Could the elongate yellow-orange nostrils of Anguilla bicolor McClelland, 1844 function as fishing lures?

The shortfin eel Anguilla bicolor has elongate, yellow nostrils tipped with orange that protrude forward above the mouth. They are a striking, highly visible feature and it is hypothesised that they function as lures to attract prey, analogous to the illicium and esca of anglerfishes and frogfishes and the lingual appendage of the alligator snapping turtle. Another possible function is as an intraspecific signalling device. The first hypothesis is favoured here.     

Thermo-osmotic gas supply not detected in Avicennia marina seedlings

Ethane was used as tracer gas to assess the likelihood of thermo-osmotically induced mass-flow in the aerenchyma of Avicennia marina seedlings without pneumatophores. Ethane movement was measured in darkness and with illumination at approximately 600 µ mol m^–2s^–1 provided to the leaves and stem, with the expectation that leaf warming under illumination would provide for thermo-osmotic flow. In some seedlings the flow increased with illumination, and in others it either decreased or remained unchanged. Overall, there was no statistically significant difference in the conductance to ethane between darkened illuminated plants, and the rates of ethane movement were consistent with an average diffusive conductance to oxygen down the stem of 0.22 × 10^–19m³ s^–1. it was concluded that there was no evidence for thermo-osmotically induced in this case.     

Comparative structural analysis of the calcium free and bound states of the calcium regulatory protein calbindin D9K

The solution structure of apo calbindin D9K, a member of the calmodulin superfamily of calcium-binding regulatory proteins, has been investigated by 1H nuclear magnetic resonance spectroscopy and the results compared with a corresponding study of the calcium-loaded protein. On the basis of complete sequence-specific assignments, characteristic patterns of short proton-proton distances have been identified in two-dimensional nuclear Overhauser effect spectra, allowing the elements of secondary structure to be determined. It is found that four helices and a short section of antiparallel beta-sheet are present regardless of the calcium content of the protein. In addition, a preliminary analysis of the long-range nuclear Overhauser effects shows that the global folding patterns are the same and that the tertiary structures of the apo protein is very similar to that of the calcium-loaded protein. These results are in stark contrast to a number of very substantial changes in 1H chemical shift. Preliminary studies of protein dynamics show some very large differences in flexibility and internal mobility. This suggests that protein dynamics may play a role more important than was initially realized in the function of calbindin D9K and other homologous calcium-binding regulatory proteins.     

Reducing acetylated tau is neuroprotective in brain injury

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A new precursor for organo-osmium complexes

The use of potassium osmate, K₂[OsO₂(OH)₄], as a precursor for some cyclopentadienyl-osmium complexes is described. The X-ray structures of OsBr(PPh₃)₂Cp, OsCl(dppe)Cp and OsX(dppe)Cp^∗ (X = Cl, Br) are reported.     

Trees on networks: resolving statistical patterns of phylogenetic similarities among interacting proteins

Background  

Phylogenies capture the evolutionary ancestry linking extant species. Correlations and similarities among a set of species are mediated by and need to be understood in terms of the phylogenic tree. In a similar way it has been argued that biological networks also induce correlations among sets of interacting genes or their protein products.