43 research outputs found

    Enhanced thylakoid photoprotection can increase yield and canopy radiation use efficiency in rice

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    High sunlight can raise plant growth rates but can potentially cause cellular damage. The likelihood of deleterious effects is lowered by a sophisticated set of photoprotective mechanisms, one of the most important being the controlled dissipation of energy from chlorophyll within photosystem II (PSII) measured as non-photochemical quenching (NPQ). Although ubiquitous, the role of NPQ in plant productivity remains uncertain because it momentarily reduces the quantum efficiency of photosynthesis. Here we used plants overexpressing the gene encoding a central regulator of NPQ, the protein PsbS, within a major crop species (rice) to assess the effect of photoprotection at the whole canopy scale. We accounted for canopy light interception, to our knowledge for the first time in this context. We show that in comparison to wild-type plants, psbS overexpressors increased canopy radiation use efficiency and grain yield in fluctuating light, demonstrating that photoprotective mechanisms should be altered to improve rice crop productivity

    Stimulating photosynthetic processes increases productivity and water use efficiency in the field

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    Previous studies have demonstrated that independent stimulation of either electron transport or RuBP regeneration can increase the rate of photosynthetic carbon assimilation and plant biomass. In this paper, we present evidence that a multi-gene approach to simultaneously manipulate these two processes provides a further stimulation of photosynthesis. We report on the introduction of the cyanobacterial bifunctional enzyme fructose-1, 6- bisphosphatase/sedoheptulose-1,7-bisphosphatase or overexpression of the plant enzyme sedoheptulose-1,7-bisphosphatase, together with expression of the red algal protein cytochrome c6, and show that a further increase in biomass accumulation under both glasshouse and field conditions can be achieved. Furthermore, we provide evidence that stimulation of both electron transport and RuBP regeneration can lead to enhanced intrinsic water use efficiency under field conditions

    Fracture following lower limb lengthening in children: A series of 58 patients

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    International audienceIntroduction: Fracture is one of the main complications following external fixator removal used in cases of progressive lower limb lengthening; rates as high as 50% are found in the literature. The aim of this study was to determine the factors influencing this complication. Materials and methods: One hundred and eleven cases of lower limb lengthening were performed in 58 patients (40 femurs and 71 tibias). The mean age at surgery was 10.1 years old. Lengthening was performed in all cases with an external fixator alone, associated in 39.6% of cases with intramedullary nailing. The patients were divided into three groups according to disease etiology (congenital, achondroplasia and other). The fractures were classified according to the Simpson classification. Results: Twenty fractures were recorded (18%). Sixteen fractures were found in patients with congenital disease, four with achondroplasia and none in the group of other etiologies. The fracture was more often in the femur (27.5%) than in the tibia (12.7%). Discussion: The rate of fracture is influenced by different factors depending on the etiology of disease. In congenital diseases, the fracture rate is higher when there is lengthening of more than 15% of the initial length and a delay between surgery and the beginning of lengthening of less than 7 days. In patients with achondroplasia, the influence of a relative percentage of lengthening is less important than in those with congenital disease. However, to avoid fractures, lengthening should not be started in children under the age of nine. Moreover, lengthening should begin at least 7 days after the fixator has been placed. Type of study: Retrospective. Level of evidence: Level IV. (C) 2012 Elsevier Masson SAS. All rights reserved

    The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis

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    International audienceIntroduction: Kinematic alignment (KA) technique is an alternative technique for positioning a TKA, which aims a patient-specific implant positioning in order to reproduce the pre-arthritic knee anatomy. Because reliability in implant positioning is of interest to obtain reproducible good functional results, our study tests the hypothesis that the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically aligned femoral component are similar. Methods: Preoperative knee magnetic resonance imaging (MRI) and postoperative knee computed tomography (CT) of 13 patients implanted with a KA Persona TKA (Zimmer, Warsaw, USA) using manual instrumentation (kinematically-aligned TKA procedure pack, Zimmer Biomet, Warsaw, USA) were segmented to create 3D femoral models. The kinematic alignment position of the femoral component was planned on the 3D model created from the preoperative MRI. Differences in the positions of the planned and surgically implanted kinematically-aligned femoral component were determined with in-house analysis software. Results: The average differences between the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically-aligned femoral component were inferior to 1mm and no statistically significant. In terms of variability, 62% (8/13) of performed implants matched all four positions within 1.5mm, and the maximum difference was 3mm. Conclusion: In this small series, intraoperative kinematic positioning of the femoral component with the specific manual instrumentation closely matched the planned position, which suggests that this technique reliably aligned the flexion-extension axis of the femoral component to the cylindrical axis. (C) 2017 Elsevier Masson SAS. All rights reserved

    Pathogen reduction through additive-free short-wave UV light irradiation retains the optimal efficacy of human platelet lysate for the expansion pf human bone marrow mesenchymal stem cells

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    Pathogen reduction through additive-free short-wave UV light irradiation retains the optimal efficacy of human platelet lysate for the expansion pf human bone marrow mesenchymal stem cells. 43rd Annual Meeting of EBM

    A standardized and characterized clinical grade human platelet lysate for optimized expansion of human bone marrow mesenchymal stem cells

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    A standardized and characterized clinical grade human platelet lysate for optimized expansion of human bone marrow mesenchymal stem cells. 43rd Annual Meeting of the European Society for Blood and Marrow Transplantation (EBMT

    Modeling the interfaces in masonry structures

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    International audienceThis chapter deals with some models for interfaces in the case of masonry structures. Some experimental studies are recalled in the first part. In the second part, four interface models are presented
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