3,215 research outputs found

    Expected and Unexpected Features of the Newly Discovered Bat Influenza A-like Viruses

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    Citation: Ma, W. J., Garcia-Sastre, A., & Schwemmle, M. (2015). Expected and Unexpected Features of the Newly Discovered Bat Influenza A-like Viruses. Plos Pathogens, 11(6), 6. doi:10.1371/journal.ppat.1004819Influenza A viruses (IAVs) are important zoonotic pathogens that cause epidemic outbreaks in poultry, wild birds, swine, and other mammals. In humans, IAVs cause severe respiratory illness, and zoonotic transmission of IAVs from avian reservoirs poses a constant threat to the public health, as exemplified by the recent outbreak of an avian IAV of the H7N9 subtype [1]. Aquatic birds are considered to be the major reservoir of IAVs, and 16 hemagglutinin (HA) and nine neuraminidase (NA) viral subtypes have been isolated from avian species to date. It is now well documented that from time to time IAVs overcome the species barrier and establish new lineages in other animals, including domestic animals, sea mammals, and humans (Fig 1). Our understanding of IAVs was recently challenged by the identification of two novel genome sequences of influenza A-like viruses from bat specimens by next-generation sequencing. These viruses were provisionally designated "H17N10" (from yellow-shouldered fruit bats [Sturnira lilium] in Guatemala) and "H18N11" (from flat-faced fruit bats [Artibeus planirostris] in Peru) [2,3], which might signal an expansion of IAV host range (Fig 1)

    Differential contribution of PB1-F2 to the virulence of highly pathogenic H5N1 influenza A virus in mammalian and avian species

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    Highly pathogenic avian influenza A viruses (HPAIV) of the H5N1 subtype occasionally transmit from birds to humans and can cause severe systemic infections in both hosts. PB1-F2 is an alternative translation product of the viral PB1 segment that was initially characterized as a pro-apoptotic mitochondrial viral pathogenicity factor. A full-length PB1-F2 has been present in all human influenza pandemic virus isolates of the 20(th) century, but appears to be lost evolutionarily over time as the new virus establishes itself and circulates in the human host. In contrast, the open reading frame (ORF) for PB1-F2 is exceptionally well-conserved in avian influenza virus isolates. Here we perform a comparative study to show for the first time that PB1-F2 is a pathogenicity determinant for HPAIV (A/Viet Nam/1203/2004, VN1203 (H5N1)) in both mammals and birds. In a mammalian host, the rare N66S polymorphism in PB1-F2 that was previously described to be associated with high lethality of the 1918 influenza A virus showed increased replication and virulence of a recombinant VN1203 H5N1 virus, while deletion of the entire PB1-F2 ORF had negligible effects. Interestingly, the N66S substituted virus efficiently invades the CNS and replicates in the brain of Mx+/+ mice. In ducks deletion of PB1-F2 clearly resulted in delayed onset of clinical symptoms and systemic spreading of virus, while variations at position 66 played only a minor role in pathogenesis. These data implicate PB1-F2 as an important pathogenicity factor in ducks independent of sequence variations at position 66. Our data could explain why PB1-F2 is conserved in avian influenza virus isolates and only impacts pathogenicity in mammals when containing certain amino acid motifs such as the rare N66S polymorphism

    Influencia del riego y la fertilización en los esteroles y dialcoholes triterpénicos del aceite de oliva

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    The objective of this work was to evaluate the influence of irrigation and fertilization with nitrogen and potassium on the sterol and triterpene dialcohol contents in two trials of cv. Arbequina in super-intensive orchards in Madrid and Lleida (Spain), using a completely randomized block design. No significant differences in total sterols between deficit and full irrigation treatments were observed. Under very dry conditions, the sterol levels from fully irrigated trees were higher than from rain-fed treatments and the triterpene dialcohol erythrodiol+ uvaol content was lower in the irrigated treatments in Lleida. In the fertilizer trial with full irrigation, total sterols were higher in the two N treatments compared to the unfertilized one; while erythrodiol + uvaol decreased. The application of K fertilizer had no effect on total sterol or triterpene dialcohol contents. A proper fertilization and irrigation are vital to obtain high quality EVOOs that meet the regulatory range in sterol and erythrodiol + uvaol contents.El objetivo de este trabajo fue evaluar la influencia del riego y del abonado nitrogenado y potásico en los esteroles y los dialcoholes tritepénicos, en sendos ensayos de arbequina en superintensivo, con un diseño en bloques al azar, en Madrid y Lleida. No se observaron diferencias significativas de esteroles totales entre el riego deficitario y el riego completo. En condiciones de sequía extrema, los esteroles del riego completo fueron superiores al secano y los dialcoholes tritepénicos eritrodiol y uvaol fueron inferiores en los tratamientos de riego en Lleida. En el ensayo de abonado con riego completo, los esteroles totales fueron superiores en las dos aplicaciones de nitrógeno respecto al testigo no tratado y también disminuyeron el eritrodiol + uvaol. El abonado potásico no afectó a los esteroles totales ni a los dihalcoholes triterpénicos. Una fertilización y riego adecuados son de vital importancia para obtener AOVEs de alta calidad que cumplan con los límites legales del contenido en esteroles y eritrodiol + uvaol

    Study soil analysis in Alamo, Temapache and Veracruz, to generate doses of fertilization in orange

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    A nivel mundial los cítricos son el principal frutal cultivado, en México la producción de naranja es de gran importancia económica, los principales municipios productores del estado de Veracruz se encuentran Álamo, Papantla, Martínez de la Torre, Tihuatlán, Chicontepec y Temapache. Estas zonas, mantienen un rendimiento promedio bajo en comparación con otros países productores y un factor que puede mejorar los rendimientos es la óptima fertilización la cual tiene que ser respaldada con análisis de suelos para poder definir una dosis. Se realizaron 646 muestreos de suelo a una profundidad de 30 cm, en el municipio de Temapache, Veracruz, mediante un muestreo aleatorio simple, el tamaño de la muestra se adaptó a las condiciones de cada comunidad. Los análisis fueron enviados a dos laboratorios. Se evaluaron el pH, materia orgánica, nitrógeno, fósforo, potasio. Los resultados se analizaron con estadística no paramétrica mediante un análisis de frecuencias para lo que se plantearon diez rangos, se utilizó R stadistic package versión 64 3.2.0. El pH en más del 70% de los suelos fue alcalino, la concentración de materia orgánica solo en el 34.44% se encontró en condiciones adecuadas, los macroelementos se encuentran en condiciones óptimas a excepción del nitrógeno el cual se presentó en niveles bajos

    Synthesis of the Ti-Silicate Form of BEC Polymorph of B-Zeolite Assisted by Molecular Modeling

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/jp805400u Published Work, see http://pubs.acs.org/page/policy/articlesonrequest/index.html[EN] The K(+) free pure silica form of polymorph C (BEC) of beta-zeolite has been synthesized with a cationic organic structure directing agent (SDA) that was predicted best, out of a series of nine potentials, by means of modeling techniques. On the bases of this synthesis method, the Ti-BEC zeolite has been obtained which owing to the pore topology and dimensions shows a higher epoxidation activity than the Ti-beta-polymorph either with H(2)O(2) or organic peroxides as oxidants.The authors thank the CICYT for financial support (Project MAT 2006-14274-CO2-01). G.S. thanks "Centro de Calculo de la Universidad Politecnica de Valencia" for the use of their computational facilities. M.M. and P.S. thank ITQ for a scholarship. We also thank intramural project CRENATUM.Moliner Marin, M.; Serna Merino, PM.; Cantin Sanz, A.; Sastre Navarro, GI.; Díaz Cabañas, MJ.; Corma Canós, A. (2008). Synthesis of the Ti-Silicate Form of BEC Polymorph of B-Zeolite Assisted by Molecular Modeling. The Journal of Physical Chemistry C. 112(49):19547-19554. https://doi.org/10.1021/jp805400uS19547195541124

    New archaeomagnetic directions from Portugal and evolution of the geomagnetic field in Iberia from Late Bronze Age to Roman Times

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    This study presents new archaeomagnetic results from 33 combustion structures (kilns and hearths) from the archaeological sites of Castelinho, Crestelos, Olival Poço da Barca and Fonte do Milho in NE Portugal. The age of the investigated structures ranges from 1210 BC to 200 AD according to calibrated radiocarbon dating, thermoluminescence dating and archaeological constraints. Stepwise thermal and alternating field demagnetization isolate a single, stable, characteristic remanence component with very well defined directions. Rock magnetic analyses suggest low-Ti titanomagnetite/maghemite as the main magnetic carrier of the remanence. Mean directions are well grouped in most structures. The effect of thermoremanent anisotropy on mean directions has been evaluated and was found to be important. Inclination increases of between 2° and 13° after applying the anisotropy correction at specimen level. This highlights the requirement of evaluating this effect on the directions of small and flattened thin kilns and hearths. The 31 new directional data improve both the temporal and spatial distribution of the Iberian archaeomagnetic dataset from Late Bronze Age to Roman Times. Finally, a new directional palaeosecular variation curve for Iberia for the last twelve centuries BC is proposed. The curve has been computed using the bootstrap method and includes data coming from sites within 900 km of Madrid. The new palaeodirectional secular variation curve for Iberia is consistent with the Western European palaeosecular variation curve and with the prediction of regional European models

    First record of the invasive diatom Didymosphenia geminata (Lyngbye) Schmidt in a Patagonian Andean river of Argentina

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    The Futaleufú River, Argentina, was monitored monthly from June 2010 to August 2011, in order to detect the invasive diatom Didymosphenia geminata, which was previously observed in Chile. Plankton and periphyton samples were taken from 10 sites. Didymosphenia geminata was not found until late winter. In August 2010, the species was first detected at isolated points of the river but in spring and summer the algal coverage extended along several kilometers. The coverage of blooms, spread to deeper areas (pools) with varying depths, reached more than 2 m, invading epiphytic and epilithic substrates. In autumn the bloom diminished its coverage area and there were only small isolated patches. During the next winter, blooms were not observed until late August, when it was recorded again. The observations showed that D. geminata appeared, colonized and invaded the bed of the river at low flow situations in spring and summer and its blooms declined in autumn - when the flows increase - after having been dried in summer when flows were the lowest.Fil: Sastre, Alicia Viviana. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Santinelli, Norma Herminia. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Bauer, Gabriel A.. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel; ArgentinaFil: Ayesterán, M. Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Uyua, Noelia Mariel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; Argentin
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