33 research outputs found

    Effect of water stress on growth, water consumption and yield of silage maize under flood irrigation in semi-arid clilmate of Tadla (Morocco)

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    The field study of crops response to water stress is important to reduce agricultural water use in areas where the water resources are limited. This study was carried out during two growing periods of 2009 and 2010 in order to study the effect of water stress on crops growth, water consumption and dry matter yield of silage maize supplied with flood irrigation under the semiarid climate of Tadla in Morocco. Four to five irrigation treatments were applied at the rates of 100, 80, 60, 40 and 20% of ETc of maize. Soil water status, crop growth, leaf area index and above-ground biomass were measured. Results showed that growth dynamic of maize passes by three distinct phases: exponential phase, linear phase and a final phase. The irrigation deficit accelerates the senescence of the sheets and reduces the leaf area index. The maximum values of this parameter reached at flowering under the full irrigation treatment (100%ETc) are 5.1 and 4.8 in 2009 and 2010 respectively. Dry matter yields varied from 5.3 t/ha under T4 (40%ETc) to 16.4 t/ha under T1 (100% ETc) in 2009 whereas in 2010, it oscillated between 3.9 t/ha under T5 (20%ETc) to 12.5 t/ha under T1 (100%ETc). The actual evapotranspiration under T1 (100%ETc) was 478 mm and 463 mm in 2009 and 2010 respectively. According to the averaged values of two years, linear relationships have been evaluated between dry matter yield and water consumption ETa. Yield response factor (ky) for the silage maize for all growth season was 1.12

    A computational framework for complex disease stratification from multiple large-scale datasets.

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    BACKGROUND: Multilevel data integration is becoming a major area of research in systems biology. Within this area, multi-'omics datasets on complex diseases are becoming more readily available and there is a need to set standards and good practices for integrated analysis of biological, clinical and environmental data. We present a framework to plan and generate single and multi-'omics signatures of disease states. METHODS: The framework is divided into four major steps: dataset subsetting, feature filtering, 'omics-based clustering and biomarker identification. RESULTS: We illustrate the usefulness of this framework by identifying potential patient clusters based on integrated multi-'omics signatures in a publicly available ovarian cystadenocarcinoma dataset. The analysis generated a higher number of stable and clinically relevant clusters than previously reported, and enabled the generation of predictive models of patient outcomes. CONCLUSIONS: This framework will help health researchers plan and perform multi-'omics big data analyses to generate hypotheses and make sense of their rich, diverse and ever growing datasets, to enable implementation of translational P4 medicine

    E2F transcription factors and digestive system malignancies: How much do we know?

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    E2F family of transcription factors regulates various cellular functions related to cell cycle and apoptosis. Its individual members have traditionally been classified into activators and repressors, based on in vitro studies. However their contribution in human cancer is more complicated and difficult to predict. We review current knowledge on the expression of E2Fs in digestive system malignancies and its clinical implications for patient prognosis and treatment. E2F1, the most extensively studied member and the only one with prognostic value, exhibits a tumor-suppressing activity in esophageal, gastric and colorectal adenocarcinoma, and in hepatocellular carcinoma (HCC), whereas in pancreatic ductal adenocarcinoma and esophageal squamous cell carcinoma may function as a tumorpromoter. In the latter malignancies, E2F1 immunohistochemical expression has been correlated with higher tumor grade and worse patient survival, whereas in esophageal, gastric and colorectal adenocarcinomas is a marker of increased patient survival. E2F2 has only been studied in colorectal cancer, where its role is not considered significant. E2F4's role in colorectal, gastric and hepatic carcinogenesis is tumor-promoting. E2F8 is strongly upregulated in human HCC, thus possibly contributing to hepatocarcinogenesis. Adenoviral transfer of E2F as gene therapy to sensitize pancreatic cancer cells for chemotherapeutic agents has been used in experimental studies. Other therapeutic strategies are yet to be developed, but it appears that targeted approaches using E2F-agonists or antagonists should take into account the tissue-dependent function of each E2F member. Further understanding of E2Fs' contribution in cellular functions in vivo would help clarify their role in carcinogenesis. © 2013 Baishideng. All rights reserved

    E2F transcription factors and digestive system malignancies: How much do we know?

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    Citerne d'eau de pluie et effet sur le débit à l'exutoire du bassin versant de l'Orneau dans la région de Gembloux (Belgique)

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    Rainwater storage and effect on flow rate at watershed outflow. This study participates to the quantitative balance of rain water domestic use. It aims towards an optimal design of rain barrels volume, the feasibility of soil infiltration techniques with excess of water and the impact assessment of rain barrel on the decrease of peak flow in a pilot rural watershed of 9 km², considering the chronology of precipitation events. The parameters that are considered are the roofs area, the number of inhabitants in the house, the average daily rainfall water consumption, and the local pluviometry. In order to design the infiltration structure associated with the rain barrel, the volume of rainfall excess from the rain barrel needs to be evaluated. Afterwards, the infiltration structure may be dimensioned according to the soil infiltration characteristics. We assume that 75 l, out of the 115 l daily consumed by each inhabitant, are coming from the rain barrel and the remainder (40 l) is drawn from the drinking water distribution network. Calculations are carried out for roofs of 100, 135, 170 and 200 m², for a consumption of water ranging between 150 and 1,150 l per day per house and for rain barrels of 5, 10 and 20 m³. It appears that if correctly designed private rain barrel allows an opportune water use in households, the effect on flood reduction is, however, limited considering the relative low importance of the collecting surface (1.3% of the watershed surface)

    Concepts d'efficience et de productivité de l'eau (synthèse bibliographique)

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    Water efficiency and productivity concepts. A review. Water efficiency and productivity indicators are used in many scientific disciplines, usually to account for water losses that occur during its use, or products generated per unit of water consumed. The interpretation of these indicators is very diverse in the literature. However, the majority of definitions consider water efficiency as a measure of the effectiveness of irrigation, and view water productivity as a measure of the effectiveness of the physiological processes of both biomass production and crop yield formation, linked to the actual consumption of water by the crops. Thus, the consensus seems to be for water application efficiency (Ea) to be considered as the ratio of actual evapotranspiration to the water applied and productivity as the ratio of yield to actual evapotranspiration. The point of divergence relates fundamentally to the understanding of the constituent expressions of productivity (PE, product/"water consumed") and efficiency of water application (Ea, "water consumed"/"applied water"). Indeed, the term "water consumed" is referred to variously by several authors as "actual evapotranspiration", "gross irrigation plus rainfall", "evapotranspiration plus water lost at the plot but beneficial to other users", etc. Furthermore, while providing more details on the concepts of efficiency and water productivity, this review shows that the factors affecting these indicators have not yet been sufficiently elucidated. Thus, one of the axes of investigation could be to model the application efficiency of water firstly, according to water management practices and secondly, in terms of productivity levels in relation to the crop establishment period
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