584 research outputs found

    Construção da primeira micoteca de Mycosphaerella Musicola Leach do Estado da Bahia.

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    O fungo Mycosphaerella musicola Leach é o agente causal da Sigatoka-amarela em bananeira. Essa doença é reduz da área foliar verde da planta, refletindo em menor produtividade. O objetivo do trabalho foi iniciar uma coleção de isolados de M. musicola coletados no Estado da Bahia. As amostras foram coletadas nas principais microrregiões produtoras de banana, a saber: Bom Jesus da Lapa ( Bom Jesus da Lapa), Ilhéus-Itabuna ( Presidente Tancredo Neves, Wenceslau Guimarães, Barro Preto, Gandu e Teolândia), Valença ( Morro de São Paulo) e Vitória da Conquista (Morro de São Paulo). A partir de 141 amostras coletadas consegui-se isolar e preservar 56 isolados (39,72%) em duplicata nos métodos de Castellani, BDA, BDA+Glicerol, Tiras de papel e Esferas de vidro. A primeira micoteca de Mycosphaerella musicola Leach do Estado da Bahia está sendo construída

    Variabilidade genética de isolados do fungo causador da Sigatoka- Amarela em bananeira no Estado da Bahia com o uso de SSR.

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    A bananeira assume importância econômica e social em todo o mundo, cultivada em mais de 130 países tropicais e subtropicais, principalmente por pequenos agricultores. O Brasil, em 2010 produziu 6,9 milhões de toneladas em uma área de 487 mil ha (FAO, 2012). Esta cultura apresenta importância na geração de empregos, sendo responsável pela renda de milhões de famílias. Embora este cenário seja bastante promissor, a maioria das variedades de bananeira disponível é suscetível à Sigatoka-amarela, causada pelo fungo Mycosphaerella musicola Leach, onde a aplicação sistemática de fungicidas ainda é a principal meio de controle.1 CD-ROM

    What shapes the phylogenetic structure of anuran communities in a seasonal environment? The influence of determinism at regional scale to stochasticity or antagonistic forces at local scale.

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    Ecological communities are structured by both deterministic and stochastic processes. We investigated phylogenetic patterns at regional and local scales to understand the influences of seasonal processes in shaping the structure of anuran communities in the southern Pantanal wetland, Brazil. We assessed the phylogenetic structure at different scales, using the Net Relatedness Index (NRI), the Nearest Taxon Index (NTI), and hylobetadiversity indexes, as well as a permutation test, to evaluate the effect of seasonality. The anuran community was represented by a non-random set of species with a high degree of phylogenetic relatedness at the regional scale. However, at the local scale the phylogenetic structure of the community was weakly related with the seasonality of the system, indicating that oriented stochastic processes (e.g. colonization, extinction and ecological drift) and/or antagonist forces drive the structure of such communities in the southern Pantanal

    Pharmacological Modulation of Three Modalities of CA1 Hippocampal Long-Term Potentiation in the Ts65Dn Mouse Model of Down Syndrome

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    The Ts65Dn mouse is the most studied animal model of Down syndrome. Past research has shown a significant reduction in CA1 hippocampal long-term potentiation (LTP) induced by theta-burst stimulation (TBS), but not in LTP induced by high-frequency stimulation (HFS), in slices from Ts65Dn mice compared with euploid mouse-derived slices. Additionally, therapeutically relevant doses of the drug memantine were shown to rescue learning and memory deficits in Ts65Dn mice. Here, we observed that 1 mu M memantine had no detectable effect on HFS-induced LTP in either Ts65Dn- or control-derived slices, but it rescued TBS-induced LTP in Ts65Dn-derived slices to control euploid levels. Then, we assessed LTP induced by four HFS (4xHFS) and found that this form of LTP was significantly depressed in Ts65Dn slices when compared with LTP in euploid control slices. Memantine, however, did not rescue this phenotype. Because 4xHFS-induced LTP had not yet been characterized in Ts65Dn mice, we also investigated the effects of picrotoxin, amyloid beta oligomers, and soluble recombinant human prion protein (rPrP) on this form of LTP. Whereas >= 10 mu M picrotoxin increased LTP to control levels, it also caused seizure-like oscillations. Neither amyloid beta oligomers nor rPrP had any effect on 4xHFS-induced LTP in Ts65Dn-derived slices.Alana USA Foundation [124124]Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Awakening AngelsNIH [NS083687]Case Western Reserve Univ, Dept Pediat, Div Pediat Neurol, Cleveland, OH 44106 USAUniv Fed Sao Paulo, Cardiol, Postgrad Program Med, BR-04024002 Sao Paulo, SP, BrazilCase Western Reserve Univ, Dept Physiol & Biophys, Cleveland, OH 44106 USACase Western Reserve Univ, Dept Psychiat, Cleveland, OH 44106 USAUniv Fed Sao Paulo, Cardiol, Postgrad Program Med, BR-04024002 Sao Paulo, SP, BrazilCAPES: NS083687Web of Scienc

    The Hubble constant and dark energy from cosmological distance measures

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    We study how the determination of the Hubble constant from cosmological distance measures is affected by models of dark energy and vice versa. For this purpose, constraints on the Hubble constant and dark energy are investigated using the cosmological observations of cosmic microwave background, baryon acoustic oscillations and type Ia suprenovae. When one investigates dark energy, the Hubble constant is often a nuisance parameter, thus it is usually marginalized over. On the other hand, when one focuses on the Hubble constant, simple dark energy models such as a cosmological constant and a constant equation of state are usually assumed. Since we do not know the nature of dark energy yet, it is interesting to investigate the Hubble constant assuming some types of dark energy and see to what extent the constraint on the Hubble constant is affected by the assumption concerning dark energy. We show that the constraint on the Hubble constant is not affected much by the assumption for dark energy. We furthermore show that this holds true even if we remove the assumption that the universe is flat. We also discuss how the prior on the Hubble constant affects the constraints on dark energy and/or the curvature of the universe.Comment: 45 pages, 15 figure

    Dextran-Coated Magnetic Supports Modified with a Biomimetic Ligand for IgG Purification

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    The authors thank the financial support from Fundacao para a Ciencia e a Tecnologia through Grant PEst-C/EQB/LA0006/2011 and contracts no. PTDC/EBB-BIO/102163/2008, PTDC/EBB-BIO/098961/2008, PTDC/EBB-BIO/118317/2010, SFRH/BD/72650/2010 for V.L.D, and Santander Totta Bank - Universidade Nova de Lisboa for the Scientific Award 2009/2010. The authors are grateful to Dr. Abid Hussain and M. Telma Barroso (REQUIMTE, FCT-UNL, Portugal) for the preparation of the synthetic affinity ligands, to Lonza Biologics, U.K. (Dr. Richard Alldread), and the Animal Cell Technology Unit of ITQB-UNL/IBET (Dr. Paula M Alves and Dr. Ana Teixeira) for providing the cells and the culture bulks and to Mr. Filipe Cardoso and Prof. Paulo Freitas (INESC-MN, Lisbon, Portugal) for the help with the VSM measurements.Dextran-coated iron oxide magnetic particles modified with ligand 22/8, a protein A mimetic ligand, were prepared and assessed for IgG purification. Dextran was chosen as the agent to modify the surface of magnetic particles by presenting a negligible level of nonspecific adsorption. For the functionalization of the particles with the affinity ligand toward antibodies, three methods have been explored. The optimum coupling method yielded a theoretical maximum capacity for human IgG calculated as 568 ± 33 mg/g and a binding affinity constant of 7.7 × 10⁴ M⁻¹. Regeneration, recycle and reuse of particles was also highly successful for five cycles with minor loss of capacity. Moreover, this support presented specificity and effectiveness for IgG adsorption and elution at pH 11 directly from crude extracts with a final purity of 95% in the eluted fraction.proofpublishe

    Essential Constants for Spatially Homogeneous Ricci-flat manifolds of dimension 4+1

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    The present work considers (4+1)-dimensional spatially homogeneous vacuum cosmological models. Exact solutions -- some already existing in the literature, and others believed to be new -- are exhibited. Some of them are the most general for the corresponding Lie group with which each homogeneous slice is endowed, and some others are quite general. The characterization ``general'' is given based on the counting of the essential constants, the line-element of each model must contain; indeed, this is the basic contribution of the work. We give two different ways of calculating the number of essential constants for the simply transitive spatially homogeneous (4+1)-dimensional models. The first uses the initial value theorem; the second uses, through Peano's theorem, the so-called time-dependent automorphism inducing diffeomorphismsComment: 26 Pages, 2 Tables, latex2

    Comparison of Standard Ruler and Standard Candle constraints on Dark Energy Models

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    We compare the dark energy model constraints obtained by using recent standard ruler data (Baryon Acoustic Oscillations (BAO) at z=0.2 and z=0.35 and Cosmic Microwave Background (CMB) shift parameters R and l_a) with the corresponding constraints obtained by using recent Type Ia Supernovae (SnIa) standard candle data (ESSENCE+SNLS+HST from Davis et. al.). We find that, even though both classes of data are consistent with LCDM at the 2\sigma level, there is a systematic difference between the two classes of data. In particular, we find that for practically all values of the parameters (\Omega_0m,\Omega_b) in the 2\sigma range of the the 3-year WMAP data (WMAP3) best fit, LCDM is significantly more consistent with the SnIa data than with the CMB+BAO data. For example for (\Omega_0m,\Omega_b)=(0.24,0.042) corresponding to the best fit values of WMAP3, the dark energy equation of state parametrization w(z)=w_0 + w_1 (z/(1+z)) best fit is at a 0.5\sigma distance from LCDM (w_0=-1,w_1=0) using the SnIa data and 1.7\sigma away from LCDM using the CMB+BAO data. There is a similar trend in the earlier data (SNLS vs CMB+BAO at z=0.35). This trend is such that the standard ruler CMB+BAO data show a mild preference for crossing of the phantom divide line w=-1, while the recent SnIa data favor LCDM. Despite of this mild difference in trends, we find no statistically significant evidence for violation of the cosmic distance duality relation \eta \equiv d_L(z)/(d_A(z) (1+z)^2)=1. For example, using a prior of \Omega_0m=0.24, we find \eta=0.95 \pm 0.025 in the redshift range 0<z<2, which is consistent with distance duality at the 2\sigma level.Comment: References added. 9 pages, 7 figures. The Mathematica files with the numerical analysis of the paper can be found at http://leandros.physics.uoi.gr/rulcand/rulcand.ht

    Geochemical and environmental assessment of potential effects of trace elements in soils, water, and sediments around abandoned mining sites in the northern Iberian Peninsula (NW Spain)

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    The mineral deposits and traces in the Iberian Peninsula are very numerous and of varied mineralogy. This study aimed to analyze the geochemical and environmental changes detected in soil, water, and sediments around the La Sierre mine, and to determine if contamination persists over time. The concentrations of ten trace elements (As, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, Zn) were measured in 20 soil samples, 10 water samples, and 6 sediment samples, sampling at the most affected points. Soil and sediment samples were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and water samples by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). From the Principal Component Analysis (PCA), soil samples SOI-6, 7, and 20 presented high amounts ranging from 14489.86a ±7 to 3031.72b ± 1 mg/kg of Co, Cu, Ni, and As, respectively. Water samples WAT-6, 8, and 10 presented high contents of As, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn, being sample WAT-8 with high values of As, Co, Cu, Fe, and Ni with 48.1 ± 0.82, 368 ± 4, 68.3 ± 0.1, 97.5 ± 1.2, and 152 ± 2 μg/L, respectively, exceeding the regulation given by R.D 314/2016 (Water for human consumption). The sediment samples were compared with the IInterim Sediment Quality Guideline (ISQG) and Probable Effect Level (PEL) values given by the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life. When presenting a high ISQG value, but low PEL, they partially comply with the regulations, which happens with samples SED-1, 2, and 8 for As and SED-5, 6, and 7 for Pb. On the contrary, Cr and Cu do not comply with what is established in samples SED-8 and SED-1 and 8, respectively, whereas, in samples SED-2 and 5, Cu partially complies with the established regulations. The values found for the trace elements present in the abandoned traditional mining area with abundant epithermal deposits prevail over time in soil, water, and sediments

    Resposta da alface em sistema agroflorestal irrigado por gotejamento.

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    Resumo: Os sistemas agroflorestais (SAFs) proporcionam comumente uma otimização da área de cultivo, mão-de-obra, insumos e água, com maior estabilidade e diversificação da produção, maior eficiência no controle de plantas espontâneas e proteção do solo contra a erosão. Contudo, atualmente são escassos os estudos sobre SAFs irrigados. Desta forma, este trabalho teve como objetivo avaliar a produção da cultura da alface (Lactuca sativa L.) em cultivo solteiro e consorciado com rúcula (Eruca sativa L.) e rabanete (Raphanus sativus L.), no interior de um SAF e a pleno sol, sob irrigação por gotejamento. O estudo foi conduzido no Sítio Agroecológico da Embrapa Meio Ambiente, em Jaguariúna, SP. Os resultados demonstraram que o sistema de condução não influenciou o diâmetro horizontal da alface, enquanto o cultivo a pleno sol promoveu maior produção de massa seca e número de folhas de alface e rúcula. O rabanete apresentou folhas mais longas no SAF quando comparado ao pleno sol. O policultivo aumentou a produção por unidade de área, em 129,5% em média, em relação ao monocultivo no SAF e pleno sol. Estes resultados demonstraram que a consorciação foi vantajosa em relação ao monocultivo, ao produzir uma maior quantidade de hortaliças por unidade de área e insumos
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