25 research outputs found

    Genomic prediction accounting for genotype by environment interaction offers an effective framework for breeding simultaneously for adaptation to an abiotic stress and performance under normal cropping conditions in rice

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    Developing rice varieties adapted to alternate wetting and drying water management is crucial for the sustainability of irrigated rice cropping systems. Here we report the first study exploring the feasibility of breeding rice for adaptation to alternate wetting and drying using genomic prediction methods that account for genotype by environment interactions. Two breeding populations (a reference panel of 284 accessions and a progeny population of 97 advanced lines) were evaluated under alternate wetting and drying and continuous flooding management systems. The predictive ability of genomic prediction for response variables (index of relative performance and the slope of the joint regression) and for multi-environment genomic prediction models were compared. For the three traits considered (days to flowering, panicle weight and nitrogen-balance index), significant genotype by environment interactions were observed in both populations. In cross validation, predictive ability for the index was on average lower (0.31) than that of the slope of the joint regression (0.64) whatever the trait considered. Similar results were found for progeny validation. Both cross-validation and progeny validation experiments showed that the performance of multi-environment models predicting unobserved phenotypes of untested entrees was similar to the performance of single environment models with differences in predictive ability ranging from -6–4% depending on the trait and on the statistical model concerned. The predictive ability of multi-environment models predicting unobserved phenotypes of entrees evaluated under both water management systems outperformed single environment models by an average of 30%. Practical implications for breeding rice for adaptation to alternate wetting and drying system are discussed

    Rice diversity panel provides accurate genomic predictions for complex traits in the progenies of biparental crosses involving members of the panel

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    So far, most potential applications of genomic prediction in plant improvement have been explored using cross validation approaches. This is the first empirical study to evaluate the accuracy of genomic prediction of the performances of progenies in a typical rice breeding program. Using a cross validation approach, we first analyzed the effects of marker selection and statistical methods on the accuracy of prediction of three different heritability traits in a reference population (RP) of 284 inbred accessions. Next, we investigated the size and the degree of relatedness with the progeny population (PP) of sub-sets of the RP that maximize the accuracy of prediction of phenotype across generations, i.e., for 97 F5–F7 lines derived from biparental crosses between 31 accessions of the RP. The extent of linkage disequilibrium was high (r2 = 0.2 at 0.80 Mb in RP and at 1.1 Mb in PP). Consequently, average marker density above one per 22 kb did not improve the accuracy of predictions in the RP. The accuracy of progeny prediction varied greatly depending on the composition of the training set, the trait, LD and minor allele frequency. The highest accuracy achieved for each trait exceeded 0.50 and was only slightly below the accuracy achieved by cross validation in the RP. Our results thus show that relatively high accuracy (0.41–0.54) can be achieved using only a rather small share of the RP, most related to the PP, as the training set. The practical implications of these results for rice breeding programs are discussed. (Résumé d'auteur

    AN EFFICIENT ARCHITECTURE VLSI FOR 4×4 INTRA PREDICTION IN HEVC STANDARD

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    International audienceThe HEVC is a proposal of new video coding standard that will be used for a wide range of applications like ULTRA HD and 3D applications. MPEG and VCEG have established a Joint Collaborative Team on Video Coding (JCT-VC) to develop the HEVC (High Efficiency Video Coding) standard which is expected to provide a significant improvement in data transmission and streaming efficiency compared to H.264. In this proposal standard, various modules of coding are defined. Among the most complex is the module of the intra prediction. The HEVC defines 35 modes of intra prediction for 8 × 8, 16 × 16, 32 × 32, 3 modes for 64 × 64 and 17 modes for 4 × 4 while the H.264/AVC (Advanced Video Coding) uses 9 modes for intra 4 × 4 and 4 modes for intra 16 × 16. In this paper, we propose an efficient uniform architecture for all of the 4 × 4 intra directional modes. This architecture offers an important gain in case of treatment time compared to the literature. Our proposed architecture is implemented with the technology TSMC 0.18μm CMO

    Three Component One-Pot Synthesis and Antiproliferative Activity of New [1,2,4]Triazolo[4,3-<i>a</i>]pyrimidines

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    A series of new [1,2,4]triazolo[4,3-a]pyrimidine derivatives was prepared using a one-pot three-component synthesis from 5-amino-1-phenyl-1H-1,2,4-triazoles, aromatic aldehydes and ethyl acetoacetate. The compound structures were confirmed by IR, 1H-NMR, 13C-NMR, HRMS and X-ray analyses. The biological activity of these compounds as antitumor agents was evaluated. Their antitumor activities against cancer cell lines (MDA-MB-231 and MCF-7) were tested by the MTT in vitro method. Among them, compounds 4c and 4j displayed the best antitumor activity with IC50 values of 17.83 μM and 19.73 μM against MDA-MB-231 and MCF-7 cell lines, respectively, compared to the Cisplatin reference

    Optimization of Hydrothermal and Diluted Acid Pretreatments of Tunisian Luffa cylindrica (L.) Fibers for 2G Bioethanol Production through the Cubic Central Composite Experimental Design CCD: Response Surface Methodology

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    This paper opens up a new issue dealing with Luffa cylindrica (LC) lignocellulosic biomass recovery in order to produce 2G bioethanol. LC fibers are composed of three principal fractions, namely, α-cellulose (45.80%  ± 1.3), hemicelluloses (20.76%  ± 0.3), and lignins (13.15%  ± 0.6). The optimization of LC fibers hydrothermal and diluted acid pretreatments duration and temperature were achieved through the cubic central composite experimental design CCD. The pretreatments optimization was monitored via the determination of reducing sugars. Then, the 2G bioethanol process feasibility was tested by means of three successive steps, namely, LC fibers hydrothermal pretreatment performed at 96°C during 54 minutes, enzymatic saccharification carried out by means of a commercial enzyme AP2, and the alcoholic fermentation fulfilled with Saccharomyces cerevisiae. LC fibers hydrothermal pretreatment liberated 33.55 g/kg of reducing sugars. Enzymatic hydrolysis allowed achieving 59.4 g/kg of reducing sugars. The conversion yield of reducing sugar to ethanol was 88.66%. After the distillation step, concentration of ethanol was 1.58% with a volumetric yield about 70%

    Supplemental material for Ben Hassen et al., 2018

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    <p> Two Supplementary figures and seven Supplementary tables. Detailed description of each figure and table is presented in the first page of the file.<br></p
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