367 research outputs found

    Antimicrobial activity of alcoholic extracts of medicinal plants against Phytopathogenic fungi.

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    Aims: This work aimed to evaluate the antimicrobial effects of 14 alcoholic extracts of medicinal plants on the mycelial growth of Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. passiflorae, Fusarium solani and Rhizoctonia solani. Those are fungi that cause diseases in Passiflora edulis. Study Design: With the obtained data the mycelial growth rate index (MGRI) was calculated, afterwards the analysis of variance was performed and the means were compared by the Scott-Knott test at 5% probability. Place and Duration of Study: Plant Pathology Laboratory, Embrapa Eastern Amazon, BelĂ©m, ParĂĄ, Brazil, between May 2014 and April 2015. Methodology: The extracts were prepared with 1.0 g of powdered plant material and 10 mL of commercial ethyl alcohol 92.8Âș (0.1 g mL-1) under constant agitation in an orbital shaker at 200 rpm for 20 minutes. They were then kept in the refrigerator for 24 hours at rest. The extracts were centrifuged and filtered on Millipore membranes with 0.22 ”m porosity. The tests with the phytopathogenic fungi were carried out in vitro with the alcoholic extracts at 1% concentration. The experimental design was completely randomized with 15 treatments and 5 replicates. Results: All the extracts reduced the growth of the fungi C. gloeosporioides. The extracts the Eucalyptus angulosa, Lippia alba, Zingiber officinale, Cymbopagon citratus, Azadirachta indica, Plectranthus barbathus, Hibiscus sabdariffa, Aloe vera, Pedilanthus tithymaloides, Mansoa alliacea and Chenopodium ambrosioides reduced the mycelial growth of F. oxysporum f. sp. passiflorae. Only the extract of E. angulosa presented reduction in the growth of F. solani. Meanwhile the extracts of E. angulosa, Z. officinale, L. alba, M. alliacea and P. barbathus reduced the mycelial growth of R. solani. Conclusion: All extracts presented antimicrobial potential, being that the extract of E. angulosa reduced the mycelial growth of all the evaluated fungi

    Characterization and variability of strains of Xanthomonas axonopodis pv. passiflorae from the state of ParĂĄ, Brazil.

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    Bacterial spot, caused by Xanthomonas axonopodis pv. passiflorae, is a disease that has limited the cultivation of passionfruit in various orchards in Brazil. The objective of this work is to characterize and evaluate the variability of 29 strains of X. axonopodis pv. passiflorae from different municipalities producing yellow passionfruit in the state of ParĂĄ. The characterization was performed by the biochemical methods of KOH solubility, oxidase and Bactray, and the molecular methods of Xapas-F, Xapas-Ri and Xapas-Ro primers. The variability was evaluated by pathogenicity test and RAPD (randomly amplified polymorphic DNA). The strains of X. axonopodis pv. passiflorae were Gram-negative and oxidase-negative, and tests with the Bactray kit showed no relation between the collection municipality and group composition. The Xapas-F/Ri/Ro primers were specific for the strains. The primers used amplified 118 polymorphic bands in the RAPD reactions and the highest genetic similarity was between the strains PA15 and PA16. As the pathogenicity test evidenced a pathogenic variability, the strains PA2.1, PA4.5, PA14, PA4.2, PA4.1, PA4.6, PA3.4 and PA4.3 present the highest severity values for the disease. The strains of X. axonopodis pv. passiflorae show characteristics typical of the species, and genetic and pathogenic variability among them

    A Complete Classification of Higher Derivative Gravity in 3D and Criticality in 4D

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    We study the condition that the theory is unitary and stable in three-dimensional gravity with most general quadratic curvature, Lorentz-Chern-Simons and cosmological terms. We provide the complete classification of the unitary theories around flat Minkowski and (anti-)de Sitter spacetimes. The analysis is performed by examining the quadratic fluctuations around these classical vacua. We also discuss how to understand critical condition for four-dimensional theories at the Lagrangian level.Comment: 20 pages, v2: minor corrections, refs. added, v3: logic modified, v4: typos correcte

    Massive Gravity Theories and limits of Ghost-free Bigravity models

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    We construct a class of theories which extend New Massive Gravity to higher orders in curvature in any dimension. The lagrangians arise as limits of a new class of bimetric theories of Lovelock gravity, which are unitary theories free from the Boulware-Deser ghost. These Lovelock bigravity models represent the most general non-chiral ghost-free theories of an interacting massless and massive spin-two field in any dimension. The scaling limit is taken in such a way that unitarity is explicitly broken, but the Boulware-Deser ghost remains absent. This automatically implies the existence of a holographic cc-theorem for these theories. We also show that the Born-Infeld extension of New Massive Gravity falls into our class of models demonstrating that this theory is also free of the Boulware-Deser ghost. These results extend existing connections between New Massive Gravity, bigravity theories, Galileon theories and holographic cc-theorems.Comment: 11+5 page

    T-cell subpopulations αÎČ and γΎ in cord blood of very preterm infants : The influence of intrauterine infection

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    Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPreterm infants are very susceptible to infections. Immune response mechanisms in this group of patients and factors that influence cord blood mononuclear cell populations remain poorly understood and are considered insufficient. However, competent immune functions of the cord blood mononuclear cells are also described. The aim of this work was to evaluate the T-cell population (CD3+) with its subpopulations bearing T-cell receptor (TCR) αÎČ or TCR γΎ in the cord blood of preterm infants born before 32 weeks of gestation by mothers with or without an intrauterine infection. Being a pilot study, it also aimed at feasibility check and assessment of an expected effect size. The cord blood samples of 46 infants age were subjected to direct immunofluorescent staining with monoclonal antibodies and then analyzed by flow cytometry. The percentage of CD3+ cells in neonates born by mothers with diagnosis of intrauterine infection was significantly lower than in neonates born by mothers without infection (p = 0.005; Mann-Whitney U test). The number of cells did not differ between groups. Infection present in the mother did not have an influence on the TCR αÎČ or TCR γΎ subpopulations. Our study contributes to a better understanding of preterm infants' immune mechanisms, and sets the stage for further investigations.Peer reviewedFinal Published versio

    APP educativa : financiamiento y dise?o de un colegio municipal de alta calidad

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    La realidad educativa peruana atraviesa por una crisis estructural. La falta de inversi?n p?blica en infraestructura educativa y la baja calidad de la ense?anza que se brinda en los colegios estatales son algunos de los factores causantes de esta situaci?n. El examen PISA 2013, que compara el nivel educativo de los estudiantes de diversos pa?ses, mostr? que el Per? estaba en el ?ltimo lugar de Am?rica Latina en los tres rubros de la prueba: matem?tica, ciencia y comprensi?n lectora. Asimismo, la inversi?n peruana en educaci?n es una de las m?s bajas en la regi?n. Seg?n datos del Banco Mundial, en el 2006 M?xico y Cuba invirtieron el 9.11% y el 5.05% de su PBI, respectivamente, mientras que el Per? destin? solo el 2.52% del PBI para este fin. Ante esta realidad, en el 2014 el Gobierno anunci? un incremento de 0.4% del PBI, m?s de mil millones de soles, para mejorar la remuneraci?n de los docentes y la creaci?n del Programa Nacional de Infraestructura Educativa, con S/. 2,500 millones de soles durante el 2015. Al respecto, la investigaci?n contenida en este libro plantea un procedimiento para viabilizar la creaci?n de una instituci?n educativa b?sica regular que brinde servicios educativos de alto nivel, a trav?s de una APP, a un precio accesible para la poblaci?n. Al lograr que el proyecto educativo sea atractivo para los inversionistas privados, se contribuir? a cubrir la demanda de colegios y a superar el desbalance que existe en los colegios privados entre, por un lado, los precios de la matr?cula y las pensiones y, por otro, la prestaci?n de servicios educativos. La investigaci?n, centrada en el desarrollo de un proyecto de estas caracter?sticas en un distrito lime?o, permitir? evaluar la factibilidad t?cnica, econ?mica y legal de la creaci?n de un colegio v?a una APP municipal, para demostrar la viabilidad y las potencialidades de esta iniciativa

    Quadratic Curvature Gravity with Second Order Trace and Massive Gravity Models in Three Dimensions

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    The quadratic curvature lagrangians having metric field equations with second order trace are constructed relative to an orthonormal coframe. In n>4n>4 dimensions, pure quadratic curvature lagrangian having second order trace constructed contains three free parameters in the most general case. The fourth order field equations of some of these models, in arbitrary dimensions, are cast in a particular form using the Schouten tensor. As a consequence, the field equations for the New massive gravity theory are related to those of the Topologically massive gravity. In particular, the conditions under which the latter is "square root" of the former are presented.Comment: 24 pages, to appear in GR

    Emergence of Anti-Cancer Drug Resistance: Exploring the Importance of the Microenvironmental Niche via a Spatial Model

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    Practically, all chemotherapeutic agents lead to drug resistance. Clinically, it is a challenge to determine whether resistance arises prior to, or as a result of, cancer therapy. Further, a number of different intracellular and microenvironmental factors have been correlated with the emergence of drug resistance. With the goal of better understanding drug resistance and its connection with the tumor microenvironment, we have developed a hybrid discrete-continuous mathematical model. In this model, cancer cells described through a particle-spring approach respond to dynamically changing oxygen and DNA damaging drug concentrations described through partial differential equations. We thoroughly explored the behavior of our self-calibrated model under the following common conditions: a fixed layout of the vasculature, an identical initial configuration of cancer cells, the same mechanism of drug action, and one mechanism of cellular response to the drug. We considered one set of simulations in which drug resistance existed prior to the start of treatment, and another set in which drug resistance is acquired in response to treatment. This allows us to compare how both kinds of resistance influence the spatial and temporal dynamics of the developing tumor, and its clonal diversity. We show that both pre-existing and acquired resistance can give rise to three biologically distinct parameter regimes: successful tumor eradication, reduced effectiveness of drug during the course of treatment (resistance), and complete treatment failure
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