Sequence-selective assembly of tweezer-molecules on linear templates enables frameshift-reading of sequence information

Monomer-sequence information in synthetic copolyimides can be recognised by tweezer-type molecules binding to adjacent triplet-sequences on the polymer chains. In the present paper different tweezer-molecules are found to have different sequence-selectivities, as demonstrated in solution by 1H NMR spectroscopy and in the solid state by single crystal X-ray analyses of tweezer-complexes with linear and macrocyclic oligo-imides. This work provides clear-cut confirmation of polyimide chain-folding and adjacent-tweezer-binding. It also reveals a new and entirely unexpected mechanism for sequence-recognition which, by analogy with a related process in biomolecular information processing, may be termed "frameshift-reading". The ability of one particular tweezer-molecule to detect, with exceptionally high sensitivity, long-range sequence-information in chain-folding aromatic copolyimides, is readily explained by this novel process

Mercury in the feathers of bird scavengers from two areas of patagonia (Argentina) under the influence of different anthropogenic activities: A preliminary study

Mercury (Hg) is a global pollutant that bioaccumulates and biomagnifies in food chains and is associated with adverse effects in both humans and wildlife.We used feather samples from bird scavengers to evaluate Hg concentrations in two different areas of Northern Patagonia. Hg concentrations were analyzed in feathers obtained from turkey vultures (Cathartes aura), Black Vultures (Coragyps atratus), and southern crested caracaras (Caracara plancus) from the two areas of Northern Patagonia (Argentina): Bariloche and El Valle. Hg was detected in all the samples analyzed, but the concentrations can be considered low for the three species in both sampling areas. The mean concentration of Hg in Bariloche was 0.22 ± 0.16 mg/kg dry weight (d.w.) in black vulture, 0.13 ± 0.06 mg/kg d.w. in turkey vulture, and 0.13 ± 0.09 mg/kg d.w. in southern crested caracara; in El Valle, the mean concentration of Hg was 1.02 ± 0.89 mg/kg d.w. in black vulture, 0.53 ± 0.82 mg/kg d.w. in turkey vulture, and 0.54 ± 0.74 mg/kg d.w. in southern crested caracara. Hg concentrations in feathers were explained by the sampling area but not by the species. The concentrations of Hg contamination were comparable to those obtained in other studies of terrestrial raptors and aquatic bioindicator raptors. The species of the present study occur throughout much of North and South America. Thus, they may be appropriate bioindicators across the species’ range, which is particularly useful as a surrogate, especially in distribution areas shared with endangered scavengers such as the California condor (Gymnopsys californianus) and the Andean Condor (Vultur gryphus).Fil: Di Marzio, Alessandro. Universidad de Murcia; EspañaFil: Gómez Ramírez, Pilar. Universidad de Murcia; EspañaFil: Barbar, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: García Fernández, Antonio Juan. Universidad de Murcia; EspañaFil: Martínez López, Emma. Universidad de Murcia; Españ