2,105 research outputs found

    Growth inhibition of <i>Beauveria bassiana</i> by bacteria isolated from the cuticular surface of the corn leafhopper, <i>Dalbulus maidis</i> and the planthopper, <i>Delphacodes kuscheli</i>, two important vectors of maize pathogens

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    The phytosanitary importance of the corn leafhopper, Dalbulus maidis (Delong and Wolcott) (Hemiptera: Cicadellidae) and the planthopper, Delphacodes kuscheli (Fennah) (Hemiptera: Delphacidae) lies in their ability to transmit phloem-associated plant pathogens, mainly viruses and mollicutes, and to cause considerable mechanical damage to corn plants during feeding and oviposition. Fungi, particularly some members of the Ascomycota, are likely candidates for biocontrol agents against these insect pests, but several studies revealed their failure to invade the insect cuticle possibly because of the presence of inhibitory compounds such as phenols, quinones, and lipids and also by the antibiosis effect of the microbiota living on the cuticular surface of the host. The present work aims to understand interactions between the entomopathogenic fungus Beauveria bassiana (Balsamao-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) and bacterial antagonists isolated from the cuticular surface of D. maidis and D. kuscheli. A total of 155 bacterial isolates were recovered from the insect's cuticle and tested against B. bassiana. Ninety-one out of 155 strains inhibited the growth of B. bassiana. Bacterial strains isolated from D. maidis were significantly more antagonistic against B. bassiana than those isolates from D. kuscheli. Among the most effective antagonistic strains, six isolates of Bacillus thuringiensis Berliner (Bacillales: Bacillaeae), one isolate of B. mycoides Flügge, eight isolates of B. megaterium de Bary, five isolates of B. pumilus Meyer and Gottheil, one isolate of B. licheniformis (Weigmann) Chester, and four isolates of B. subtilis (Ehrenberg) Cohn were identified.Facultad de Ciencias Agrarias y Forestale

    Effect of a glyphosate formulation on freshwater plankton: A community combined metric approach

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    Aim: The aim of this study was to experimentally assess the effects of glyphosate formulation on plankton composition by using different community parameters through a mesocosm experiment. Methodology: A 600 l mesocosm experiment was performed for 7 days, including a control (without glyphosate) and two concentrations of glyphosate. Results: Glyphosate caused a significant decrease in cladoceran density and a significant increase in rotifer, Chlorophyceae, and Euglenophyceae densities. In addition, zooplankton size diversity as well as microalgal evenness diminished. Interpretation:The decrease in cladoceran density may have benefited rotifers since they are less competitive for food resources. Moreover, the decrease in cladoceran foraging pressure over Chlorophyceae and Euglenophyceae may have benefited them. The different tolerances and competitiveness within the plankton components make the structure of this community a good indicator of environmental disturbance.Fil: Polla, Wanda. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Laboratorio de Ecotoxicologia; ArgentinaFil: Regaldo, Luciana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Laboratorio de Ecotoxicologia; ArgentinaFil: Reno, Ulises. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Laboratorio de Ecotoxicologia; ArgentinaFil: Popielarz, Andrea Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Gervasio, Susana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Fernandez, V.. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Laboratorio de Ecotoxicologia; ArgentinaFil: Gagneten, Ana María. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Laboratorio de Ecotoxicologia; Argentin

    GATA3 protein as a MUC1 transcriptional regulator in breast cancer cells

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    INTRODUCTION: Recent studies have demonstrated that members of the GATA-binding protein (GATA) family (GATA4 and GATA5) might have pivotal roles in the transcriptional upregulation of mucin genes (MUC2, MUC3 and MUC4) in gastrointestinal epithelium. The zinc-finger GATA3 transcription factor has been reported to be involved in the growth control and differentiation of breast epithelial cells. In SAGE (serial analysis of gene expression) studies we observed an intriguing significant correlation between GATA3 and MUC1 mRNA expression in breast carcinomas. We therefore designed the present study to elucidate whether MUC1 expression is regulated by GATA3 in breast cancer cells. METHODS: Promoter sequence analysis of the MUC1 gene identified six GATA cis consensus elements in the 5' flanking region (GATA1, GATA3 and four GATA-like sequences). Chromatin immunoprecipitation and electrophoretic mobility-shift assays were employed to study the presence of a functional GATA3-binding site. GATA3 and MUC1 expression was analyzed in vitro with a GATA3 knockdown assay. Furthermore, expression of GATA3 and MUC1 genes was analyzed by real-time RT-PCR and immunohistochemistry on breast cancer-specific tissue microarrays. RESULTS: We confirmed the presence of a functional GATA3-binding site on the MUC1 promoter region in the MCF7 cell line. We determined that GATA3 knockdown assays led to a decrease in MUC1 protein expression in MCF7 and T47D cells. In addition, we detected a statistically significant correlation in expression between GATA3 and MUC1 genes at the mRNA and protein levels both in normal breast epithelium and in breast carcinomas (p = 0.01). GATA3 expression was also highly associated with estrogen receptor and progesterone receptor status (p = 0.0001) and tumor grade (p = 0.004) in breast carcinomas. CONCLUSION: Our study provides evidence indicating that GATA3 is probably a mediator for the transcriptional upregulation of MUC1 expression in some breast cancers

    New records of Ascomycota in the Northwestern Argentinean Yungas

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    We report new records for nine species of ascomycetes from the Yungas of northwestern Argentina. Capronia nigerrima, Capronia pulcherrima and Rosellinia dingleyae are new records for South America. Byssosphaeria rhodomphala, Camarops tubulina, Cercophora ambigua, Chaetosphaerella phaeostroma, Tubeufia, cylindrothecia are new species for Argentina, and Togninia minima is a new record for the biome.Fil: Gallo, María Cecilia Fátima. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucuman. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Miguel Lillo; ArgentinaFil: Robledo, Gerardo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Romero, Andrea Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Plantas Tóxicas y Medicinales, Metabolismo de Compuestos Sintéticos y Naturales - Hongos que Intervienen en la Degradación Biológica; ArgentinaFil: Catania, Myriam del V.. Fundación Miguel Lillo; Argentin

    New Insight into the FS CMa System MWC 645 from Near-Infrared and Optical Spectroscopy

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    The B[e] phenomenon is manifested by a heterogeneous group of stars surrounded by gaseous and dusty circumstellar envelopes with similar physical conditions. Among these stars, the FS CMa-type objects are suspected to be binary systems, which could be experiencing or have undergone a mass-transfer process that could explain the large amount of material surrounding them. We aim to contribute to the knowledge of a recently confirmed binary, MWC 645, which could be undergoing an active mass-transfer process. We present near-infrared and optical spectra, identify atomic and molecular spectral features, and derive different quantitative properties of line profiles. Based on publicly available photometric data, we search for periodicity in the light curve and model the spectral energy distribution. We have detected molecular bands of CO in absorption at 1.62 μ\mum and 2.3 μ\mum for the first time. We derive an upper limit for the effective temperature of the cool binary component. We found a correlation between the enhancement of the Hα\alpha emission and the decrease in optical brightness that could be associated with mass-ejection events or an increase in mass loss. We outline the global properties of the envelope, possibly responsible for brightness variations due to a variable extinction, and briefly speculate on different possible scenarios.Comment: 20 pages, 11 figures, 2 tables, published in Galaxie

    CCD BVI photometry and Coravel observations of stars in the open cluster NGC 2489

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    We present CCD BVI photometry for the southern open cluster NGC 2489 and its surrounding field. The sample consists of 2182 stars measured in an area of 13.6 × 13.6 arcmin2, extending down to V∼ 21.5. These data are supplemented with CORAVEL radial-velocity observations for seven red giant candidates. A cluster angular radius of 6.7 ± 0.6 arcmin, equivalent to 3.5 ± 0.3 pc, is estimated from star counts carried out inside and outside the cluster region. The comparison of the cluster colour-magnitude diagrams with isochrones of the Padova group yields E(B−V) = 0.30 ± 0.05, E(V−I) = 0.40 ± 0.05 and V−MV= 12.20 ± 0.25 for log t= 8.70 (t= 500+130−100 Myr) and Z= 0.019. NGC 2489 is then located at 1.8 ± 0.3 kpc from the Sun and 25 pc below the Galactic plane. The analysis of the kinematical data allowed us to confirm cluster membership for six red giants, one of them being a spectroscopic binary. A mean radial velocity of 38.13 ± 0.33 km s−1 was derived for the cluster red giants. The properties of a sample of open clusters aligned along the line of sight of NGC 2489 are examine

    The aT distribution of the Z boson at hadron colliders

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    We provide the first theoretical study of a novel variable, aTa_T, proposed in Ref.[1] as a more accurate probe of the region of low transverse momentum pTp_T, for the ZZ boson pTp_T distribution at hadron colliders. The aTa_T is the component of pTp_T transverse to a suitably defined axis. Our study involves resummation of large logarithms in aTa_T up to the next-to--leading logarithmic accuracy and we compare the results to those for the well-known pTp_T distribution, identifying important physical differences between the two cases. We also test our resummed result at the two-loop level by comparing its expansion to order αs2\alpha_s^2 with the corresponding fixed-order results and find agreement with our expectations.Comment: 30 pages, 3 figures, JHEP class included. Final version published in JHE

    Reutilización de botellas de plástico en la localidad de Saladas

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    El proyecto de extensión “Construir reciclando”, financiado por la Secretaría de Políticas Universitarias fue realizado por alumnos del Profesorado en Ciencias Químicas y del Ambiente junto a docentes de la FaCENA - UNNE. El mismo estuvo destinado a crear una actitud comprometida con el medio ambiente. El reciclado es un tema que nos afecta a todos por igual. El medio ambiente, los recursos naturales y el ser humano con todas sus actividades están estrechamente relacionados y si alguno de estos componentes influye de manera positiva o negativa sobre el/los otro/s, todo el sistema va a notar ese cambio. Este trabajo se realizó con alumnos y docentes de la Escuela Técnica Dr. Juan Gregorio Pujol, de la localidad de Saladas de la provincia de Corrientes. Las actividades desarrolladas se orientaron hacia la elaboración de ladrillos ecológicos como así también a la confección de “puff ” a partir de botellas de plástico descartable.Fil: Giménez, Andrea F.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Sotelo Gasfrascoli, Lucía V.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Legizamón, Andrea M.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Coronel, Silvia C.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: López, Romina N.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Booth, Yanina M. R.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: López, Antonella E.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Lasala, César G.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Peyrano, Felicitas. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Vallejos, Margarita. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Chaves, María Guadalupe. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Avanza, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Acevedo, Belén Andrea. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentin

    Ataques de seguridad en las FPGAs y cómo prevenirlos.

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    Este documento es un estudio de algunos ataques de seguridad a los dispositivos lógicos de propósito general, concretamente a las FPGA (del inglés Field Programmable Gate Array), que se han encontrado. Actualmente es muy común escuchar hablar de este tipo de dispositivos, las FPGA´s y sus múltiples contextos de aplicación, entre los que se encuentran procesos de aceleración, criptografía, entre otros. Sin embargo, se desconocen los ataques que éstas pueden sufrir. Con este documento se pretende mostrar algunos de los ataques conocidos y algunas formas de prevenirlos
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