1,702 research outputs found

    Genetic variability within accessions of the B73 maize inbred line

    Get PDF
    The maize inbred line B73 has been extensively studied at the molecular level. Researchers now have access to the genome sequence of B73 as well as to databases of biallelic and multiallelic markers where functional poly- morphisms between B73 and a public inbred line population can be compared to relate genotypes to phenotypes. This indicates the importance to determine the genetic fidelity of the germplasm during preservation and propa- gation processes, in particular, when seeds of reference inbred lines such as B73 are maintained. The aim of this study was to assess the genetic uniformity among three different sources of the B73 inbred line by means of 75 Simple Sequence Repeats (SSRs). The three B73 sources showed homozygosis; however, some accessions dif- fered greatly from the expected locus size predicted at the reference B73 genomic sequence. A particular haplo- type was prevalent in the USDA accession PI550473. The error rate of the allele size determination was estimated. The genotyping technique used in this work allowed the separation of alleles of ± 2 bp range difference within the same electrophoresis run, whereas allele size estimations between experiments, within the laboratory, differed in ± 4 bp range difference. Besides experimental errors in genotyping, the putative cause of differences among ac- cessions could be attributed to seed contamination and genetic drift. The B73 accessions evaluated in our work can be shared among laboratories to precise genotyping and phenotyping of maize inbred lines

    Stability of relative equilibria with singular momentum values in simple mechanical systems

    Full text link
    A method for testing GμG_\mu-stability of relative equilibria in Hamiltonian systems of the form "kinetic + potential energy" is presented. This method extends the Reduced Energy-Momentum Method of Simo et al. to the case of non-free group actions and singular momentum values. A normal form for the symplectic matrix at a relative equilibrium is also obtained.Comment: Partially rewritten. Some mistakes fixed. Exposition improve

    Maize Nitrogen Use Efficiency: QTL Mapping in a U.S. Dent x Argentine-Caribbean Flint RILs population

    Get PDF
    This study was aimed to identify quantitative trait loci (QTL) for nitrogen use efficiency(NUE) and related traits in a maize population derived from a cross between two lines with different genetic background (B100 and LP2). Recombinant inbred lines (181) from this population were evaluated under fieldconditions during two growing seasons, and significant(P < 0.01) phenotypic and genotypic variability was detected for most evaluated traits. Two different mapping methods were applied for detecting QTLs. Firstly, a trait by trait approach was performed on across environments, and 19 QTLs were identified.Secondly, a multi-trait multi-environment analysis detected seven joint QTLs. Almost all joint QTLs had inconsistent additive effects from one environment to another, which would reflectpresence of QTL × Environment interaction. Most joint QTLs co-localized with QTLs detected by indi-vidual mapping. We detected consistent additive effects for grain yield per plant and NUE, as well as for biomass and nitrogen harvest index in some joint QTLs, especially QTL-1 and QTL-6. These QTLs had positive and stable effects across environments, and presence of some genes within these QTL intervals could be relevant for selecting for both NUE and grain yield simultaneously. Up today, this is a firstreport on the co-localization of QTLs for enhan-ced allocation of biomass allocation to grains with NUE, and NUE candidate gene identificaion. Fine mapping of these regions could allow to detect additional markers more closely linked to these QTLs that could be used for marker assisted selection for NUE

    Pautas para el Programa de Resocialización en la Cárcel Pública de Santiago de Veraguas

    Get PDF
    Marco experencial. El por qué de las cárceles. Criminalidad y/o delincuencia en la provincia. Significado e importancia de la resocialización. Objetivos generales. Objetivos específicos. Beneficios. Área de ejecución. Recursos. Diagnóstico. Personal. Aspecto laboral. Aspecto educativo. Servicios comunitarios. Visitas conyugales. Actividades deportivas. Obstáculos y deficiencias. Resultados. Proyecto de intervención. Pautas para el programa. Cronograma. Fundamento Legal. Bibliografí

    Instrumental texture analysis on the surface of dry-cured ham to define the end of the process

    Get PDF
    The end of the elaboration process of dry-cured ham is currently decided by product weight loss and/or by an expert who carries out an evaluation of the tactile texture on the surface. The objective of this study was to define the optimal measurement conditions of an instrumental texture analysis on the surface of the dry-cured ham (ITAS), to define the end of process. 120 dry-cured hams were classified by experts into Hard (appropriate) or Soft (non-appropriate) texture groups and used to perform compression tests using different probes on three anatomical positions. Results showed that the small probe in position 2 gave the most discriminant conditions, providing representative information of the internal texture. Although classification using only weight loss was possible with an accuracy rate of 80.4 % or 66.7% depending on the weight loss, the maximum classification accuracy was obtained when using ITAS in combination with weight loss. Further studies at industrial level are needed.info:eu-repo/semantics/acceptedVersio

    Aves y peces como bioindicadores de las alteraciones debidas al turismo en manantiales de zonas semiáridas en México: bases para la gestión

    Get PDF
    Tourist disturbance in semi–arid springs was analysed; birds and fish were selected as bioindicators. Media Luna spring is the biggest and most spatially complex system in the region, with the highest biodiversity levels and tourist use. Areas with the highest bird species richness and abundances showed highest structural heterogeneity and least direct human impact. No differences in species richness of fish were observed between sectors and the most abundant species were found in the sectors least perturbed by human activity. Factors that explained the bird distribution were the species´ tolerance to the effects of direct tourism (noise and direct presence of people) and habitat quality, mainly riparian vegetation. Aquatic vegetation condition was very important for fish. Six bird species and two fish species were relevant as indicators of the habitat quality related to human impact. Anthropic disturbance such as tree plantation favoured some bird species, whereas aquatic vegetation removal was favourable for some fish species, such as the endemic Cichlasoma bartoni, however, both types of disturbance were unfavourable for other species; riparian vegetation removal was negative for both groups. Controlled tourism promotes good conditions for C. bartoni establishment. Efficient conservation measures such as limiting touristic distribution are necessary for all species, especially for the fish community, in order to conserve biodiversity in general. Key words: Wetlands, Species distribution, Threatened species, Endemism, Habitat loss, Spatial heterogeneity, Bioindicators.Para analizar las alteraciones por el turismo en manantiales de zonas semiáridas se utilizaron aves y peces como bioindicadores. Se seleccionó el manantial de la Media Luna por ser el más grande y complejo, y por incluir la más alta biodiversidad y el mayor impacto turístico en la zona. Los sectores con alta diversidad y abundancias de aves fueron los que tienen la mayor heterogeneidad estructural y menor impacto humano directo. Las mayores abundancias de peces se encontraron en los sectores menos perturbados sin diferencias para la riqueza de especies. Los factores que explicaron la distribución de las aves fueron la tolerancia de las especies a los efectos directos del turismo (ruido y presencia directa de gente) y la calidad del hábitat, principalmente la vegetación ribereña. La condición de la vegetación acuática fue muy importante para los peces. Seis especies de aves y dos de peces fueron relevantes como indicadores de la calidad del hábitat en función del impacto humano. Las alteraciones antrópicas tales como la plantación de árboles favoreció a algunas especies de aves mientras que la eliminación de la vegetación acuática fue favorable para algunos peces como el endémico Cichlasoma bartoni, pero estas alteraciones fueron negativas para otras especies; la eliminación de la vegetación ribereña tuvo efectos negativos para ambos grupos. El turismo controlado crea condiciones favorables para C. bartoni. Para la conservación de la biodiversidad en general, se requieren medidas eficientes de conservación tales como la restricción geográfica del turismo especialmente importante para la comunidad de peces. Palabras clave: Humedales, Distribución de las especies, Especies amenazadas, Endemismos, Pérdida de hábitat, Heterogeneidad espacial, Bioindicadores
    corecore