3,040 research outputs found

    Nova perspectiva de custo de produção na agropecuária: proposta de avaliação para sistemas de integração lavoura-pecuária-floresta (iLPF)

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    O Brasil está entre os maiores produtores e exportadores de grãos do mundo. Entretanto, apesar de seu sucesso, o setor agropecuário está passando por mudanças em sua estrutura e modelos alternativos de organização da estrutura produtiva agropecuária baseados no pilar: aumento da produção/produtividade e preservação ambiental passaram a ter grande destaque. É nesse contexto que se encontram os sistemas produtivos baseados no modelo de sistemas integrados de produção, como a integração Lavoura-Pecuária-Floresta (iLPF), sistemas que têm como princípios básicos a produção sustentável por meio da interação de atividades agrícolas, pecuárias e florestais, realizados em uma mesma área. A literatura fornece poucos exemplos de métodos e ferramentas desenvolvidas para a avaliação destes sistemas. Este trabalho traz contribuições importantes para compreender uma das partes mais críticas destes sistemas, que é o custo de produção. Apresentamos uma nova proposta de visualização dos custos de produção para o setor agropecuário que se baseia no sistema de custeio por atividades (Activity Based Costing) e apresentamos os benefícios que esta metodologia trouxe ao processo de gestão da propriedade e à tomada de decisão do produtor rural

    Effects of Repeated Stress on Distal Airway Inflammation, Remodeling and Mechanics in an Animal Model of Chronic Airway Inflammation

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    Background/Aims: Epidemiological studies suggest that stress has an impact on asthmatic exacerbations. We evaluated if repeated stress, induced by forced swimming, modulates lung mechanics, distal airway inflammation and extracellular matrix remodeling in guinea pigs with chronic allergic inflammation. Methods: Guinea pigs were submitted to 7 ovalbumin or saline aerosols (1-5 mg/ml during 4 weeks; OVA and SAL groups). Twenty-four hours after the 4th inhalation, guinea pigs were submitted to the stress protocol 5 times a week during 2 weeks (SAL-S and OVA-S groups). Seventy-two hours after the 7th inhalation, guinea pigs were anesthetized and mechanically ventilated. Resistance and elastance of the respiratory system were obtained at baseline and after ovalbumin challenge. Lungs were removed, and inflammatory and extracellular matrix remodeling of distal airways was assessed by morphometry. Adrenals were removed and weighed. Results: The relative adrenal weight was greater in stressed guinea pigs compared to non-stressed animals (p < 0.001). Repeated stress increased the percent elastance of the respiratory system after antigen challenge and eosinophils and lymphocytes in the OVA-S compared to the OVA group (p < 0.001, p = 0.003 and p < 0.001). Neither collagen nor elastic fiber contents were modified by stress in sensitized animals. Conclusions: In this animal model, repeated stress amplified bronchoconstriction and inflammatory response in distal airways without interfering with extracellular matrix remodeling. Copyright (C) 2011 S. Karger AG, Base

    Reação de cultivares de feijoeiro comum à mancha angular em casa de vegetação.

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    Foi avaliada a reação de 23 genótipos de feijoeiro comum (Phaseolus vulgaris) à mancha angular causada por Phaeoisariopsis griseola, utilizando os isolados monospóricos Ig 664 e Ig 669, caracterizados como os patótipos 63.23 e 63.19, respectivamente. Quatorze dias após a semeadura (estádio V3), as plantas foram inoculadas com uma suspensão contendo 2,5 x 10(4) conídios/mL, nas faces adaxial e abaxial da primeira folha trifoliolada. A avaliação dos sintomas foi efetuada aos 14 e 18 dias após a inoculação, utilizando-se uma escala variando de 1 (sem sintomas) a 9 ( > 25% da área foliar com lesões de mancha angular). Das cultivares analisadas, BRS Valente, CNFC 10281, CNFP 10138, BRS Grafite, BRS Requinte, BRS Pontal, MAR 02, Cornell 49-242 e AND 277 foram resistentes aos dois isolados. As cultivares Carioca Rubi, CNFC 9504, CNFC 10150 e Soberano foram suscetíveis aos dois patótipos testados. O patótipo 63.23 foi o mais virulento. As novas fontes de resistência à mancha angular identificadas neste trabalho podem ser utilizadas em programas de melhoramento do feijoeiro comum, que visem incorporar resistência em novas cultivares

    Inhalation of the prodrug PI3K inhibitor CL27c improves lung function in asthma and fibrosis

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    PI3K activation plays a central role in the development of pulmonary inflammation and tissue remodeling. PI3K inhibitors may thus offer an improved therapeutic opportunity to treat non-resolving lung inflammation but their action is limited by unwanted on-target systemic toxicity. Here we present CL27c, a prodrug pan-PI3K inhibitor designed for local therapy, and investigate whether inhaled CL27c is effective in asthma and pulmonary fibrosis. Mice inhaling CL27c show reduced insulin-evoked Akt phosphorylation in lungs, but no change in other tissues and no increase in blood glycaemia, in line with a local action. In murine models of acute or glucocorticoid-resistant neutrophilic asthma, inhaled CL27c reduces inflammation and improves lung function. Finally, inhaled CL27c administered in a therapeutic setting protects from bleomycin-induced lung fibrosis, ultimately leading to significantly improved survival. Therefore, local delivery of a pan-PI3K inhibitor prodrug reduces systemic on-target side effects but effectively treats asthma and irreversible pulmonary fibrosis

    Dynamics of early establishment of SARS-CoV-2 VOC Omicron lineages in Minas Gerais, Brazil

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    Brazil is one of the nations most affected by Coronavirus disease 2019 (COVID-19). The introduction and establishment of new virus variants can be related to an increase in cases and fatalities. The emergence of Omicron, the most modified SARS-CoV-2 variant, caused alarm for the public health of Brazil. In this study, we examined the effects of the Omicron introduction in Minas Gerais (MG), the second-most populous state of Brazil. A total of 430 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) samples from November 2021 to June 2022 from Belo Horizonte (BH) city were sequenced. These newly sequenced genomes comprise 72% of all previously available SARS-CoV-2 genomes for the city. Evolutionary analysis of novel viral genomes reveals that a great diversity of Omicron sublineages have circulated in BH, a pattern in-keeping with observations across Brazil more generally. Bayesian phylogeographic reconstructions indicate that this diversity is a product of a large number of international and national importations. As observed previously, São Paulo state is shown as a significant hub for viral spread throughout the country, contributing to around 70% of all viral Omicron introductions detected in MG

    The Fluorescence Detector of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics Research Section
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