71 research outputs found

    Biosynthesis of Polyunsaturated Fatty Acids in Octopus vulgaris: Molecular Cloning and Functional Characterisation of a Stearoyl-CoA Desaturase and an Elongation of Very Long-Chain Fatty Acid 4 Protein

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    Polyunsaturated fatty acids (PUFAs) have been acknowledged as essential nutrients for cephalopods but the specific PUFAs that satisfy the physiological requirements are unknown. To expand our previous investigations on characterisation of desaturases and elongases involved in the biosynthesis of PUFAs and hence determine the dietary PUFA requirements in cephalopods, this study aimed to investigate the roles that a stearoyl-CoA desaturase (Scd) and an elongation of very long-chain fatty acid 4 (Elovl4) protein play in the biosynthesis of essential fatty acids (FAs). Our results confirmed the Octopus vulgaris Scd is a D9 desaturase with relatively high affinity towards saturated FAs with C18 chain lengths. Scd was unable to desaturate 20:1n-15 (D520:1) suggesting that its role in the biosynthesis of non-methylene interrupted FAs (NMI FAs) is limited to the introduction of the first unsaturation at D9 position. Interestingly, the previously characterised D5 fatty acyl desaturase was indeed able to convert 20:1n-9 (D1120:1) to D5,1120:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5n-3 and thus can contribute to docosahexaenoic acid (DHA) biosynthesis through the Sprecher pathway. Moreover, the octopus Elovl4 was confirmed to play a key role in the biosynthesis of very long-chain (>C24) PUFAs

    G6PD deficiency in Latin America: systematic review on prevalence and variants

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    Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available

    Establecimiento de áreas de protección ambiental y su influencia sobre la planificación regional de la Ciudad de Caracas, Venezuela

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    The Green Belt, since its appearance at the Garden City model by Ebenezer Howard in 1898, was conceived as an unbuilt area surrounding the city, which works as a natural boundary against the urban sprawl. This idea, quickly incorporated in the urban plan for Caracas since 1951, known as the Zona Protectora del Área Metropolitana de Caracas (Protective Zone for the Caracas’ Metropolitan Area), has been used to restrain the uncontrolled growth of Caracas’ urban area.El Green Belt, desde su aparición en la ciudad-jardín de Ebenezer Howard en 1898, concebida como un área no edificada alrededor de la ciudad, ha servido como medio para impedir la dispersión de la ciudad. Esta idea, incorporada en la planificación de la ciudad latinoamericana de Caracas a partir de la década de los cincuenta, bajo el nombre de Zona Protectora del Área Metropolitana de Caracas, tiene la función de contener el crecimiento descontrolado de la mancha urbana de la ciudad

    Política de Aristóteles y sus ciudades (in)finitas

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    En las ciudades griegas de la antigüedad se observa cómo la estructura social intenta adaptarse a su forma urbana. Desde esta perspectiva, en el presente artículo se hace una revisión del pensamiento aristotélico, particularmente desarrollado en la obra Política, a fin de analizar el vínculo entre el orden social ideal griego y su espacio asociado. Para Aristóteles (348-322 a.C.), la forma ideal de la ciudad es un espacio con-tenido, limitado y finito, a fin de evitar el sobrepoblamiento humano y, de esta manera, garantizar su autosuficiencia, belleza, virtud y goberna-bilidad. Primeramente, se presenta la definición de polis griega del filó-sofo estagirita; luego, una breve evolución del concepto de infinitud a través de la historia al partir del planteamiento aristotélico hasta nues-tros días. Es importante mencionar que las reflexiones aquí presentadas representan un primer avance de la investigación histórica desarrollada en torno al proceso de crecimiento urbano y las formas de limitar su ex-pansión física

    Historias violentas: representaciones urbanas de la Ciudad Latinoamericana de Caracas en el arte secuencial

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    The sequential art was developed initially by Wilhem Busch and Rudolf Topfer, European draftsmen, obtaining different perceptions of the city, in his urban andarchitectural form, as well as of the social composition of his citizens. In the Latin- American sequential art, and particularly in the Venezuelan cities, it reflects strongly and clarity every component of the urban Latin-American dynamics.El arte secuencial o cómic, desarrollado inicialmente por los dibujantes europeos Wilhem Busch y Rudolf Topfer, entre otros, permite obtener un registro escrito-visual de las diferentes percepciones de la ciudad, tanto de su forma urbana y arquitectónica, como de la composición social de sus ciudadanos. En el caso latinoamericano, y particularmente en las ciudades venezolanas, aunque es una empresa incipiente en comparación con las industrias americanas y europeas, pero con estilo propio, refleja con fuerza y claridad cada componente de la violenta dinámica urbana latinoamericana
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