420 research outputs found

    Actividad fungicida/fungistática in vitro del fosfito de manganeso contra hongos patógenos habitantes del suelo con soja

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    Las pudriciones de raíz y tallo (PRYT) en el cultivo de soja causadas por patógenos habitantes del suelo son enfermedades comúnmente encontradas en campos de soja y son una de las causas más importantes de pérdidas económicas. La sensibilidad micelial de Fusarium virguliforme, Fusarium tucumaniae, Sclerotinia sclerotiorum y Macrophomina phaseolina fue evaluada en medio de cultivo agar papa glucosa (25 mL) suplementado con diferentes concentraciones (µg mL-1) de fosfito de manganeso (PhiMn) diluido en agua (0; 25; 37.5; 50; 100; 200; 300; 400; 500; 800 y 1000). La sensibilidad del crecimiento micelial fue analizada usando análisis de regresión lineal logarítmico. La concentración de PhiMn necesaria para inhibir el 50% del crecimiento micelial (CI50) fue calculada. Los valores de CI50 fueron desde 105 µg mL-1 (Fusarium spp.) hasta 409 µg mL-1 (M. phaseolina). La formación de esclerocios fue completamente inhibida a 500 µg mL-1. Los resultados del presente estudio representan el primer reporte de la acción fungicida/fungistática in vitro del Phi contra los hongos agentes causales de PRYT en el cultivo de soja.Soybean root and stem rots caused by soil-borne pathogens are diseases commonly found in soybean fields, and one of the most important causes of crop losses. In the present study, the mycelial sensitivity of Fusarium virguliforme, F. tucumaniae, Sclerotinia sclerotiorum and Macrophomina phaseolina was evaluated on potato dextrose agar media (25 mL) supplemented with different concentrations of manganese phosphite (MnPhi) diluted in water (0, 25, 37.5, 50, 100, 200, 300, 400, 500, 800 and 1000 µg/mL). Mycelial growth sensitivity was analyzed using logarithmic linear regression analysis. The MnPhi concentration needed to inhibit 50% of the mycelial growth (IC50) ranged from 105 µg/mL (Fusarium spp.) to 409 µg/mL (M. phaseolina). Sclerotia were completely inhibited at 500 µg/mL. The results of our study represent the first report on the direct in vitro fungicidal/fungistatic action of MnPhi against fungi that are causal agents of soil-borne diseases.Fil: Carmona, Marcelo Anibal. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología; ArgentinaFil: Simonetti, Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos. Cátedra de Microbiología Agrícola; ArgentinaFil: Ravotti, M. E.. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología; ArgentinaFil: Scandiani, María Mercedes. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Luque, A. G.. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Formento, N. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; ArgentinaFil: Sautua, Francisco. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología; Argentin

    Identification of an hepatitis delta virus-like ribozyme at the mRNA 5′-end of the L1Tc retrotransposon from Trypanosoma cruzi

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    L1Tc is a non-LTR LINE element from Trypanosoma cruzi that encodes its transposition machinery and bears an internal promoter. Herewith, we report the identification of an in vitro active hepatitis delta virus-like ribozyme located in the first 77 nt at the 5′-end of the L1Tc mRNA (L1TcRz). The data presented show that L1TcRz has a co-transcriptional function. Using gel-purified uncleaved RNA transcripts, the data presented indicate that the kinetics of the self-cleaving, in a magnesium-dependent reaction, fits to a two-phase decay curve. The cleavage point identified by primer extension takes place at +1 position of the element. The hydroxyl nature of the 5′-end of the 3′-fragment generated by the cleavage activity of L1TcRz was confirmed. Since we have previously described that the 77-nt long fragment located at the 5′-end of L1Tc has promoter activity, the existence of a ribozyme in L1Tc makes this element to be the first described non-LTR retroelement that has an internal promoter–ribozyme dual function. The L1Tc nucleotides located downstream of the ribozyme catalytic motif appear to inhibit its activity. This inhibition may be influenced by the existence of a specific L1Tc RNA conformation that is recognized by RNase P

    Pr77 and L1TcRz: A dual system within the 5′-end of L1Tc retrotransposon, internal promoter and HDV-like ribozyme

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    The sequence corresponding to the first 77 nucleotides of the L1Tc and NARTc non-LTR retrotransposons from Trypanosoma cruzi is an internal promoter (Pr77) that generates abundant, although poorly translatable, un-spliced transcripts. It has been recently described that L1TcRz, an HDV-like ribozyme, resides within the 5′-end of the RNA from the L1Tc and NARTc retrotransposons. Remarkably, the same first 77 nucleotides of L1Tc/NARTc elements comprise both the Pr77 internal promoter and the HDV-like L1TcRz. The L1TcRz cleaves on the 5′-side of the +1 nucleotide of the L1Tc element insuring that the promoter and the ribozyme functions travel with the transposon during retrotransposition. The ribozyme activity would prevent the mobilization of upstream sequences and insure the individuality of the L1Tc/NARTc copies transcribed from associated tandems. The Pr77/L1TcRz sequence is also found in other trypanosomatid’s non-LTR retrotransposons and degenerated retroposons. The possible conservation of the ribozyme activity in a widely degenerated retrotransposon, as the Leishmania SIDERs, could indicate that the presence of this element and the catalytic activity could play some favorable genetic regulation. The functional implications of the Pr77/L1TcRz dual system in the regulation of the L1Tc/NARTc retrotransposons and in the gene expression of trypanosomatids are also discussed in this paper

    Nuevas aportaciones a la flora de Andalucía: Sierra de Gádor, Almería (Andalucía, España). Nota II

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    New floristic records in Andalusia: Sierra de Gádor, Almería (Andalucía, Spain). Note II.Palabras clave. Flora, corología, Almería, Andalucía.Key words. Flora, corology, Almería, Andalusia

    Isolation of ntrA-like mutants of Azobacter vinelandii

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    A number of of chlorate-resistant mutants of Azotobacter vinelandii affected in a general control of nitrogen metabolism were isolated. These mutants could not utilize dinitrogen, nitrate, or nitrite as a nitrogen source. The reason for this inability is that they were simultaneously deficient in nitrogenase and nitrate and nitrite reductase activities. They were complemented by a cosmid carrying a DNA fragment of A. vinelandii able to complement ntrA mutants of Escherichia coli, so they seemed to be ntrA-like mutants.Comisión Asesora Científica y Técnica 302

    Ecological Diversity within Rear-Edge: A Case Study from Mediterranean Quercus pyrenaica Willd

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    Understanding the ecology of populations located in the rear edge of their distribution is key to assessing the response of the species to changing environmental conditions. Here, we focus on rear-edge populations of Quercus pyrenaica in Sierra Nevada (southern Iberian Peninsula) to analyze their ecological and floristic diversity. We perform multivariate analyses using high-resolution environmental information and forest inventories to determine how environmental variables differ among oak populations, and to identify population groups based on environmental and floristic composition. We find that water availability is a key variable in explaining the distribution of Q. pyrenaica and the floristic diversity of their accompanying communities within its rear edge. Three cluster of oak populations were identified based on environmental variables. We found differences among these clusters regarding plant diversity, but not for forest attributes. A remarkable match between the populations clustering derived from analysis of environmental variables and the ordination of the populations according to species composition was found. The diversity of ecological behaviors for Q. pyrenaica populations in this rear edge are consistent with the high genetic diversity shown by populations of this oak in the Sierra Nevada. The identification of differences between oak populations within the rear-edge with respect to environmental variables can aid with planning the forest management and restoration actions, particularly considering the importance of some environmental factors in key ecological aspects.LIFE-ADAPTAMED: Protection of key ecosystem services by adaptive management of Climate Change endangered Mediterranean socioecosystems LIFE14 CCA/ES/000612H2020 project European Long-Term Ecosystem and socio-ecological Research Infrastructure (eLTER)European Research Council (ERC) 64703

    Hallmarks of mechanochemistry: From nanoparticles to technology

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    The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).Slovak Grant Agency VEGA 2/0009/11, 2/0043/11Slovak Agency for Science and Development APVV VV-0189-10, VV-0528-11Russian Foundation for Basic Research 10-03-00942a, 12-03-00651aMinistry of Science and Higher education in Poland CUT/c-1/DS/KWC/2008-2012, PB1T09B02330, NN209145136, NN20914893

    The Tyrosine Phosphatase hPTPRβ Controls the Early Signals and Dopaminergic Cells Viability via the P2X7 Receptor

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    ATP, one of the signaling molecules most commonly secreted in the nervous system and capable of stimulating multiple pathways, binds to the ionotropic purinergic receptors, in particular, the P2X7 receptor (P2X7R) and stimulates neuronal cell death. Given this effect of purinergic receptors on the viability of dopaminergic neurons model cells and that Ras GTPases control Erk1/2-regulated mitogen-activated cell proliferation and survival, we have investigated the role of the small GTPases of the Ras superfamily, together with their regulatory and effector molecules as the potential molecular intermediates in the P2X7R-regulated cell death of SN4741 dopaminergic neurons model cells. Here, we demonstrate that the neuronal response to purinergic stimulation involves the Calmodulin/RasGRF1 activation of the small GTPase Ras and Erk1/2. We also demonstrate that tyrosine phosphatase PTPRβ and other tyrosine phosphatases regulate the small GTPase activation pathway and neuronal viability. Our work expands the knowledge on the intracellular responses of dopaminergic cells by identifying new participating molecules and signaling pathways. In this sense, the study of the molecular circuitry of these neurons is key to understanding the functional effects of ATP, as well as considering the importance of these cells in Parkinson’s Disease.This work were supported by: A.A.S. is a recipient of a predoctoral Basque Government fellowship: PRE_2017_1_0016; M.L.M. is a recipient of a fellowship from Foundation “Jesús de Gangoiti y Barrera”: Foundation “Jesús de Gangoiti y Barrera”; J.L.Z. was supported by the Instituto de Salud Carlos III: (PI18/00207); J.L.Z. was supported by the Basque Government: (PIBA_2020_1_0048); J.L.Z. was supported by the University of Basque Country Grant: (US19/04). A.A.S. is a recipient of a predoctoral fellowship (PRE_2017_1_0016) from the Basque Government; M.L.M. is a recipient of a fellowship from Foundation “Jesús de Gangoiti y Barrera”; J.L.Z. was supported by the Instituto de Salud Carlos III (PI18/00207), Basque Government (PIBA_2020_1_0048) and University of Basque Country Grant (US19/04)

    Las razas berrendas en el área de Despeñaperros

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    Las razas Berrenda en Negro y Berrenda en Colorado son razas autóctonas, rústicas y maternales que suelen usarse para cruce industrial, se encuentran en peligro de extinción, al estar disminuyendo sus efectivos, y mezclándose, cada vez más, entre sí y con otras razas. El objetivo de este trabajo fue mostrar el estado actual y el grado de diferenciación de los bovinos Berrendo en Negro y Berrendo en Colorado localizados en el entorno de Despeñaperros en base a las características externas que presentan tanto a partir de sus caracteres zoométricos, como morfológicos y fanerópticos. Para ello se han muestreado un total de 160 reproductoras distribuidas en 13 rebaños, la mayoría de los cuales criaban conjuntamente ambas razas Berrendas. Para los cálculos se utilizó el programa estadístico Statistical 6.0 para Windows, realizándose pruebas T de diferenciación entre razas para las variables zoométricas y pruebas ML_2 para los cualitativos. Las variables zoométricas Alzada a la Cruz (ACR) y Diámetro Bicostal (LB) para la Berrenda en Negro y ACR para la Berrenda en Colorado mostraron valores inferiores a los definidos por el estándar de la raza. Para los caracteres cualitativos sección y forma del cuerno, tamaño de las orejas, longitud del cuello, inclinación de la grupa, finura de la cola y nalga, en ambas razas, existen discrepancias entre lo obtenido y lo dictaminado por el estándar de la raza. Se han encontrado diferencias significativas entre ambas razas tanto para el desarrollo del cuerno, como para el perfil cefálico, tamaño de la ubre, vientre y nalga, con un nivel de significación de p<0.05

    Documenting models and workflows: the next challenge in the field of ecological data management

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    Los modelos ecológicos se han convertido en una pieza clave de esta ciencia. La generación de conocimiento se consigue en buena medida mediante procesos analíticos más o menos complejos aplicados sobre conjuntos de datos diversos. Pero buena parte del conocimiento necesario para diseñar e implementar esos modelos no está accesible a la comunidad científica. Proponemos la creación de herramientas informáticas para documentar, almacenar y ejecutar modelos ecológicos y flujos de trabajo. Estas herramientas (repositorios de modelos) están siendo desarrolladas por otras disciplinas como la biología molecular o las ciencias de la Tierra. Presentamos un repositorio de modelos (ModeleR) desarrollado en el contexto del Observatorio de seguimiento del cambio global de Sierra Nevada (Granada-Almería). Creemos que los repositorios de modelos fomentarán la cooperación entre científicos, mejorando la creación de conocimiento relevante que podría ser transferido a los tomadores de decisiones.Ecological models have become a key part of this scientific discipline. Most of the knowledge created by ecologists is obtained by applying analytical processes to primary data. But most of the information underlying how to create models or use analytic techniques already published in the scientific literature is not readily available to scientists. We are proposing the creation of computer tools that help to document, store and execute ecological models and scientific workflows. These tools (called model repositories) are being developed by other disciplines such as molecular biology and earth science. We are presenting a model repository (called ModeleR) that has been developed in the context of the Sierra Nevada Global Change Observatory (Granada-Almería. Spain). We believe that model repositories will foster cooperation among scientists, enhancing the creation of relevant knowledge that could be transferred to environmental managers.El desarrollo de ModeleR ha sido financiado por la Consejería de Medio Ambiente y Ordenación del Territorio de la Junta de Andalucía a través de la Red de Información Ambiental (REDIAM), gracias a un convenio llamado “Diseño y creación de un repositorio de modelos para la red de información ambiental de Andalucía”. A.J. Pérez-Luque agradece al MICINN por el contrato PTA 2011-6322-I
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