811 research outputs found

    Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil

    Get PDF
    Citation: Costa, C. R. L., Freitas, M. T. D., Figueiredo, C. A. S., Aragao, N. C., da Silva, L. G., Marcondes, C. B., . . . Balbino, V. D. (2015). Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil. Parasites & Vectors, 8, 9. doi:10.1186/s13071-015-0785-6Background: Even one hundred years after being originally identified, aspects of the taxonomy of the sand fly Lutzomyia longipalpis, the principal vector of Leishmania infantum in the Americas, remain unresolved for Brazilian populations of this vector. The diversity of morphological, behavioral, biochemical, and ethological characters, as well as the genetic variability detected by molecular markers are indicative of the presence of a complex of species. Methods: In this study, a 525 bp fragment of the period gene was used to evaluate sympatric populations of L. longipalpis. A combination of probabilistic methods such as maximum likelihood and genetic assignment approach to investigate sympatric species of L. longipalpis were applied in three populations of Northeast Brazil. Results: Fixed polymorphisms in geographically isolated populations of L. longipalpis from two localities in the state of Ceara and one in the state of Pernambuco, Brazil, was identified in a 525 bp fragment of the gene period (per). Our results suggest a direct relationship between the number of spots found in males' tergites and the genetic variation in cryptic species of L. longipalpis. The fragment used in this study revealed the nature of the ancestral morphotype 1S. Conclusion: New polymorphisms were identified in the gene per which can be used as a genetic barcode to sympatric taxonomy of L. longipalpis. The per gene fragment confirmed the presence of two siblings species of L. longipalpis in Sobral and showed that these same species are present in two other localities, representing an expansion within the L. longipalpis species complex with regards to the states of Ceara and Pernambuco

    Evolução tecnológica e arranjos produtivos de sistemas de integração lavoura-pecuária-floresta no Brasil.

    Get PDF
    Os sistemas agrossilvipastoris, que integram atividades agrícolas, pecuárias e florestais, são considerados, atualmente, inovadores no Brasil, embora vários tipos de plantios associados entre culturas anuais e culturas perenes ou entre frutíferas e árvores madeireiras sejam conhecidos na Europa desde a antiguidade. Vários escritores romanos do século I d.C. ? entre eles, Caio Plínio, que escreveu a enciclopédia intitulada História Natural (Naturalis História ), composta de 37 livros, e Lucius Junius Moderatus, autor com maior repertório documentado sobre a agricultura romana ? fazem referência a sistemas de integração entre árvores, como nogueiras e oliveiras, e pastagens (Dupraz & Liagre, 2008). Outros autores do século VI descrevem sistemas que integram árvores frutíferas com a produção pecuária. O uso desses sistemas, no entanto, quase desapareceu, em virtude, principalmente, da mecanização e da intensificação dos sistemas agrícolas, da dificuldade da colheita manual das frutas e de questões administrativas

    Evolução tecnológica e arranjos produtivos de sistemas de integração lavoura-pecuária-floresta no Brasil.

    Get PDF
    Evolução tecnológica dos sistemas de integração lavoura-pecuária-floresta. Contribuição do sistemas de integração lavoura-pecuária-floresta para a sustentabilidade da agropecuária. Modalidades dos sistemas de integração lavoura-pecuária-floresta. Arranjos regionais de sistemas de integração lavoura-pecuária-floresta. Contribuição da integração lavoura-pecuária-floresta para o sequestro de carbono e a redução da emissão de gases de efeito estufa. Desafios e perspectivas para pesquisa, desenvolvimento e inovação em integração lavoura-pecuária-floresta.Prefácio

    Phlebotomus papatasi SP15: mRNA expression variability and amino acid sequence polymorphisms of field populations

    Get PDF
    Citation: Ramalho-Ortigao, M., Coutinho-Abreu, I. V., Balbino, V. Q., Figueiredo, C. A. S., Mukbel, R., Dayem, H., . . . McDowell, M. A. (2015). Phlebotomus papatasi SP15: mRNA expression variability and amino acid sequence polymorphisms of field populations. Parasites & Vectors, 8, 14. doi:10.1186/s13071-015-0914-2Background: The Phlebotomus papatasi salivary protein PpSP15 was shown to protect mice against Leishmania major, suggesting that incorporation of salivary molecules in multi-component vaccines may be a viable strategy for anti-Leishmania vaccines. Methods: Here, we investigated PpSP15 predicted amino acid sequence variability and mRNA profile of P. papatasi field populations from the Middle East. In addition, predicted MHC class II T-cell epitopes were obtained and compared to areas of amino acid sequence variability within the secreted protein. Results: The analysis of PpSP15 expression from field populations revealed significant intra-and interpopulation variation.. In spite of the variability detected for P. papatasi populations, common epitopes for MHC class II binding are still present and may potentially be used to boost the response against Le. major infections. Conclusions: Conserved epitopes of PpSP15 could potentially be used in the development of a salivary gland antigen-based vaccine.Additional Authors: Lobo, N. F.;Mahon, A. R.;Emrich, S. J.;Kamhawi, S.;Collins, F. H.;McDowell, M. A

    Conceitos e modalidades da estratégia de integração lavoura-pecuária-floresta.

    Get PDF
    bitstream/item/128326/1/ILPF-cap-1.pd

    Conceitos e modalidades da estratégia de integração lavoura-pecuária-floresta.

    Get PDF
    bitstream/item/128326/1/ILPF-cap-1.pd

    A spectroscopy approach to the study of virus infection in the endophytic fungus Epichloë festucae

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In this work we propose a rapid method based on visible and near-infrared (Vis-NIR) spectroscopy to determine the occurrence of double-stranded RNA (dsRNA) viruses in <it>Epichloë festucae </it>strains isolated from <it>Festuca rubra </it>plants. In addition, we examined the incidence of infections by <it>E. festucae </it>in populations of <it>F. rubra </it>collected in natural grasslands of Western Spain.</p> <p>Methods</p> <p>Vis-NIR spectra (400-2498 nm) from 124 virus-infected and virus-free <it>E. festucae </it>isolates were recorded directly from ground and freeze-dried mycelium. To estimate how well the spectra for uninfected and infected fungal samples could be differentiated, we used partial least-squares discriminant analysis (PLS1-DA) and several data pre-treatments to develop calibration models.</p> <p>Results</p> <p>Applying the best regression model, obtained with two sampling years and using standard normal variate (SNV) combined with first derivative transformation to a new validating data set (42 samples), we obtained a correct classification for 75% of the uninfected isolates and up to 86% of the infected isolates.</p> <p>Conclusions</p> <p>The results obtained suggest that Vis-NIR spectroscopy is a promising technology for detection of viral infections in fungal samples when an alternative faster approach is desirable. It provides a tool adequately exact and more time- and cost-saving than the conventional reference analysis.</p

    Shark fossil diversity (Squalomorphii, Squatinomorphii, and Galeomorphii) from the Langhian of Brielas (Lower Tagus Basin, Portugal)

    Get PDF
    The fossiliferous marine Miocene sediments of the Lower Tagus Basin (Portugal) present a great diversity of Chondrichthyes forms. The current study focuses on the fossil sharks from the Langhian Vc unit of the Brielas section, located in the Setúbal Peninsula. A total of 384 isolated fossil teeth were analysed and ascribed to 17 species from the Orders Hexanchiformes, Squaliformes, Squatiniformes, Lamniformes, and Carcharhiniformes. Centrophorus granulosus and Iago angustidens are described for the first time in Portuguese sediments, whereas Pachyscyllium dachiardii and Rhizoprionodon ficheuri represent only their second reported occurrence. Galeorhinus goncalvesi was already known from the Portuguese uppermost Miocene (Alvalade Basin), but it is now recognized in older sediments. Furthermore, the new material seems to include the first reported occurrence of Hexanchus cf. agassizi in Miocene sediments. As a whole, these new findings support the previous palaeoenvironment characterization of a warm infralittoral setting gradually deepening to a circalittoral one, where seasonal upwelling phenomena could have occurred

    Search for a common baryon source in high-multiplicity pp collisions at the LHC

    Get PDF
    We report on the measurement of the size of the particle-emitting source from two-baryon correlations with ALICE in high-multiplicity pp collisions at s=13 TeV. The source radius is studied with low relative momentum p–p, p‾–p‾, p–Λ, and p‾–Λ‾ pairs as a function of the pair transverse mass mT considering for the first time in a quantitative way the effect of strong resonance decays. After correcting for this effect, the radii extracted for pairs of different particle species agree. This indicates that protons, antiprotons, Λ s, and Λ‾ s originate from the same source. Within the measured mT range (1.1–2.2) GeV/c2the invariant radius of this common source varies between 1.3 and 0.85 fm. These results provide a precise reference for studies of the strong hadron–hadron interactions and for the investigation of collective properties in small colliding systems. © 2020 CERN for the benefit of the ALICE CollaborationPeer reviewe
    corecore