125 research outputs found

    Propiedades residuales y problemas de decisión en grupos

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    El propósito del trabajo es introducir los problemas clásicos de decisión en la teoría de grupos haciendo un especial hincapié en el problema de la palabra para grupos policíclicos

    Adaptations in energy metabolism and gene family expansions revealed by comparative transcriptomics of three Chagas disease triatomine vectors

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    Background: Chagas disease is a parasitic infection caused by Trypanosoma cruzi. It is an important public health problem affecting around seven to eight million people in the Americas. A large number of hematophagous triatomine insect species, occupying diverse natural and human-modified ecological niches transmit this disease. Triatomines are long-living hemipterans that have evolved to explode different habitats to associate with their vertebrate hosts. Understanding the molecular basis of the extreme physiological conditions including starvation tolerance and longevity could provide insights for developing novel control strategies. We describe the normalized cDNA, full body transcriptome analysis of three main vectors in North, Central and South America, Triatoma pallidipennis, T. dimidiata and T. infestans. Results: Two-thirds of the de novo assembled transcriptomes map to the Rhodnius prolixus genome and proteome. A Triatoma expansion of the calycin family and two types of protease inhibitors, pacifastins and cystatins were identified. A high number of transcriptionally active class I transposable elements was documented in T. infestans, compared with T. dimidiata and T. pallidipennis. Sequence identity in Triatoma-R. prolixus 1:1 orthologs revealed high sequence divergence in four enzymes participating in gluconeogenesis, glycogen synthesis and the pentose phosphate pathway, indicating high evolutionary rates of these genes. Also, molecular evidence suggesting positive selection was found for several genes of the oxidative phosphorylation I, III and V complexes. Conclusions: Protease inhibitors and calycin-coding gene expansions provide insights into rapidly evolving processes of protease regulation and haematophagy. Higher evolutionary rates in enzymes that exert metabolic flux control towards anabolism and evidence for positive selection in oxidative phosphorylation complexes might represent genetic adaptations, possibly related to prolonged starvation, oxidative stress tolerance, longevity, and hematophagy and flight reduction. Overall, this work generated novel hypothesis related to biological adaptations to extreme physiological conditions and diverse ecological niches that sustain Chagas disease transmission.Fil: Martínez Barnetche, Jesús. Instituto Nacional de Salud Pública; MéxicoFil: Lavore, Andres Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Pergamino); ArgentinaFil: Beliera, Melina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Pergamino); ArgentinaFil: Téllez Sosa, Juan. Instituto Nacional de Salud Pública; MéxicoFil: Zumaya Estrada, Federico A.. Instituto Nacional de Salud Pública; MéxicoFil: Palacio, Victorio Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Pergamino); ArgentinaFil: Godoy Lozano, Ernestina. Instituto Nacional de Salud Pública; MéxicoFil: Rivera Pomar, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Pergamino); ArgentinaFil: Rodríguez, Mario Henry. Instituto Nacional de Salud Pública; Méxic

    Nuevos registros de tigrillo (leopardus wiedii) en San Luis Potosí, México

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    We documented 36 new records of tigrillo in the region Huasteca of San Luis Potosí, México. This new evidence of tigrillo presence augments its range within the state 38 km west. Records were found mainly in areas with dense vegetation cover including tropical forest and tropical deciduous forest. Results of this investigation suggest tigrillo mainly inhabits areas with dense vegetation cover in this region of Mexico

    Polymer materials derived from the SEAr reaction for gas separation applications

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    Producción CientíficaA set of linear polymers were synthesized utilizing an electrophilic aromatic substitution reaction (SEAr) between biphenyl and ketone containing electron-withdrawing groups (isatin, IS; N-methylisatin, MeIS; and 4,5-diazafluoren-9-one, DF). Optimization of the polycondensation reaction was made to obtain high molecular weight products when using DF, which has not previously been used for linear polymer synthesis. Due to the absence of chemically labile units, these polymers exhibited excellent chemical and thermal stability. Linear SEAr polymers were blended with porous polymer networks derived from IS and MeIS, and both neat/mixed materials were tested as membranes for gas separation. The gas separation properties of both pristine polymers and mixed matrix membranes were good, showing some polymer membrane CO2 permeability values higher than 200 barrer

    Traslape espacial de la comunidad de peces dulceacuícolas diurnos en el sistema de humedal Media Luna, Rioverde, S.L.P., México

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    The Media Luna wetland is the most representative and most affected by tourism and management actions in the Llanura de Rioverde, S.L.P. It contains 13 fish species, two of them are nocturnal and eleven diurnal. This study considers only the diurnal species. From these, the most relevant are five local endemic, one native widely distributed and five introduced species. In order to determine the degree of spatial overlap, 54 sub-aquatic transects per sampling session were conducted from 1998 and 1999. The fish population distribution per age class (adult, juvenile and larvae) and the similitude between species pairs were analyzed and estimated for the habitat variables: sector, depth, and vegetation. Adult and juvenile fish tended to overlap for all the variables, whereas the larvae segregated for sector but overlap for depth and vegetation. There was a high overlap between native and introduced species for at least one their life stages. The endemic species that showed the highest spatial overlap with the introduced species was Ataeniobius toweri, whereas Oreochromis sp. was the introduced one with the highest overlap with the native species. All of the endemic species are endangered; was thus, the possible affectation caused by the spatial overlap between endemic and introduced species has a special interest.El humedal de la Media Luna es el más representativo y el más presionado por uso turístico y acciones de manejo en la Llanura de Rioverde, S.L.P. Contiene 13 especies de peces, dos nocturnas y 11 diurnas. Estas últimas fueron consideradas en este estudio, entre las que destacan cinco especies endémicas de la zona, una especie nativa de amplia distribución y cinco introducidas. Con la finalidad de determinar el grado de traslape espacial entre las especies, se tomaron los datos de cinco momentos de muestreo efectuados entre 1998 y 1999, con n = 54 transectos subacuáticos en cada muestreo. Se analizó tanto la distribución poblacional de los peces por clase de edad (adultos, juveniles y crías), como la similitud entre pares de especies para las variables del hábitat: sector, profundidad y vegetación. Los peces adultos y juveniles tendieron a traslaparse; las crías se segregaron en sector y se traslaparon en profundidad y vegetación. Hubo traslape considerable entre especies nativas e introducidas en al menos un estadio de vida; la especie endémica con mayor grado de superposición espacial con los introducidos fue Ataeniobius toweri, mientras que la especie introducida que mayor traslape con las nativas fue Oreochromis sp. Todas las especies endemícos se encontraron en riesgo de extinción, por lo que se considera de especial interés la posible afectación por el traslape espacial con las especies introducidas

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    Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2013Sign.: [calderón]-3[calderón]4/8, A-Z8, 2A-2Z8 3A8, 3B6.Port. con grab. xil. de Santa Teresa de Jesús.Texto con apostillas marginales y letras capitales ornadas y escudo de la orden del Carmelo también xilográfico en folio [calderón]\b2\
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