173 research outputs found

    Functionality of In vitro Reconstituted Group II Intron RmInt1-Derived Ribonucleoprotein Particles

    Get PDF
    The functional unit of mobile group II introns is a ribonucleoprotein particle (RNP) consisting of the intron-encoded protein (IEP) and the excised intron RNA. The IEP has reverse transcriptase activity but also promotes RNA splicing, and the RNA-protein complex triggers site-specific DNA insertion by reverse splicing, in a process called retrohoming. In vitro reconstituted ribonucleoprotein complexes from the Lactococcus lactis group II intron Ll.LtrB, which produce a double strand break, have recently been studied as a means of developing group II intron-based gene targeting methods for higher organisms. The Sinorhizobium meliloti group II intron RmInt1 is an efficient mobile retroelement, the dispersal of which appears to be linked to transient single-stranded DNA during replication. The RmInt1IEP lacks the endonuclease domain (En) and cannot cut the bottom strand to generate the 3â€Č end to initiate reverse transcription. We used an Escherichia coli expression system to produce soluble and active RmInt1 IEP and reconstituted RNPs with purified components in vitro. The RNPs generated were functional and reverse-spliced into a single-stranded DNA target. This work constitutes the starting point for the use of group II introns lacking DNA endonuclease domain-derived RNPs for highly specific gene targeting methods.This work was supported by research grant BIO2014-51953-P of the Plan Nacional de I+D+i, Biotechnology program from the Spanish Ministerio de EconomĂ­a y Competitividad including ERDF (European Regional Development Funds).Peer reviewedPeer Reviewe

    Prediction of adult conformation traits from shape characteristics of Pura Raza Español foals.

    Get PDF
    NÂș ArtĂ­culo 104701Horse conformation has been proposed as an indirect indicator of performance, since their genetic correlations are often positive and high. In Pura Raza Espa ̃nol (PRE) horses, the selection of conformation traits more related to functionality and performance allows a pre-selection of animals and contributes towards saving costs and increasing the genetic progress. The aim of this paper is to evaluate the predictability of 16 conformation traits (14 body measurements and 2 linear conformation traits) in adult PRE horses, focusing on the conformation traits of foals. The dataset included 155,716 records (82,408 young and 73,308 adult horses) with conformation traits from 142,244 different horses, aged between 1-36 years old. Animals between 1-3 years old were included in the ‘young’ group and older animals in the ‘adult’ group. A univariate General Linear Model procedure fol- lowed by a Tukey-post-hoc test were used to assess the statistical significance of non-genetic effects. Heritability values were estimated univariately. The fitted models included breeder, age and inbreeding (F) as covariates, and sex and coat colour as fixed effects. Coat colour and F were significant for 75% and 87.5% of the traits analysed, respectively; and the other effects analysed were significant for all the conformation traits. Heritability values ranged between 0.178±0.0063 and 0.795±0.0098 in young horses, and between 0.273±0.0038 and 0.894±0.0007 in adult horses. The genetic correlations of the conformation traits between young and adult horses were above 0.75 for 93.75% of the conformation traits analysed, which confirms the efficiency of pre- selection in young horses based on conformation features to predict their adult performance

    Influence of the feedstock characteristics on the microstructure and properties of Al2O3 TiO2 plasma-sprayed coatings

    Get PDF
    [EN] Atmospheric plasma spraying (APS) is an interesting technique to obtain nanostructured coatings due to its versatility, simplicity and relatively low cost. However, nanometric powders cannot be fed into the plume using conventional feeding systems, due to their low mass and poor flowability, and must be adequately reconstituted into sprayable micrometric agglomerates. In this work, Al2O3–13 wt.%TiO2 nanostructured and submicron-nanostructured powders were deposited using APS. The feedstocks were obtained by spray drying from two starting suspensions, prepared by mixing two commercial nanosuspensions of Al2O3 and TiO2, or by adding nanosized TiO2 and submicron-sized Al2O3 powders to water. The spray-dried granules were heat-treated to reduce their porosity and the resultant powders were fully characterized. Optimization of the deposition conditions enabled the reconstituted powders to be successfully deposited, yielding coatings that were well bonded to the substrate. The coating microstructure, characterized by SEM, was formed by semi-molten feedstock agglomerates surrounded by fully molten particles that act as a binder. Moreover, microhardness, adhesion, and tribological behavior were determined, and the impact of the granule characteristics on these properties was studied. It was found that changing the feedstock characteristics allowed controlling the coating quality and properties.This work has been supported by the Spanish Ministry of Science and Innovation (project MAT2009-14144-C03).Vicent, M.; Bannier, E.; Benavente Martínez, R.; Salvador Moya, MD.; Molina, T.; Moreno, R.; Sánchez, E. (2013). Influence of the feedstock characteristics on the microstructure and properties of Al2O3 TiO2 plasma-sprayed coatings. Surface and Coatings Technology. 220:74-79. https://doi.org/10.1016/j.surfcoat.2012.09.042S747922

    Numerical study and experimental validation of the water films and the detachment of drops on drift eliminators

    Get PDF
    Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health hazards. Generation and control of drift depends mostly on the drift eliminator, a device installed in mechanical cooling towers to prevent the escape of droplets (drift). These eliminators induce a rapid alternation of direction changes, and then the droplets cannot follow the path lines of the airflow within the channels of the eliminator and impact on the plates of it, falling back to the cooling tower ground. This paper focuses on the numerical study of a type of drift eliminator, validated by experimental tests. Three main aspects are considered: the water film formed on the plates of drift eliminators, the size of water droplets detached from this film and the condition of the detachment of these droplets. Good agreement is obtained between numerical and experimental results. The study shows that the behavior of water droplets is very influenced by the air velocity inside the cooling tower.This research is sponsored by the Spanish Government (Projects ENE2010-21679-C02-01 and -02), as well as by the Seneca-Agency for Science and Technology of the Region of Murcia, Spain (Project 15184/PI/10)

    Microstructure and photocatalytic activity of APS coatings obtained from different TiO2 nanopowders

    Full text link
    In recent years, intense research has shown that thermal spray techniques, especially atmospheric plasma spraying (APS), can be used to obtain nanostructured TiO2 coatings with effective photocatalytic activity. This study compares the photocatalytic activity of APS coatings obtained from different powders: two nanostructured TiO2 powders produced by spray-drying of two TiO2 nanosuspensions with different solids contents, one spray-dried powder obtained from a suspension comprising a mixture of submicronic and nanometric TiO2 particles and finally one commercial, nanostructured, TiO2 spray-dried powder. All powders were characterised by XRD, FEG-ESEM, granule size distribution, and a flowability evaluation. Feedstock powders were then deposited on austenitic stainless steel coupons using APS. Hydrogen or helium was used as secondary plasma gas. Coating microstructure and phase composition were characterised using FEG-ESEM and XRD techniques; coating anatase content was quantified by the Rietveld method. A significant amount of anatase to rutile transformation was found to take place during the plasma spraying process. In general, the coatings had a bimodal microstructure characterised by the presence of completely fused areas in addition to non-molten areas consisting of agglomerates of anatase nanoparticles. Results also showed that anatase content and porosity of the coatings largely depend on the secondary plasma gas nature, as well as on the characteristics of the feedstock. Finally the photocatalytic activity of the coatings was determined by measuring the degradation of methylene blue dye in an aqueous solution. A reasonably good fit of a first-order kinetic model to the experimental data was found for all coatings. The values of the kinetic constant were related to feedstock characteristics as well as to plasma spraying conditions. (C) 2012 Elsevier B.V. All rights reserved.Bordes, MC.; Vicent, M.; Moreno, A.; Moreno, R.; Borrell TomĂĄs, MA.; Salvador Moya, MD.; Sanchez, E. (2013). Microstructure and photocatalytic activity of APS coatings obtained from different TiO2 nanopowders. Surface and Coatings Technology. 220:179-186. doi:10.1016/j.surfcoat.2012.08.059S17918622

    Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

    Get PDF
    A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

    Search for the lepton-flavor-violating decays Bs0→e±Ό∓ and B0→e±Ό∓

    Get PDF
    A search for the lepton-flavor-violating decays Bs0→e±Ό∓ and B0→e±Ό∓ is performed with a data sample, corresponding to an integrated luminosity of 1.0  fb-1 of pp collisions at √s=7  TeV, collected by the LHCb experiment. The observed number of Bs0→e±Ό∓ and B0→e±Ό∓ candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(Bs0→e±Ό∓)101  TeV/c2 and MLQ(B0→e±Ό∓)>126  TeV/c2 at 95% C.L., and are a factor of 2 higher than the previous bounds

    Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits

    Full text link
    The WWgamma triple gauge boson coupling parameters are studied using p-pbar -> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were collected with the DO detector from an integrated luminosity of 162 pb^{-1} delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
    • 

    corecore