384 research outputs found

    Influence of storage environment on maize grain: CO2 production, dry matter losses and aflatoxins contamination

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    Poor storage of cereals, such as maize can lead to both nutritional losses and mycotoxin contamination. The aim of this study was to examine the respiration of maize either naturally contaminated or inoculated with Aspergillus flavus to examine whether this might be an early and sensitive indicator of aflatoxin (AF) contamination and relative storability risk. We thus examined the relationship between different interacting storage environmental conditions (0.80–0.99 water activity (aw) and 15–35°C) in naturally contaminated and irradiated maize grain + A. flavus on relative respiration rates (R), dry matter losses (DMLs) and aflatoxin B1 and B2 (AFB1-B2) contamination. Temporal respiration and total CO2 production were analysed by GC-TCD, and results used to calculate the DMLs due to colonisation. AFs contamination was quantified at the end of the storage period by HPLC MS/MS. The highest respiration rates occurred at 0.95 aw and 30–35°C representing between 0.5% and 18% DMLs. Optimum AFs contamination was at the same aw at 30°C. Highest AFs contamination occurred in maize colonised only by A. flavus. A significant positive correlation between % DMLs and AFB1 contamination was obtained (r = 0.866, p < 0.001) in the irradiated maize treatments inoculated with A. flavus. In naturally contaminated maize + A. flavus inoculum loss of only 0.56% DML resulted in AFB1 contamination levels exceeding the EU legislative limits for food. This suggests that there is a very low threshold tolerance during storage of maize to minimise AFB1 contamination. This data can be used to develop models that can be effectively used in enhancing management for storage of maize to minimise risks of mycotoxin contamination

    Effectiveness and safety of iodopovidone in an experimental pleurodesis model

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    OBJECTIVES: Chemical pleurodesis is an important therapeutic tool to control recurrent malignant pleural effusion. Among the various sclerosing agents, iodopovidone is considered effective and safe. However, in a recent study, ocular changes were described after iodopovidone was used in recurrent pneumothorax. The aim of the study was to evaluate the efficacy and morbidity of iodopovidone pleurodesis in an experimental model. METHODS: New Zealand rabbits were submitted to intrapleural injection of iodopovidone at concentrations of 2%, 4% and 10%. Biochemical (lactic dehydrogenase, proteins, triiodothyronine, free thyroxine, urea and creatinine) and immunological (Interleukin-8 [IL-8], VEGF and TGFβ) parameters were measured in the pleural fluid and blood. After 1, 3, 7, 14 and 28 days, groups of animals were euthanized, and macro- (pleura) and microscopic (pleura and retina) analyses were performed. RESULTS: An early pleural inflammatory response with low systemic repercussion was observed without corresponding changes in thyroid or renal function. The higher concentrations (4% and 10%) correlated with greater initial exudation, and maximum pleural thickening was observed after 28 days. No changes were observed in the retinal pigment epithelium of the rabbits. CONCLUSION: Iodopovidone is considered to be an effective and safe sclerosing agent in this animal model. However, its efficacy, tolerance and safety in humans should be further evaluated

    Il Questionario «Experiences In Close Relationships» (Ecr) Per la Valutazione dell’attaccamento negli Adulti: Ampliamento Delle Evidenze di Validità per la Versione Italiana.

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    Objective Improvement in the assessment of adult attachment are mandatory, if research on attachment and psychopathology is to make substantial progress. In a preliminary study, the Italian version of the questionnaire ‘Experiences in Close Relationships’ (ECR) demonstrated good psychometric properties. We aimed at collecting further evidence of the validity of the questionnaire. Methods We included in the study subjects of 18-65 years, with at least junior high school degree. We examined convergent validity on 364 subjects, with the Relationship Questionnaire (RQ) as a criterion measure. In these subjects, we also compared three different Italian translations of item 21 with regard to factorial validity and internal consistency. Data from these subjects and other 386 subjects were used to compute norms for scale scores, stratified for age and gender. Results Internal consistency was satisfactory. Cronbach’s alpha was. 89 for both the ‘Anxiety’ and ‘Avoidance’ scales. A new Italian version of item 21 showed better psychometric properties as compared to the preceding version. A six-factor solution was obtained, explaining 61.3% of total variance. Then, factor scores were computed with the regression method, and a second-order factor analysis was performed. A two-factor solution was obtained, and the factors were clearly interpretable as ‘anxiety’ and ‘avoidance’. The pattern of correlations between ECR and RQ was as hypothesised, and the ECR was also found to possess good classification properties. Conclusion The Italian version of the ECR was confirmed to be reliable and valid. It might be useful for Italian researchers interested in adult attachment

    Geologic Carbon Sequestration in the Illinois Basin: Numerical Modeling to Evaluate Potential Impacts

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    US Department of Energy via the Regional Partnership Program, DE-FC26-05NT42588 and USEPA STAR grant number 488220Ope

    RVA. 3-D Visualization and Analysis Software to Support Management of Oil and Gas Resources

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    A free software application, RVA, has been developed as a plugin to the US DOE-funded ParaView visualization package, to provide support in the visualization and analysis of complex reservoirs being managed using multi-fluid EOR techniques. RVA, for Reservoir Visualization and Analysis, was developed as an open-source plugin to the 64 bit Windows version of ParaView 3.14. RVA was developed at the University of Illinois at Urbana-Champaign, with contributions from the Illinois State Geological Survey, Department of Computer Science and National Center for Supercomputing Applications. RVA was designed to utilize and enhance the state-of-the-art visualization capabilities within ParaView, readily allowing joint visualization of geologic framework and reservoir fluid simulation model results. Particular emphasis was placed on enabling visualization and analysis of simulation results highlighting multiple fluid phases, multiple properties for each fluid phase (including flow lines), multiple geologic models and multiple time steps. Additional advanced functionality was provided through the development of custom code to implement data mining capabilities. The built-in functionality of ParaView provides the capacity to process and visualize data sets ranging from small models on local desktop systems to extremely large models created and stored on remote supercomputers. The RVA plugin that we developed and the associated User Manual provide improved functionality through new software tools, and instruction in the use of ParaView-RVA, targeted to petroleum engineers and geologists in industry and research. The RVA web site (http://rva.cs.illinois.edu) provides an overview of functions, and the development web site (https://github.com/shaffer1/RVA) provides ready access to the source code, compiled binaries, user manual, and a suite of demonstration data sets. Key functionality has been included to support a range of reservoirs visualization and analysis needs, including: sophisticated connectivity analysis, cross sections through simulation results between selected wells, simplified volumetric calculations, global vertical exaggeration adjustments, ingestion of UTChem simulation results, ingestion of Isatis geostatistical framework models, interrogation of joint geologic and reservoir modeling results, joint visualization and analysis of well history files, location-targeted visualization, advanced correlation analysis, visualization of flow paths, and creation of static images and animations highlighting targeted reservoir features.Department of Energy, DOE award number DE-FE0005961Ope

    Abordagem aos números decimais e suas operações: a importância de uma “eficaz navegação” entre representações

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    Este artigo foca alguns aspectos e ideias de tarefas a serem exploradas com os alunos relativamente à multiplicação de números decimais, discutindo o conhecimento matemático para o ensino subjacente à preparação e à aplicação de tais tarefas. Discutem-se algumas representações dessa multiplicação e a importância de um rico e fundamentado conhecimento matemático para o ensino como promotor de um conhecimento matemático com significado, por parte dos alunos, por via de uma eficaz navegação entre representações. A escolha das representações pretende, aqui, tornar também evidente o motivo pelo qual, ao multiplicar dois números decimais, o número de casas decimais do produto é a soma dos factores. O texto tem por base um trabalho colaborativo desenvolvido ao longo dos últimos anos com professores do 1º ciclo do ensino básico (alunos com idade entre seis e nove anos), tendo como ponto de partida as discussões ocorridas ali, as reflexões subjacentes e as maiores dificuldades sentidas tanto pelos alunos, como pelos próprios professores. É de salientar que o facto de se abordarem conjuntamente representações dos números em decimais e fraccionários possibilita que os alunos se consciencializem de diferentes representações para um mesmo valor, o mesmo ocorrendo quando se utilizam diversas quantidades como unidades discretas, ou distintos tipos de unidades. Apenas se o professor for detentor de um sustentado conhecimento matemático para o ensino ele poderá recorrer a essas distintas representações de maneira construtiva e de modo a que tenham significado para os alunos

    Gamma Radiation from PSR B1055-52

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    The telescopes on the Compton Gamma Ray Observatory (CCRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data, a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics which distinguish this pulsar: the light curve is complex; there is no detectable unpulsed emission; the energy spectrum is flat, with no evidence of a sharp high-energy cutoff up to greater than 4 GeV. Comparisons of the gamma-ray data with observations at longer wavelengths show that no two of the known gamma-ray pulsars have quite the same characteristics; this diversity makes interpretation in terms of theoretical models difficult

    The hr1 and Fusion Peptide Regions of the Subgroup B Avian Sarcoma and Leukosis Virus Envelope Glycoprotein Influence Low pH-Dependent Membrane Fusion

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    The avian sarcoma and leukosis virus (ASLV) envelope glycoprotein (Env) is activated to trigger fusion by a two-step mechanism involving receptor-priming and low pH fusion activation. In order to identify regions of ASLV Env that can regulate this process, a genetic selection method was used to identify subgroup B (ASLV-B) virus-infected cells resistant to low pH-triggered fusion when incubated with cells expressing the cognate TVB receptor. The subgroup B viral Env (envB) genes were then isolated from these cells and characterized by DNA sequencing. This led to identification of two frequent EnvB alterations which allowed TVB receptor-binding but altered the pH-threshold of membrane fusion activation: a 13 amino acid deletion in the host range 1 (hr1) region of the surface (SU) EnvB subunit, and the A32V amino acid change within the fusion peptide of the transmembrane (TM) EnvB subunit. These data indicate that these two regions of EnvB can influence the pH threshold of fusion activation
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