Stimulation of translation by human Unr requires cold shock domains 2 and 4, and correlates with poly(A) binding protein interaction

The RNA binding protein Unr, which contains five cold shock domains, has several specific roles in post-transcriptional control of gene expression. It can act as an activator or inhibitor of translation initiation, promote mRNA turnover, or stabilise mRNA. Its role depends on the mRNA and other proteins to which it binds, which includes cytoplasmic poly(A) binding protein 1 (PABP1). Since PABP1 binds to all polyadenylated mRNAs, and is involved in translation initiation by interaction with eukaryotic translation initiation factor 4G (eIF4G), we investigated whether Unr has a general role in translational control. We found that Unr strongly stimulates translation in vitro, and mutation of cold shock domains 2 or 4 inhibited its translation activity. The ability of Unr and its mutants to stimulate translation correlated with its ability to bind RNA, and to interact with PABP1. We found that Unr stimulated the binding of PABP1 to mRNA, and that Unr was required for the stable interaction of PABP1 and eIF4G in cells. siRNA-mediated knockdown of Unr reduced the overall level of cellular translation in cells, as well as that of cap-dependent and IRES-dependent reporters. These data describe a novel role for Unr in regulating cellular gene expression

High performance maleated lignocellulose epicarp fibers for copper ion removal

Natural lignocellulosic fiber epicarp extracted from the babassu coconut (Orbignya speciosa) was chemically modified through reaction with molten maleic anhydride without solvent, with incorporation of 189.34 mg g-1 of carboxylic acid groups into the biopolymer structure. The success of this reaction was also confirmed by the presence of carboxylic acid bands at 1741 and 1164 cm-1 in the infrared spectrum. Identically, the same group is observed through 13C NMR CP/MAS in the solid state, via high field signals in the 167 pm region. Both the precursor and the immobilized maleated biopolymers presented nearly the same thermal stability and similar crystallinity to cellulose. However, the pendant carboxylic groups have the ability to remove copper with maximum sorption through a batchwise process at pH 6.0, as expected from the point of zero charge, determined to be 6.45. The sorption kinetic data were fitted to pseudo-first order, pseudo-second order, Elovich-chemisorption and intra-particle diffusion models and the equilibrium data were fitted to the Langmuir, the Freundlich and Tenkim isotherm models. Taking into account a statistical error function and determination coefficients, the data were fit to the pseudo-first and pseudo-second order kinetic and Langmuir isotherm models, with a maximum sorption capacity of copper ions of 55.09 mg g-1. This value suggests the application of this biopolymer with incorporated carboxylate groups as a favorable agent for copper removal from appropriate systems31118319

Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

Background: In inland water systems, it is important to characterize the trophic links in order to identify the ‘trophic species’ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin

Experimental and numerical investigations on the seismic behavior of bridge piers with vertical unbonded prestressing strands

In the performance-based seismic bridge design, piers are expected to undergo large inelastic deformations during severe earthquakes, which in turn can result in large residual drift and concrete crack in the bridge piers. In this paper, longitudinal unbonded prestressing strands are used to minimize residual drift and residual concrete crack width in reinforced concrete (RC) bridge piers. Seven pier specimens were designed and tested quasi-statically and the numerical simulations were carried out. The effectiveness of using vertical unbonded prestressing strands to mitigate the residual drift and concrete crack width of RC bridge piers are examined and discussed in detail. It is found that the residual drift and residual concrete crack width of the piers can be reduced significantly by using the prestressing strands. Moreover, the strands can increase the lateral strength of the piers while have little influence on the ductility capacity of the piers. The hysteretic curves, residual drifts and strand stress of the piers predicted by the numerical model agree well with the testing data and can be used to assess the cyclic behavior of the piers