31 research outputs found

    Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production

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    <p>Abstract</p> <p>Background</p> <p>Wax ester synthases (WSs) can synthesize wax esters from alcohols and fatty acyl coenzyme A thioesters. The knowledge of the preferred substrates for each WS allows the use of yeast cells for the production of wax esters that are high-value materials and can be used in a variety of industrial applications. The products of WSs include fatty acid ethyl esters, which can be directly used as biodiesel.</p> <p>Results</p> <p>Here, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in <it>Saccharomyces cerevisiae</it>. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters) production in <it>S. cerevisiae</it>. All investigated WSs, from <it>Acinetobacter baylyi </it>ADP1, <it>Marinobacter hydrocarbonoclasticus </it>DSM 8798, <it>Rhodococcus opacus </it>PD630, <it>Mus musculus </it>C57BL/6 and <it>Psychrobacter arcticus </it>273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from <it>M. hydrocarbonoclasticus </it>DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production.</p> <p>Conclusions</p> <p>Five WSs from different species were functionally expressed and their substrate preference characterized in <it>S. cerevisiae</it>, thus constructing cell factories for the production of specific kinds of wax ester. WS from <it>M. hydrocarbonoclasticus </it>showed the highest preference for ethanol compared to the other WSs, and could permit the engineered <it>S. cerevisiae </it>to produce biodiesel.</p

    Identificación de riesgos geoambientales y su valoración en la zona de hundimiento del buque Prestige

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    Potential geological hazard assessment has been carried out in the area where the Prestige vessel was sunk using a broad database that comprises: multibeam, high and ultra-high resolution seismic profiles, gravity cores, onland seismicity stations and Ocean Bottom Seismometers (OBS). The main results of this study indicate that among the geologic factors that can be considered as potential hazards, four main categories can be differentiated based on their origin: morphologic, sedimentary, tectonic, and seismicity. Hazards of morphologic origin include steep gradients; the morphologic features suggest the occurrence of mass-wasting instabilities. Hazards of sedimentary origin also includes the occurrence of slope instability processes in form of single slides and a great variety of erosive and depositional gravity flows (debris and turbidity flows). Hazards of tectonic and seismic origin are important because the sinking area straddles the Calida Bank which is a structural seamount with a moderate tectonic activity that results in a latent seismicity of low to moderate magnitude. The interaction of these factors leads to consider to the risk as medium, and the degree of exposure of the bow and stern as high. Several general and specific recommendations are made in order to increase the geological and geophysics knowledgement in the Prestige sinking area and Spanish continental margins and deep sea areas. These recommendations also should be used to elaborate the options for reducing the hazard and loss

    Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

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    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z0.03z\sim 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z0.6z\sim 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July

    Sapientia, 1977, Vol. XXXII, nº 124 (número completo)

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    Contenido: El subjetivismo historicista e irracionalista contemporáneo / Octavio N. Derisi – El ser en Santo Tomás y en la Fenomenología / Vicente O. Ciliberto – La Palabra / Octavio N. Derisi – Ética, teología y religión / Victorino Rodríguez – El poeta del Santísimo Sacramento / Sisto Terán – Notas y comentarios -- Bibliografí

    Influence of Climate and Land Cover/Use Change on Water Balance: An Approach to Individual and Combined Effects

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    Land use/cover change (LUCC) and climate change (CC) affect water resource availability as they alter important hydrological processes. Mentioned factors modify the magnitude of surface runoff, groundwater recharge, and river flow among other parameters. In the present work, changes that occurred in the recent decades at the Quino and Muco river watersheds in the south-central zone of Chile were evaluated to predict future cover/use changes considering a forest expansion scenario according to Chilean regulations. In this way an expansion by 42.3 km2 and 52.7 km2 at Quino and Muco watersheds, respectively, was predicted, reaching a watersheds&rsquo; occupation of 35.4% and 22.3% in 2051. Additionally, the local climatic model RegCM4-MPI-ESM-MR was used considering periods from 2020&ndash;2049 and 2050&ndash;2079, under the RCP 8.5 scenario. Finally, the SWAT model was applied to assess the hydrological response of both watersheds facing the considered forcing factors. Five scenarios were determined to evaluate the LUCC and CC individual and combined effects. The results depict a higher sensitivity of the watersheds to CC impacts, where an increase of evapotranspiration, with a lessening of percolation, surface flow, lateral flow, and groundwater flow, triggered a water yield (WYLD) decrease in all predicted scenarios. However, when both global changes act synergistically, the WYLD decreases considerably with reductions of 109.8 mm and 123.3 mm at the Quino and Muco watersheds, respectively, in the most extreme simulated scenario. This water scarcity context highlights the necessity to promote land use management strategies to counteract the imminent effects of CC in the watersheds

    Eumycetoma caused by Cladophialophora bantiana successfully treated with itraconazole

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    A 57-year-old male presented with dermatosis of the dorsum of the foot consisting of tumefaction, deformity and sinus tract formation. The direct examination of exudates as well as the biopsy tissue, demonstrated the presence of black granules. A dematiaceous fungus was isolated from the lesions and was identified by ribosomal DNA sequencing as Cladophialophora bantiana. This is the second report of this fungus as an etiologic agent of eumycetoma in humans. Clinical and mycologic cure was achieved after 20 months of treatment with itraconazole at a starting dose of 300 mg/day that was tapered during the course of therapy. The patient's isolate had an itraconazole MIC of 0.012g/ml

    Periferias. Revista de Ciencias Sociales (Año XXIII no. 22 primer semestre 2014)

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    El orden capitalista enfrenta nuevamente una crisis mundial y lo hace reforzando la iniciativa por la liberalización económica, contra los trabajadores, la sociedad popular y la naturaleza. Pero a esa iniciativa del capital se le contrapone la diversa iniciativa popular, la que construye un nuevo ciclo histórico de lucha de clases luego de la ruptura de la bipolaridad y la pérdida en el imaginario social de mayoría sobre las posibilidades de construir un orden anticolonial, anti-patriarcal, contra la discriminación y el racismo, anticapitalista, antiimperialista y por el socialismo. Bajo las nuevas condiciones del ciclo de la lucha de clases, éstas, las clases sociales llevan adelante experiencias de nuevo tipo, que hacen evidente la búsqueda de nuevos horizontes de organización de la civilización contemporánea. De estos temas damos cuenta en este número de Periferias, especialmente en el dossier. Junto a las tendencias más generales, pretendemos intervenir en la discusión sobre la conceptualización de las clases sociales y pasar revista a experiencias trascendentes para construir experiencias alternativasEditorial Lucha de clases y clases en lucha Dossier: Lucha de clases y orden capitalista La crisis capitalista y la lucha de clases Julio C. Gambina y Antonio Elías Cuba, bases y complejidades de la politica económica actual José Luis Rodríguez E l Fin de las Clases Sociales en la Teoría Social Brasileña Henrique Amorim El capitalismo del buen salvaje. Nuevo neoliberalismo e inclusión social José Francisco Puello-Socarrás El proceso de distribución del excedente económico y el Estado Emiliano Nicolás Fernández Democracias en juego La revolución bolivariana se juega su destino Modesto Emilio Guerrero México, su larga y tortuosa transición política Carlos Figueroa Ibarra, Giuseppe Lo Brutto y Octavio Humberto Moreno Velador Colaboraciones El cumpleaños de Rodolfo Walsh y la cuestión Milani Polemizando con Ricardo Forster sobre la ética y la política José Ernesto Schulman Comentario de libros Mario Hernández. El movimiento de autogestión obrera en Argentina. Empresas recuperadas y movimientos de trabajadores desocupados Sergio Pap
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