419 research outputs found

    Effect of Pruning Severity on Yield, Drying Time and Wages in Flame Seedless Dry-on-vine and Traditional Raisin Production Systems in Argentina

    Get PDF
    Raisin grapes are potentially more profitable than wine grapes in San Juan, Argentina, although the traditional system of grape drying requires an extensive use of costly labour. Production costs might be reduced by adopting the dry-on-vine (DOV) raisin-making system, but the feasibility of DOV in Argentina has not been assessed, and neither have the costs and pruning schemes. Thus we determined drying time and yields, estimated wages per hectare, and determined the influence of pruning severity on Flame Seedless raisin grapes. A completely random design with six treatments and six replicates was used in the 2013 to 2016 seasons. The treatments comprised differences in the nodes per cane, nodes per vine,distribution of nodes, and sugar content. Descriptive statistics and variance analysis were calculated for fresh fruit weight, dry fruit weight, drying ratio and drying time. The leaf area and its relationship with dried fruit weight also were calculated. These data were processed with the Infostat program. The DOV system demands between 11 and 31 additional days during the drying period and reduces labour costs by between 38% and 64% compared to the traditional system. Long pruning with the same load of buds is better. Furthermore, the DOV system is not associated with a lower production and thus appears to be a financially sustainable alternative to traditional production systems for Flame Seedless raisin grape producers in Argentina

    Rural-urban migration in d-dimensional lattices

    Full text link
    The rural-urban migration phenomenon is analyzed by using an agent-based computational model. Agents are placed on lattices which dimensions varying from d=2 up to d=7. The localization of the agents in the lattice define their social neighborhood (rural or urban) not being related to their spatial distribution. The effect of the dimension of lattice is studied by analyzing the variation of the main parameters that characterizes the migratory process. The dynamics displays strong effects even for around one million of sites, in higher dimensions (d=6, 7).Comment: 9 pages, 7 figures, to be published in International Journal of Modern Physics C 1

    NGC 6438 : A triple system?

    Get PDF
    We provide photographic and photoelectric information as well as CCD imaging and medium resolution spectroscopy on this system located at a distance of -32 Mpc. The SO galaxy has twisted isophotes which also show changes in the ellipticity. Profiles toward the north of this galaxy are 0.1 and 0.2 magnitudes brighter in the B and V bands respectively, than in any other direction, probably due to the presence of dust in the Irregular system. Several blue regions (B-V = 0.26 - 0.40) are found in the Irregular object indicating ongoing star formation. One of these regions is located in an extreme of the northern arm, its luminosity being similar to that of the nucleus which is very close to it. Analysis of the spectra shows typical absorption lines and a weak [Nil] emission in the SO galaxy whereas Ha, [Nil] and [SII] emission lines are observed both in the nucleus and in the blue region mentioned above. We determine a high reddening E(B-V) = 1.4 in the nuclear region of this system. Rotation curves show a different behavior for the nucleus and the blue region, which have Vmax >180 km/sec and Vmax = 80 km/sec respectively. All tins evidence could support the idea that NGC 6438 is an interacting triplet, one SO galaxy and two disk galaxies undergoing a merger.Asociación Argentina de Astronomí

    Produção de anticorpos monoclonais anti-cisticercos de Taenia crassiceps com reatividade cruzada com antígenos de Taenia solium

    Get PDF
    We describe the production of the potential monoclonal antibodies (MoAbs) using BALB/c mice immunized with vesicular fluid (VF)-Tcra (T. crassiceps) antigen. Immune sera presented anti-VF-Tcra (É descrita a produção de potenciais anticorpos monoclonais (MoAbs) usando camundongos BALB/c imunizados com antígenos de líquido vesicular de T. crassiceps (VF-Tcra). O soro imune apresentou anticorpos IgM e IgG anti-VF-Tcra para os peptídeo

    Benefícios da adubação verde sobre a simbiose micorrízica e a produtividade de batata-doce.

    Get PDF
    Plantio das leguminosas e da batata doce. Produtividade da batata doce e simbiose micorrízica.bitstream/CNPAB-2010/27139/1/cot014.pd

    The use of gene expression to unravel the single and mixture toxicity of abamectin and difenoconazole on survival and reproduction of the springtail Folsomia candida

    Get PDF
    Pesticides risk assessments have traditionally focused on the effects on standard parameters, such as mortality, reproduction and development. However, one of the first signs of adverse effects that occur in organisms exposed to stress conditions is an alteration in their genomic expression, which is specific to the type of stress, sensitive to very low contaminant concentrations and responsive in a few hours. The aim of the present study was to evaluate the single and binary mixture toxicity of commercial products of abamectin (Kraft® 36 EC) and difenoconazole (Score® 250 EC) to Folsomia candida. Laboratory toxicity tests were conducted to access the effects of these pesticides on springtail survival, reproduction and gene expression. The reproduction assays gave EC50 and EC10 values, respectively, of 6.3 and 1.4 mg a.s./kg dry soil for abamectin; 1.0 and 0.12 mg a.s./kg dry soil for Kraft® 36 EC; and 54 and 23 mg a.s./kg dry soil for Score® 250 EC. Technical difenoconazole did not have any effect at the concentrations tested. No significant differences in gene expression were found between the abamectin concentrations tested (EC10 and EC50) and the solvent control. Exposure to Kraft® 36 EC, however, significantly induced Cyp6 expression at the EC50 level, while VgR was significantly downregulated at both the EC10 and EC50. Exposure to the simple pesticide mixture of Kraft® 36 EC + Score® 250 EC caused significant up regulation of ABC transporter, and significant down regulation of VgR relative to the controls. GABA receptor also showed significant down-regulation between the EC10 and EC50 mixture treatments. Results of the present study demonstrate that pesticide-induced gene expression effects precede and occur at lower concentrations than organism-level responses. Integrating "omic" endpoints in traditional bioassays may thus be a promising way forward in pesticide toxicity evaluations

    Warm stellar matter with deconfinement: application to compact stars

    Full text link
    We investigate the properties of mixed stars formed by hadronic and quark matter in β\beta-equilibrium described by appropriate equations of state (EOS) in the framework of relativistic mean-field theory. We use the non- linear Walecka model for the hadron matter and the MIT Bag and the Nambu-Jona-Lasinio models for the quark matter. The phase transition to a deconfined quark phase is investigated. In particular, we study the dependence of the onset of a mixed phase and a pure quark phase on the hyperon couplings, quark model and properties of the hadronic model. We calculate the strangeness fraction with baryonic density for the different EOS. With the NJL model the strangeness content in the mixed phase decreases. The calculations were performed for T=0 and for finite temperatures in order to describe neutron and proto-neutron stars. The star properties are discussed. Both the Bag model and the NJL model predict a mixed phase in the interior of the star. Maximum allowed masses for proto-neutron stars are larger for the NJL model (1.9\sim 1.9 M_{\bigodot}) than for the Bag model (1.6\sim 1.6 M_{\bigodot}).Comment: RevTeX,14 figures, accepted to publication in Physical Review

    The importance of back contact modification in Cu2ZnSnSe4 solar cells: The role of a thin MoO2 layer

    Full text link
    Cu2ZnSn(SxSe1-x)4 (CZTSSe) photovoltaic absorbers could be the earth-abundant and low toxicity replacement for the already commercialized CuIn1-xGaxSe2 (CIGS) thin film technology. In order to make this possible, specific research efforts applied to the bulk, front and back interfaces must be performed with the aim of improving CZTSSe performance. In this paper the importance of back contact modification to obtain high efficiency Cu2ZnSnSe4 (CZTSe) solar cells and to increase a paramount and limiting parameter such as VOC is highlighted. Several Mo configurations (monolayer, bi-layer and tri-layer) with different electrical and morphological properties are investigated in CZTSe solar cells. An optimum tri-layer configuration in order to minimize overselenization of the back contact during thermal annealing while keeping reasonable electrical features is defined. Additionally, a thin intermediate MoO2 layer that results in a very effective barrier against selenization and innovative way to efficiently assist in the CZTSe absorber sintering is introduced. The use of this layer enhances grain growth and subsequently the efficiency of solar cells increases via major VOC and FF improvement. An efficiency increase from 7.2% to 9.5% is obtained using a Mo tri-layer with a 20 nm intermediate MoO2 layerThis research was supported by the Framework 7 program under the project KESTCELLS (FP7-PEOPLE-2012-ITN-316488), by MINECO (Ministerio de Economía y Competitividad de España) under the SUNBEAM project (ENE2013-49136-C4-1-R), and by European Regional Development Founds (ERDF, FEDER Programa Competitivitat de Catalunya 2007–2013). Authors from IREC and the University of Barcelona belong to the M-2E (Electronic Materials for Energy) Consolidated Research Group and the XaRMAE Network of Excellence on Materials for Energy of the “Generalitat de Catalunya”. M.E-R. thanks the MINECO for the FPI-MINECO (BES-2011-045774), Y.S. for the PTA fellowship (PTA2012-7852-A), SG for the FPI fellowship (BES-2014-068533), M.P. for the MINECO postdoctoral fellow (FPDI-2013-18968), E.S. and R.C. for the “Ramon y Cajal” fellowship (RYC-2011-09212) and (RYC-2011-08521) respectively, and H.X. thanks the “China Scholarship Council” fellowship (CSC Nº 201206340113

    The importance of the mixed phase in hybrid stars built with the Nambu-Jona-Lasinio model

    Full text link
    We investigate the structure of hybrid stars based on two different constructions: one is based on the Gibbs condition for phase coexistence and considers the existence of a mixed phase (MP), and the other is based on the Maxwell construction and no mixed phase is obtained. The hadron phase is described by the non-linear Walecka model (NLW) and the quark phase by the Nambu-Jona-Lasinio model (NJL). We conclude that the masses and radii obtained are model dependent but not significantly different for both constructions.Comment: 8 pages, 7 figures, 3 table

    Microbial activity in a degraded Latosol treated with sewage sludge

    Get PDF
    The degraded soil shows, in general, poor biological activity, considering its physical characteristics, low fertility and organic matter, mainly due to removal or degradation of its superficial layer. The sewage sludge, due to its high content of easily decomposed organic matter can be an alternate source of organic residues and combined to its high content of the principal nutrients for the plants can be an important factor to promote biological activities in degraded soil. In order to study the actions of the sewage sludge in the recovery of a degraded Latosol, the carbon in the microbial biomass (Cmic), the carbon released CO2 (C-CO2) and the relation between microbial and organic carbon (Cmic/Corg) were used as indicators of the effects. To do so, two doses (30 and 60 Mg ha-1) of sewer slime applied in topdressing and incorporated together with a mineral fertilizer treatment, using the eucalyptus as a test crop. A completely randomized design with 4 treatments and 4 repetitions was used. The sewage sludge promoted increase of liberated C-CO2 and the Cmic, which constitute the adequate quality indicators for monitoring the soil recovery.Em geral, os solos degradados se apresentam com fraca atividade biológica, tendo em vista suas características físicas, baixa fertilidade e teores de matéria orgânica, devido principalmente à remoção ou degradação de sua camada superficial. O elevado teor de matéria orgânica facilmente decomposta do lodo de esgoto, que é uma fonte alternativa de resíduos orgânicos, aliado à sua elevada taxa dos principais elementos nutrientes às plantas, pode ser um fator importante do retorno ou incremento da atividade biológica dos solos degradados. Com a finalidade de se estudar as ações do lodo de esgoto na recuperação de um Latossolo degradado, utilizaram-se, como indicadores dos efeitos, o carbono na biomassa microbiana (Cmic), o carbono do CO2 (C-CO2) liberado e a relação entre o carbono microbiano e o carbono orgânico (Cmic/Corg); para isto, foram definidas duas doses de lodo de esgoto aplicadas em cobertura e incorporada, de 30 e 60 Mg ha-1 à base seca, juntamente com um tratamento com fertilizante mineral, utilizando-se o eucalipto como cultura teste. O delineamento experimental foi o inteiramente casualizado, com 4 tratamentos e 4 repetições. O lodo de esgoto promove aumento do C-CO2 liberado e do Cmic, os quais constituem indicativos de qualidade adequados ao monitoramento da recuperação do solo.19519
    corecore