504 research outputs found

    Histological biomarkers in gills of Sciades herzbergii (Siluriformes, Ariidae ) caught in the Estuarine Complex of SĂŁo Marcos , MaranhĂŁo

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    ABSTRACT This study aimed to compare an environmental quality of two areas of the estuarine complex of SĂŁo Marcos using gills of changes in Sciades herzbergii as biomarkers of aquatic contamination. Samples were made during the dry season (September/ December 2015) and rainy season (March/ June 2016). They were captured 40 specimens of S. herzbergii at two different points of the estuarine complex: A1) Itaqui port (potentially contaminated area); A2) IgarapĂ© do Puca, AlcĂąntara (control area). Abiotic variables were recorded: salinity, temperature, pH and dissolved oxygen. In the laboratory, the gills of each species were fixed in 10% formaldehyde and kept in 70% alcohol until the usual histological technique was performed. The gill alterations identified in the fish of the potentially contaminated area were: epithelial displacement (DE), congestion (CO), aneurysm (AN), lamellar fusion (FL), hyperplasia (HI), capillary dilation (DC), necrosis and epithelial cell proliferation (PCE). The changes in the control region were: epithelial displacement (DE), lamellar fusion (FL), necrosis (NE) and epithelial cell proliferation (PCE). Gill alterations were more frequent in the port region (84%) than in the control region (16%). These results indicate that fish from the potentially contaminated area are presenting biological responses to local stress.Neste estudo, objetivou-se avaliar a qualidade ambiental de duas ĂĄreas do complexo estuarino de SĂŁo Marcos, utilizando-se as alteraçÔes branquiais em Sciades herzbergii como biomarcadores de contaminação aquĂĄtica. Foram realizadas coletas no perĂ­odo de estiagem (setembro/dezembro de 2015) e no perĂ­odo chuvoso (março/junho de 2016). Foram capturados 40 exemplares de S. herzbergii em dois locais distintos do complexo estuarinoA1) Porto do Itaqui Bacanga (ĂĄrea potencialmente impactada); A2) IgarapĂ© do Puca, AlcĂąntara (ĂĄrea controle). Foram registradas as variĂĄveis abiĂłticassalinidade, temperatura, pH e oxigĂȘnio dissolvido. No laboratĂłrio, as brĂąnquias de cada espĂ©cime foram fixadas em formol a 10% e mantidas em ĂĄlcool a 70% atĂ© a execução da tĂ©cnica histolĂłgica usual. As alteraçÔes branquiais identificadas nos peixes da ĂĄrea potencialmente contaminada foramdeslocamento do epitĂ©lio (DE), congestĂŁo (CO), aneurisma (AN), fusĂŁo lamelar (FL), hiperplasia (HI), dilatação capilar (DC), necrose (NE) e proliferação de cĂ©lulas epiteliais (PCE). As alteraçÔes na regiĂŁo controle foramdeslocamento do epitĂ©lio (DE), fusĂŁo lamelar (FL), necrose (NE) e proliferação de cĂ©lulas epiteliais (PCE). As alteraçÔes branquiais foram mais frequentes na regiĂŁo portuĂĄria (84%) do que na regiĂŁo controle (16%). Esses resultados indicam que os peixes da ĂĄrea potencialmente contaminada estĂŁo apresentando respostas biolĂłgicas ao estresse local

    Production of fructo-oligosaccharides by Aspergillus ibericus and their chemical characterization

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    A great demand for prebiotics is driving the search for new sources of fructo-oligosaccharides (FOS) producers and for FOS with differentiated functionalities. In the present work, FOS production by a new isolated strain of Aspergillus ibericus was evaluated. The temperature of fermentation and initial pH were optimized in shaken flask to yield a maximal FOS production, through a central composite experimental design. FOS were produced in a one-step bioprocess using the whole cells of the microorganism. The model (R2 = 0.918) predicted a yield of 0.56, experimentally 0.53 ± 0.03 gFOS.ginitial sucrose1 was obtained (37.0 °C and a pH of 6.2). A yield of 0.64 ± 0.02 gFOS.ginitial sucrose1 was obtained in the bioreactor, at 38 h, with a content of 118 ± 4 g.L1 in FOS and a purity of 56 ± 3%. The chemical structure of the FOS produced by A. ibericus was determined by HPLC and NMR. FOS were identified as 1-kestose, nystose, and 1F-fructofuranosylnystose. In conclusion, A. ibericus was found to be a good alternative FOS producer.Clarisse Nobre acknowledges the Portuguese Foundation forScience and Technology (FCT) for her Post-Doc Grant [ref. SFRH/BPD/87498/ 2012] and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124FEDER-027462), the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684), BioTecNorte operation(NORTE-01-0145-FEDER-000004) and the project MultiBioreïŹnery (POCI-01-0145-FEDER-016403) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    ExpressĂŁo da esterilidade feminina e da carpeloidia em mamoeiro sob diferentes ambientes de cultivo protegido.

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    O presente estudo teve por objetivo avaliar a ocorrĂȘncia de esterilidade feminina e de carpeloidia em mamoeiros hermafroditas 'Baixinho-de-Santa AmĂĄlia' cultivados sob manejo orgĂąnico, em diferentes tipos de ambiente de proteção,e conduzido com ou sem bifurcação do tronco no transcorrer das quatro estaçÔes do ano. Foram construĂ­dos trĂȘs tipos de estruturas de proteção contĂ­guas: (i) estufa (cobertura de plĂĄstico); (ii) estufa sombreada (cobertura adicional de tela 'sombrite' - 30% sobre o plĂĄstico), e (iii) telado (cobertura exclusiva de tela 'sombrite' - 30%), ao lado de uma ĂĄrea de ambiente natural, a pleno sol. Nestes locais, foram cultivados, dentro das normas tĂ©cnicas da agricultura orgĂąnica, mamoeiros da cv. Baixinho-de-Santa-AmĂĄlia. Em metade das plantas, abrangendo todos os ambientes de cultivo, a gema apical foi incisada, logo apĂłs a sexagem, visando Ă  bifurcação do tronco. Para efeito de anĂĄlise de variĂąncia, foram considerados quatro blocos por ambiente de cultivo, tendo cada bloco trĂȘs repetiçÔes relativas ao modo de condução das plantas (com e sem bifurcação do tronco). Para anĂĄlise estatĂ­stica, procedeu-se Ă  "anĂĄlise conjunta de experimentos", no caso, os ambientes de cultivo. Nos mamoeiros com tronco bifurcado, houve diminuição do nĂșmero de frutos carpeloides e aumento do nĂșmero de flores fĂȘmeas estĂ©reis. No entanto, essa bifurcação nĂŁo influenciou a frequĂȘncia de frutos normais. Durante a primavera (setembro a dezembro), e notadamente na estufa, o maior nĂșmero de frutos carpeloides por planta correlacionou-se a temperaturas mais elevadas, maior amplitude tĂ©rmica e maior vigor vegetativo; jĂĄ, a maior ocorrĂȘncia de flores estaminadas correlacionou-se tambĂ©m a temperaturas elevadas, baixa luminosidade e menor vigor vegetativo. Por outro lado, essas mesmas condiçÔes ambientais e fenolĂłgicas favorĂĄveis Ă  carpeloidia aumentaram a quantidade de frutos normais, assim contribuindo positivamente para a produtividade do mamoeiro

    Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

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    The elliptic, v2v_2, triangular, v3v_3, and quadrangular, v4v_4, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range ∣η∣<0.8|\eta|<0.8 at different collision centralities and as a function of transverse momentum, pTp_{\rm T}, out to pT=20p_{\rm T}=20 GeV/cc. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for pT>8p_{\rm T}>8 GeV/cc. The small pTp_{\rm T} dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to pT=8p_{\rm T}=8 GeV/cc. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least pT=8p_{\rm T}=8 GeV/cc indicating that the particle type dependence persists out to high pTp_{\rm T}.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

    Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

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    The inclusive transverse momentum (pTp_{\rm T}) distributions of primary charged particles are measured in the pseudo-rapidity range ∣η∣<0.8|\eta|<0.8 as a function of event centrality in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}}=2.76 TeV with ALICE at the LHC. The data are presented in the pTp_{\rm T} range 0.15<pT<500.15<p_{\rm T}<50 GeV/cc for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor RAAR_{\rm{AA}} using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-pTp_{\rm T} particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with RAA≈0.13R_{\rm{AA}}\approx0.13 at pT=6p_{\rm T}=6-7 GeV/cc. Above pT=7p_{\rm T}=7 GeV/cc, there is a significant rise in the nuclear modification factor, which reaches RAA≈0.4R_{\rm{AA}} \approx0.4 for pT>30p_{\rm T}>30 GeV/cc. In peripheral collisions (70-80%), the suppression is weaker with RAA≈0.7R_{\rm{AA}} \approx 0.7 almost independently of pTp_{\rm T}. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

    Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

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    The pTp_{\rm T}-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D0^0, D+^+, and D∗+^{*+} in the rapidity range ∣y∣<0.5|y|<0.5, and for transverse momentum 1<pT<121< p_{\rm T} <12 GeV/cc, were measured in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D0→^0 \rightarrow Kπ\pi, D+→^+ \rightarrow Kππ\pi\pi, D∗+→^{*+} \rightarrow D0π^0\pi, and their charge conjugates, and was performed on a Lint=1.1L_{\rm int} = 1.1 nb−1^{-1} event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at s=2.76\sqrt{s} = 2.76 TeV and at 7 TeV was evaluated by extrapolating to the full phase space the pTp_{\rm T}-differential production cross sections at s=2.76\sqrt{s} = 2.76 TeV and our previous measurements at s=7\sqrt{s} = 7 TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
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