Formas de fósforo em folhas e suas relações com a composição do mosto e a produção em videiras

The objective of this work was to evaluate phosphorus forms in grape leaves and their relationships with must composition and yield in grapevines grown in a Typic Hapludalf with different available P contents. Two experiments were carried out with Vitis vinifera cultivars, one with 'Tannat' and the other with 'Cabernet Franc' grapes. Experiment 1 consisted of two vineyards of 'Tannat', with the following P content in the soil: V1, 11.8 mg kg-1 P; and V2, 34.6 mg kg-1 P. Experiment 2 consisted of two vineyards of 'Cabernet Franc', with the following P content in the soil: V1, 16.0 mg kg-1 P; and V2, 37.0 mg kg-1 P. Leaves were collected at flowering (FL) and veraison (V), and, after their preparation, P forms were evaluated. Yield and must composition were assessed. The highest yield was observed in V2 of experiment 1 and in V2 of experiment 2. Total P content and P forms in leaves at FL and V have no relationship with yield parameters; however, total P content in leaves has a relationship with anthocyanin content in the must of 'Tannat' grapevines. Therefore, P fractionation in leaves predicts neither grapevine yield nor must composition.O objetivo deste trabalho foi avaliar as formas de fósforo em folhas e suas relações com a composição do mosto e a produção em videiras cultivadas em um Argissolo Vermelho distrófico típico, com diferentes teores de P disponível. Dois experimentos foram realizados com cultivares de Vitis vinifera, um com uvas 'Tannat' e outro com 'Cabernet Franc'. O experimento 1 consistiu de dois vinhedos de 'Tannat', com os seguintes teores de fósforo no solo: V1, 11,8 mg kg-1 de P; e V2, 34,6 mg kg-1 de P. O experimento 2 consistiu de dois vinhedos de 'Cabernet Franc', com os seguintes teores de fósforo no solo: V1, 16,0 mg kg-1 de P; e V2, 37,0 mg kg-1 de P. Coletaram-se as folhas ao florescimento (FL) e ao início da maturação (IM), e, após a preparação delas, analisaram-se as formas de P. A produtividade e a composição do mosto foram avaliadas. A maior produtividade foi observada no V2 do experimento 1 e no V2 do experimento 2. O teor total de P e suas formas nas folhas ao FL e IM não apresentam relação com os parâmetros produtivos; no entanto, o teor de P total nas folhas apresenta relação com o teor de antocianinas no mosto de videiras 'Tannat'. Portanto, o fracionamento de P nas folhas não prediz a produtividade da videira nem a composição do mosto

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Carbon stabilization and saturation in a no-till subtropical soil in long-term

Solos subtropicais sob plantio direto associado a sistemas de culturas diversificados podem atuar como um grande sumidouro de C. No entanto, pouco se sabe sobre a saturação de C nessas condições, especialmente em Argissolos resilientes. Dois estudos foram conduzidos em experimento de longa duração (36 anos) sobre um Argissolo vermelho no sul do Brasil, os quais tiveram como objetivo (i) avaliar o efeito de sistemas de culturas a base de leguminosas de cobertura de solo em plantio direto no déficit de saturação de C na matéria orgânica associada aos minerais (<20μm, DSCmoM) e na capacidade remanescente de estabilização de C (estudo 1); (ii) investigar o efeito do DSCmoM na estabilização do C recém adicionado, proveniente de resíduos vegetais de diferentes qualidades e enriquecidos com 13C, em diferentes frações da matéria orgânica do solo (MOS), em um experimento de incubação no campo por 15 meses (estudo 2). Diferentes frações da MOS foram isoladas por fracionamento físico, e a avaliação de C e do isótopo 13C derivado dos resíduos foi realizada nessas frações da MOS no primeiro e no segundo estudo, respectivamente. Os principais resultados indicam que os sistemas de cultura à base de leguminosas de cobertura de solo (lablab, guandu e feijão-caupi) com alto adição de C resultaram em alto acúmulo de C na moM e em níveis de C nesta fração próximos a saturação, principalmente na camada de 0-2,5 cm. Além disso, foi observado um decréscimo no DSCmoM em todas as camadas de solo até 20 cm. A capacidade remanescente de estabilização de C na moM diminuiu 90-97% quando comparada ao solo descoberto na camada de 0-2,5 cm. A maior estabilização do13C na moM foi observado no C derivado da ervilhaca do que da aveia na camada superficial do solo (0-2,5 cm), mas apenas quando o solo apresentava alta capacidade de estabilização de C (níveis alto e muito alto de DSCmoM). Quando a estabilização do C novo na moM foi limitada pela saturação, a incorporação do 13C foi intensificada nas frações intra e inter-agregados. Os resultados destacam que os fatores sistemas de cultivos diversificados, o DSCmoM e a qualidade dos resíduos impulsionam a estabilização do C nas camadas superficiais do solo sob plantio direto. Estudos futuros de incubação investigando o efeito da DSCmoM na migração de C no perfil de solo sob plantio direto a longo prazo são necessários para entender melhor a dinâmica de sequestro de C neste ambiente.Subtropical no-till soils combined with diversified cropping systems can act as a large C sink. However, very little is known about the C saturation in these conditions, especially in resilient Acrisols. Two studies were performed based on a long-term (36 years) no-till experiment on a Acrisol in Southern Brazil .These studies aimed to evaluate the (i) effect of long-term no-till legume-based cropping systems on C saturation deficits in mineral-associated organic matter (<20μm, CSDmOM) and the remaining capacity of C stabilization (study 1); (ii) investigate the effect of CSDmOM on C stabilization from different quality 13C-labeled litters in different fractions of soil organic matter (SOM) in a 15 months in situ experiment (study 2). Different fractions of SOM were isolated by physical fractionation, and the assessment of C and litter-derived 13C in these SOM fractions were performed in the first and second study, respectively. The main findings indicate that legume-based cropping systems with high C input led to high C stabilization in mineral-associated organic matter (mOM) and resulted in C levels in this fraction close to saturation, mainly in the 0-2.5 cm soil layer. Also, a decrease of CSDmOM was observed in all soil layers up to 20 cm. The capacity to further stabilizes carbon in mOM decreased by 90-97% when compared to bare soil in the 0-2.5 cm layer. Higher C stabilization in the mOM was observed for vetch-than oat- derived 13C in the 0-2.5 cm, but only when soil presents a high capacity of C stabilization in the mOM fraction (high and very high levels of CSDmOM). When the litter-derived C stabilization in mOM was limited by its previous C level close to saturation, 13C incorporation was intensified in the intra- and inter-aggregate SOM fractions. The results highlight that the factors diversified cropping system, CSDmOM and residue quality drive the C stabilization in surface soil layers of no- till subtropical soils. Future in situ studies investigating the effect of C saturation on migration of C in profile of long-term no-till subtropical soils are required to better understand the dynamic of C sequestration in this environment

Residual and immediate effect after 16 applications of organic sources on yield and nitrogen use efficiency in black oat and corn

Soils with a long-term history of animal manure application exhibit higher residual effects of nitrogen (N) in soil and can affect the efficiency with which N will be used. This study aimed to evaluate how the immediate and residual effect of 16 applications of animal manure reflects on yields of black oat and corn rotation system, as well as N use efficiency. The study was carried out in no-tillage from 2004 to 2016 in Brazil. The treatments were pig slurry (PS), dairy slurry (DS), pig deep-litter (PL), mineral fertilizer (MF), and control (C). Prior to the sowing of black oat, in which 16 animal manure applications had already been made, an area of the soil was delimited where the treatments were not applied. This area was referred to as unfertilized (U) soil. Applications were carried out in the remaining area and were referred to as fertilized (F) soil. The highest dry matter yield and N accumulation in black oat and corn were found in F soils treated with DS and PL, respectively. In corn, the highest grain yield and N accumulation in grains were found with DS and PS. In U soil, the 16 applications (of DS especially) resulted in yields and N accumulation greater than the control and MF, but lower than those in F. The highest N use efficiency was found with DS. The history of animal manure applications was not enough to rule out additional applications in the following years