2,868 research outputs found

    Mieropaleontologieal study of an holoeene eoastal peat in the Ría de Ares (A Coruña, España)

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    [Resumen] El análisis de polen, diatomeas y foraminíferos de un sedimento litoral en la Ría de Ares (A Coruña, España) ha permitido interpretaciones paleoambientales comparables. Se trata de un sedimento turboso con macrorrestos vegetales. El análisis micropaleontológico de este nivel y las dataciones absolutas sitúan la formación del mismo en el período Subboreal. La lectura paleoecológica obtenida a través del estudio micropaleontológico nos permite reconstituir dos paleoambientes fundamentalmente: un medio continental vegetado y un ambiente con condiciones salobres, consecuencia del aumento del nivel del mar.[Abstract] Pollen, diatoms and foraminifera from a raised marine sediment of the Ría de Ares (A Coruña, Spain) area produced comparable paleoenvironntental interpretations. It is an organic formation with peat associated with numerous vegetal rests. The micropaleontological analysis of this level and the absolute dating, place its formation in the Subboreal periodo The paleoecological reading obtained from a micropaleontological study allows us to reconstitute two basic paleoenvironments: a vegetal continental environment and an environment with salty conditions, as a consequence of the sea level increas

    Structure factor and dynamics of the helix-coil transition

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    Thermodynamical properties of the helix-coil transition were successfully described in the past by the model of Lifson, Poland and Sheraga. Here we compute the corresponding structure factor and show that it possesses a universal scaling behavior near the transition point, even when the transition is of first order. Moreover, we introduce a dynamical version of this model, that we solve numerically. A Langevin equation is also proposed to describe the dynamics of the density of hydrogen bonds. Analytical solution of this equation shows dynamical scaling near the critical temperature and predicts a gelation phenomenon above the critical temperature. In the case when comparison of the two dynamical approaches is possible, the predictions of our phenomenological theory agree with the results of the Monte Carlo simulations.Comment: 11 pages, 7 figure

    A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis

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    Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far

    Genetic variability of half-sib progenies of coriander

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    Grande número de produtores envolve-se com o cultivo do coentro durante todo o ano, tornando a cultura importante social e economicamente. Praticamente em toda a região Nordeste utiliza-se a cultivar Verdão. Estudos da variabilidade genética do coentro são importantes, tendo em vista o melhor planejamento de programas de melhoramento genético. Desta forma, este trabalho teve como objetivo quantificar a variabilidade genética de características agronômicas do coentro cultivar Verdão, avaliando-se progênies de meios-irmãos potencialmente úteis no melhoramento genético. O trabalho foi desenvolvido na Universidade Federal Rural de Pernambuco, em casa de vegetação, em blocos casualizados, com cinco repetições e parcelas de 28 plantas, colocadas em dois vasos. Os tratamentos foram compostos por 55 progênies de meios-irmãos da cultivar Verdão. O teste t detectou significância a 1 e a 5% de probabilidade entre as correlações genotípicas, fenotípicas e ambientais. A herdabilidade no sentido amplo variou de 7,19 (peso médio de plantas) a 81,09 (número de plantas pendoadas). Para a razão entre os coeficientes de variação genético e ambiental (CVg /CVe), obteve-se de 0,27 (peso médio de plantas) a 2,07 (número de plantas pendoadas), indicando que a seleção contra o pendoamento apresenta as condições mais favoráveis em termos de ganhos genéticos imediatos. A correlação genotípica entre altura de plantas não pendoadas e número de plantas pendoadas foi alta e significativa.A large number of producers are involved in the cultivation of coriander throughout the year in Brazil, making it a crop of social and economic importance. Throughout nearly the entire Northeast Region, cultivar Verdão is used. Genetic variability studies on coriander are important for the proper planning of genetic improvement programs. The aim of the present study was to quantify the genetic variability for agronomic characteristics in cv. Verdão to contribute information toward genetic improvement. The study was developed at Universidade Federal Rural de Pernambuco, Pernambuco State, Brazil, in a greenhouse, using randomized blocks of 28 plants in two pots and five replications. The treatments were composed of 55 half-sib progenies from cultivar Verdão. The t test detected significance at 1 and 5% likelihood between the genotypic, phenotypic and environmental correlations. Broad sense heritability ranged from 7.19 for average plant weight to 81.09 for number of bolted plants. The ratio between genetic and environmental coefficients of variation (CVg/CVe) ranged from 0.27 (average weight) to 2.07 (number of bolted plants), indicating that selection against bolting presents more favorable conditions in terms of immediate genetic gains. The genotype correlation between height of non-bolted plants and the number of bolted plants was considered strong (0.86) and highly significant (t test), enabling simultaneous gains from selection

    Infraspecific variability in the essential oil composition of Lychnophora ericoides

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    Variations in the composition of the leaf essential oils of wild Lychnophora ericoides, with and without scent, which were grown in three sampling sites, were examined by GC-MS. Results were submitted to principal component and cluster analysis which allowed for two groups of essential oils to be distinguished with regard to scent: cluster I with specimens exhibiting an aromatic scent and containing a high percentage of α-bisabolol (34 ± 23%) and o-cymene (8.4 ± 6.9%); cluster II with specimens without any scent and characterised by a high percentage of caryophyllene oxide (11 ± 9%) and δ-elemene (5.7 ± 6.9%). The two types of oil coexist in all the populations under study, although patterns of aromatic samples deriving from Caldas Novas' State Park reveal chemical differences in relation to the samples from Brasília's National Park and Santo Antônio do Descoberto. Such chemical variations clearly suggest, apart from a geographical influence, genetic differences between individuals in the populations. The high content of α-bisabolol supports the folk medicinal use of arnica as anti-inflammatory

    Astrophysics at n-TOF facility

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    Heavy elements with Z ≥ 30 are made by neutron capture reactions during stellar He burning and presumably in supernovae. This contribution deals mainly with the slow neutron capture (s) process which is responsible for about one half of the abundances in the mass region between Fe and Bi. The slow time scale implies that the reaction path of this process involves mostly stable isotopes which can be studied in detail in laboratory experiments. The neutron time of flight (n_TOF) facility at CERN is a neutron spallation source, its white neutron energy spectrum ranges from thermal to several MeV, covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross section required in s-process nucleosynthesis. This contribution gives an overview on the astrophysical program made at n_TOF facility, the results and the implications will be considered.European Commission (EC) FIKW-CT-2000-0010

    Morphological characterization of coriander genotypes

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    Poucas cultivares de coentro (Coriandrum sativum L.) estão disponíveis aos produtores e, em algumas regiões, cultivam-se genótipos de origem desconhecida, mantidos pelos próprios hortelãos. Para conservar as cultivares tradicionais é necessário não só coletá-las e conservá-las, mas também caracterizá-las. Dessa forma, este trabalho teve por objetivo determinar caracteres morfológicos para diferenciar genótipos de coentro no processo de registro de cultivares. Foram realizados dois experimentos, ambos em blocos casualizados, com cinco repetições. As cultivares Americano, Asteca, Palmeira, Português, Santo, Supéria, Tabocas, Tapacurá e Verdão, além da linhagem HTV-9299 foram analisadas para caracteres de fruto, plântula, folhas, folíolos e flores. Os dados obtidos foram submetidos à análise de variância univariada. A cultivar Palmeira apresentou frutos de maior tamanho e massa. Já para antocianina a cultivar Americano apresentou menor intensidade, ou praticamente ausência do pigmento tanto nas plântulas quanto nas plantas, ao contrário da cultivar Tabocas que apresentou maior intensidade. As cultivares Americano, Tabocas, Palmeira, Asteca, Verdão e Tabocas e a linhagem HTV-9299 possuem maior número de folhas basais, no entanto, as cultivares que produziram maior quantidade de massa por planta foram Tabocas, Palmeira, Verdão, HTV-9299 e Tapacurá. A cultivar Americano possui folíolo verde claro pouco amarelado, a linhagem HTV-9299 folíolo verde e a cultivar Tabocas folíolo verde escuro. Os descritores morfológicos com maior poder discriminatório para o grupo de dez cultivares avaliadas foram tamanho e massa de fruto; antocianina na plântula e planta; número de folhas basais; comprimento da quinta folha; tamanho e coloração de folíolo; número de dias para pendoamento e abertura da primeira flor e massa da planta fresca.Few coriander cultivars (Coriandrum sativum L.) are available to producers and, in some regions, are grown genotypes of unknown origin, kept by the growers themselves. To conserve such traditional crops it is necessary to collect, save, and characterize them. Thus, this study was to determine morphological characters to differentiate coriander genotypes aiming the registration of cultivars. Two trials were carried out, and the experimental design used in both was in completely randomized blocks with five replications. Americano, Asteca, Palmeira, Português, Santo, Superia, Tabocas, Tapacurá, and Verdão cultivars, and the line HTV-9299 were characterized for seedling, leaflets, leaves, fruits, and flowers. The data were subjected to a univariate ANOVA. The fruits of cv. Palmeira exhibited greater size and mass. As regards the presence of anthocyanins in seedlings and plants, cv. Americano showed the lowest intensity or slight pigmentation while cv. Tabocas had the highest pigmentation. The cultivars Americano, Palmeira, Asteca, Verdão, and Tabocas and the line HTV-9299 displayed higher number of basal leaves, however, the genotypes that produced larger amount of mass per plant were Tabocas, Palmeira, Verdão, HTV-9299, and Tapacurá. The green tone of leaflets showed differences among cultivars. So, cv. Americanos leaflets exhibited a light green, slightly yellowish color, HTV-9299 green, and Tabocas dark green. The morphological traits with higher discriminatory power for the group of the ten evaluated cultivars were: size and weight of fruits; presence or absence of anthocyanin in seedlings and plants; number of basal leaves; length of the fifth leaf; size and color of leaflets; number of days to bolting initiation, and opening of the first flower, and plant fresh mass
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