41 research outputs found
Lignin repolymerisation in spruce autohydrolysis pretreatment increases cellulase deactivation
This study presents a modified autohydrolysis pretreatment which helps to overcome the recalcitrance of softwood for enzymatic hydrolysis of its cellulose. Autohydrolysis pretreatments of spruce wood were performed with 2-naphthol, which prevents lignin repolymerisation reactions, thereby increasing the enzymatic digestibility of cellulose by up to 64%. The negative influence of repolymerised lignin structures on enzymatic hydrolysis was confirmed by the addition of resorcinol in autohydrolysis, which is known to promote repolymerisation reactions and decreased the biomass digestibility. Several analyses were performed to study the underlying mechanism of this effect on hydrolysis, indicating that cellulolytic enzymes are adsorbed and deactivated especially by repolymerised lignin structures, which accounts for the high differences in biomass digestibility. It was shown that lignin repolymerisation significantly increases its specific surface area through modification of the lignin nanostructure, which is supposed to increase the unproductive binding of enzymes
Avian influenza virus (H11N9) in migratory shorebirds wintering in the Amazon region, Brazil
Aquatic birds are the natural reservoir for avian influenza viruses (AIV). Habitats in Brazil provide stopover and wintering sites for water birds that migrate between North and South America. The current study was conducted to elucidate the possibility of the transport of influenza A viruses by birds that migrate annually between the Northern and Southern Hemispheres. In total, 556 orotracheal/cloacal swab samples were collected for influenza A virus screening using real-time RT-PCR (rRT-PCR). The influenza A virus-positive samples were subjected to viral isolation. Four samples were positive for the influenza A matrix gene by rRT-PCR. From these samples, three viruses were isolated, sequenced and characterized. All positive samples originated from a single bird species, the ruddy turnstone (Arenaria interpres), that was caught in the Amazon region at Caeté Bay, Northeast Pará, at Ilha de Canelas. To our knowledge, this is the first isolation of H11N9 in the ruddy turnstone in South America. (Résumé d'auteur
O uso de praias arenosas com diferentes concentrações humanas por espécies de aves limícolas (Charadriidae e Scolopacidae) neárticas no sudeste do Brasil
Characterization of the geographical distribution pattern of the family Limacinidae Gray, 1840 (Mollusca - Gastropoda) in the waters of Northeastern of Brazil
FIGURE 4 in Four new species and an identification key for Stygodesmodora Blome, 1982 (Nematoda: Spiriniinae) from the continental shelf off northeastern Brazil
FIGURE 4. Stygodesmodora amphidialis sp. n. A Head region of paratype female MNRJ 368; B: Head region of juvenile (J 3); C: Anterior region of juvenile (J 3); D: Anterior region of paratype female MNRJ 368; E: Overview of paratype female MNRJ 368; F: Ovary and vulva opening of paratype female MNRJ 368; G: Tail region of paratype female MNRJ 368
The genus Bolbonema Cobb, 1920 (Nematoda: Desmodoridae): emended diagnosis, key to males, and description of three new species from the continental shelf off northeastern Brazil
Larrazábal-Filho, Alexandre L., Neres, Patrícia F., Esteves, André M. (2018): The genus Bolbonema Cobb, 1920 (Nematoda: Desmodoridae): emended diagnosis, key to males, and description of three new species from the continental shelf off northeastern Brazil. Zootaxa 4420 (4): 551-570, DOI: https://doi.org/10.11646/zootaxa.4420.4.
Study Of SPAI Preconditioners For Convective Problems
In this paper we present an experimental study of SPAI (SParse Aproximation of the Inverse) preconditioners. We are specially interested in the SPAI preconditioners performance for convective problems. Two different techniques to generate SPAI preconditioners are analyzed: those based on the minimisation of the residual matrix norm and those based in the nonsymmetric Lanczos method. The effectivity of both SPAI preconditioners is analyzed in front of the classical incomplete factorisation preconditioners. An elliptic scalar convection-diffusion operator is used to generate the different test cases. As conclusion we determinate that the computational cost of SPAI preconditioners is too large for convective problems. This computational cost makes SPAI preconditioners unusable for practical simulations
CARACTERÍSTICAS DEL SALMÓN MARINADO EN SECO Y POR INMERSIÓN EN DISOLUCIÓN OSMÓTICA CHARACTERISTICS OF THE SALMON MARINATED IN DRY AND FOR IMMERSION IN OSMOTIC SOLUTION
Determination of Bioactive Components in Six Cjilean Red Algae
Poster.-- 17th Euro Fed Lipid Congress: Oils, Fats and lipids: Driving Science and Technology to New Horizons, 20-23 October 2019, SevillePeer reviewe