49 research outputs found

    Transition-metal-free cross-coupling of indium organometallics with chromene and isochroman acetals mediated by BF3·OEt2

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    [Abstract] A transition-metal-free coupling of triorganoindium reagents with benzopyranyl acetals mediated by a Lewis acid has been developed. The reaction of R3In with chromene and isochroman acetals in the presence of BF3·OEt2 afforded 2-substituted chromenes and 1-substituted isochromans, respectively, in good yields. The reactions proceed with a variety of triorganoindium reagents (aryl, heteroaryl, alkynyl, alkenyl, alkyl) using only 50 mol % of the organometallic, thus demonstrating the efficiency of these species. Preliminary mechanistic studies indicate the formation of an oxocarbenium ion intermediate in the presence of the Lewis acid.Ministerio de Economía y Competitividad; CTQ2012-31200Ministerio de Economía y Competitividad; CTQ2015-68369-

    Synthesis of bench-stable solid triorganoindium reagents and reactivity in palladium-catalyzed cross-coupling reactions

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    [Abstract] Bench-stable solid triorganoindium compounds have been prepared by coordination with 4-(dimethylamino)pyridine (DMAP). The solid R3In(DMAP) complexes are obtained from the corresponding solution of R3In in quantitative yield and can be stored for up to several weeks. These reagents show excellent reactivity in palladium-catalyzed cross-coupling reactions with organic electrophiles.Ministerio de Economía y Competitividad; CTQ2015-68369-PGalicia. Consellería de Cultura, Educación e Ordenación Universitaria; GRC2014/04

    clustcurv: An R Package for Determining Groups in Multiple Curves

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    In many situations, it could be interesting to ascertain whether groups of curves can be performed, especially when confronted with a considerable number of curves. This paper introduces an R package, known as clustcurv, for determining clusters of curves with an automatic selection of their number. The package can be used for determining groups in multiple survival curves as well as for multiple regression curves. Moreover, it can be used with large numbers of curves. An illustration of the use of clustcurv is provided, using both real data examples and artificial data.The authors acknowledge financial support by the Spanish Ministry of Economy and Competitiveness (MINECO) through project MTM2017-89422-P and MTM2017-82379-R (funded by (AEI/FEDER, UE). Thanks to the Associate Editor and the referee for comments and suggestions that have improved this paper

    seq2R: an R package to detect change points in DNA sequences

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    Identifying the mutational processes that shape the nucleotide composition of the mitochondrial genome (mtDNA) is fundamental to better understand how these genomes evolve. Several methods have been proposed to analyze DNA sequence nucleotide composition and skewness, but most of them lack any measurement of statistical support or were not developed taking into account the specificities of mitochondrial genomes. A new methodology is presented, which is specifically developed for mtDNA to detect compositional changes or asymmetries (AT and CG skews) based on nonparametric regression models and their derivatives. The proposed method also includes the construction of confidence intervals, which are built using bootstrap techniques. This paper introduces an R package, known as seq2R, that implements the proposed methodology. Moreover, an illustration of the use of seq2R is provided using real data, specifically two publicly available complete mtDNAs: the human (Homo sapiens) sequence and a nematode (Radopholus similis) mitogenome sequence.Ministerio de Ciencia e Innovación | Ref. MTM2011-23204Ministerio de Ciencia e Innovación | Ref. PID2020-118101GB-I00Xunta de Galicia | Ref. 10PXIB 300 068 P

    Identification and characterization of esential habitats for three cephalopod species in the national parks of Galician Atlantic Islands and Cabrera

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    31 pages, 16 figures, 8 tables, 1 appendix[EN] We evaluated specific habitat features (bottom substrate type, depth, temperature and season) at random locations in the Cíes archipelago (Galician Atlantic Islands National Park, NW Spain) and to determine their impact on Octopus vulgaris, Sepia officinalis and Loligo vulgaris habitat use. We performed 113 underwater visual transects by scuba diving between April 2012 and August 2015. Habitat features were evaluated as predictors of the presence/absence of spawning dens and egg clusters using Generalized Additive Models. The O. vulgaris spawning essential habitats was found between 5 and 30 m depth in rocky bottoms from Punta Escodelo to Punta Ferreiro (Monteagudo Island), which surface is 6% of the total marine area of the Cíes islands. We propose a complete protection of this area for exploitation. underwater visual transects also showed that there is an O. vulgaris hatchery essential habitat (specimens ≤1000 g) in the sandy bottoms of the Rodas inlet. This small area (2.8% of the total) could be also protected. S. officinalis results revealed two SEH: Bajo de Viños and Piedra del Borrón, hard bottom shoals between 8-13 m covered by sea fans and sea worms and located in the central Cíes islands. We also suggest protecting that small area (0.28% of the total). Very few L. vulgaris eggs masses were found with underwater visual transects and artificial devices attractors in the Cíes islands. Also very few specimens of O. vulgaris and S. officinalis were found with underwater visual transects in Cabrera National Park between 5 and 50 m depth. Two squid spawning essential habitats were located in that park using artificial devices attractors: Na Redona and Ses Rates, both on sandy bottoms from 18 to 50 m depth with fast marine currents. The spawning essential habitats found reveal indicators of three species habitat selection and should help to identify targets for habitat improvement projects and ecosystem management approaches[ES] Mediante 112 censos visuales con escafandra autónoma realizados entre abril de 2012 y agosto de 2015, distribuidos aleatoriamente en el archipiélago de Cíes (Parque Nacional de las Islas Atlánticas de Galicia), se evaluaron las características (tipo de sustrato, profundidad, temperatura y estación) de los hábitats esenciales de Octopus vulgaris, Sepia officinalis y Loligo vulgaris. Dichas características se emplearon como predictores de la presencia/ausencia de guaridas de desove o masas de huevos utilizando Modelos Aditivos Generalizados. El hábitat esencial para el desove de O. vulgaris se localizó entre 5 y 30 m de profundidad en fondos rocosos entre Punta Escodelo y Punta Ferreiro (isla de Monteagudo), cuya superficie es del 6% del total. Proponemos su protección completa para la explotación. Los censos visuales con escafandra autónoma mostraron un hábitat esencial de cría de O. vulgaris en fondos arenosos de la ensenada de Rodas. Esta pequeña área (2,8% del total) podría ser también protegida. Los resultados para S. officinalis revelaron dos HE para el desove: el Bajo de Viños y la Piedra del Borrón, bancos de fondo duro entre 8-13 m cubiertos por gorgonias y poliquetos tubícolas en la ensenada de Rodas. Se sugiere protección para este área (0,28% del total). Apenas se hallaron puestas de L. vulgaris con censos visuales con escafandra autónoma y Dispositivos Atractores de Puesta en Cíes. También se observaron muy escasos ejemplares de S. officinalis y O. vulgaris con censos visuales con escafandra autónoma entre 5 y 50 m de profundidad en el Parque Nacional de Cabrera. Se identificaron dos HE para el desove del calamar en el Parque Nacional de Cabrera usando Dispositivos Atractores de Puesta: Na Redona y Ses Rates, fondos arenosos entre 18 y 50 m de profundidad con rápidas corrientes. Estos HEs son indicadores de selección del hábitat, y constituyen un notable apoyo para identificar objetivos en proyectos de conservación de hábitats y enfoques ecosistémicos en la gestión pesqueraMiguel Cabanellas-Reboredo fue becado por la Conselleria de Educació del Govern de les Illes Balears (Fondo Social Europeo) y actualmente beneficiario de contrato post-doctoral Juan de la Cierva formación (MINECO). Marta Sestelo disfrutó de beca de investigación SFRH/BPD/93928 de Fundacão Ciência e Tecnologia de Portugal y de proyectos del Ministerio de Ciencia e Innovación y la Xunta de Galicia. Este proyecto estuvo financiado por el Organismo Autónomo de Parques Nacionales del Ministerio de Agricultura, Alimentación y Medio Ambiente (CEFAPARQUES, Proyecto número: 458/2011)N

    Statement of Second Brazilian Congress of Mechanical Ventilarion : part I

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    Environmental effects on yield and composition of essential oil in wild populations of spike lavender (Lavandula latifolia medik.)

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    18 Pág.Spike lavender, Lavandula latifolia Medik., is a species of economic importance for its essential oil (EO). The purpose of this study was to estimate the effect of the variable climate and fixed factors such as soil and geographic location on EO yield and quality. The study material was collected in 34 populations from four different Spanish bioregions for three years. The EO extraction from spike lavender leaves and flowers was done with simple hydrodistillation, in Clevenger. Soil samples were also collected. Climate data were provided by the State Meteorological Agency. The EO average yield was obtained for the bioregion mean and in each bioregion. The higher EO yield is related clearly to the climate condition. A greater amount of annual rainfall produced a higher EO yield in the four bioregions and of better quality. Soils richer in organic matter and minerals produced higher EO yield but with less quality. The altitude had little effect on EO yield. Higher altitude favored obtaining higher EO quality. At lower latitude, further south, the populations obtained a higher EO yield. The evaluation of the environmental effect on the EO yield and quality could allow better natural conservation and more accurate selection of the best populations for breeding and spike lavender cultivation protocols.Spanish Ministerio de Economía y Competitividad RTA2012-00057-C03-02 supported the research work.Peer reviewe
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