mass storage is based are likely to continue to shape the future as they have for more than a decade. On the other hand, radically new technologies, still at an early laboratory stage, are aimed at a more ideal solution than today's hierarchy.