To genetically dissect drought resistance associated with japonica upland rice, we evaluated a doubled haploid (DH) population from a cross between two japonica cultivars for seven root traits under three different growing conditions (upland, lowland and upland in PVC pipe). The traits included basal root thickness (BRT), total root number (RN), maximum root length (MRL), root fresh weight (RFW), root dry weight (RDW), ratio of root fresh weight to shoot fresh weight (RFW/SFW) and ratio of root dry weight to shoot dry weight (RDW/SDW). The BRT was significantly correlated with the index of drought resistance, which was defined as the ratio of yield under the stress of the upland condition to that under the normal lowland condition. A complete genetic linkage map with 165 molecular markers covering 1,535 cM was constructed. Seven additive quantitative trait loci (QTLs) and 15 pairs of epistatic loci for BRT and RN were identified under upland and lowland conditions, and 12 additive QTLs and 17 pairs of epistatic QTLs for BRT, RN, MRL, RFW, RFW/SFW and RDW/SDW were identified under the PVC pipe condition. Four additive QTLs and one pair of epistatic QTLs controlling IDR were also found. These QTLs individually explained up to 25.6% of the phenotypic variance. QTL x environment (Q x E) interactions were detected for all root traits, and the contributions of these interactions ranged from 1.1% to 19.9%. Five co-localized QTLs controlling RFW and RDW, RFW/SFW, RDW/SDW and IDR, BRT and RN, RN, MRL and IDR were found. Four types of QTLs governing BRT and RN were classified by their detection in the upland and lowland conditions. Some common QTLs for root traits across different backgrounds were also revealed. These co-localized QTLs and common QTLs will facilitate marker-assisted selection for root traits in rice breeding programs.

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Collaborative filtering (CF) recommenders based on User-Item rating matrix as explicitly obtained from end users have recently appeared promising in recommender systems. However, User-Item rating matrix is not always available or very sparse in some web applications, which has critical impact to the application of CF recommenders. In this article we aim to enhance the online recommender system by fusing virtual ratings as derived from user reviews. Specifically, taking into account of Chinese reviews' characteristics, we propose to fuse the self-supervised emotion-integrated sentiment classification results into CF recommenders, by which the User-Item Rating Matrix can be inferred by decomposing item reviews that users gave to the items. The main advantage of this approach is that it can extend CF recommenders to some web applications without user rating information. In the experiments, we have first identified the self-supervised sentiment classification's higher precision and recall by comparing it with traditional classification methods. Furthermore, the classification results, as behaving as virtual ratings, were incorporated into both user-based and item-based CF algorithms. We have also conducted an experiment to evaluate the proximity between the virtual and real ratings and clarified the effectiveness of the virtual ratings. The experimental results demonstrated the significant impact of virtual ratings on increasing system's recommendation accuracy in different data conditions (i.e., conditions with real ratings and without).

Magnesium (Mg)-deficiency is a widespread problem adversely affecting the quality and yield of crops, including citrus. 'Xuegan' [Citrus sinensis (L.) Osbeck] seedlings were irrigated every other day with nutrient solution at an Mg concentration of 0 mM (Mg-deficiency) or 1 mM (Mg-sufficiency) for 16 weeks. Thereafter, biomass, leaf mass per area, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), pigments in the upper and lower leaves, Mg, gas exchange, organic acids, nonstructural carbohydrates, total soluble proteins, amino acids, phenolics and anthocyanins, and key enzymes related to organic acid, amino acid and phenolic metabolisms in the roots, and upper and lower leaves were assayed in order to test the hypothesis that Mg-deficiency-induced alterations of gas exchange, major metabolites and key enzymes may differ among the roots, and upper and lower leaves. Magnesium-deficiency affected the most measured parameters more in the lower than in the upper leaves except for the nonstructural carbohydrates, but the variation trends were similar between the two. Despite increased accumulation of nonstructural carbohydrates, the lower CO2 assimilation in the Mg-deficient leaves was not caused by the feedback inhibition mechanism via sugar accumulation. Both dark respiration and organic acid metabolism were elevated in the Mg-deficient lower leaves to 'consume' the excess carbohydrates, and inhibited in the Mg-deficient roots with less accumulation of nonstructural carbohydrates to keep the balance of net carbon. More total phenolics and fewer anthocyanins were accumulated in the Mg-deficient lower leaves, whereas the accumulation of both total phenolics and anthocyanins was reduced in the Mg-deficient roots. Interestingly, amino acid biosynthesis was repressed in the Mg-deficient roots and lower leaves, thus lowering the level of total free amino acids in these roots and leaves. To conclude, great differences existed in the Mg-deficiency-induced alterations of gas exchange, major metabolites and key enzymes among the roots, and upper and lower leaves.

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Therefore, the LINE-1 promoter methylation might contribute to the risk of Pb poisoning and identified a possible epigenetic biomarker for Pb toxicity, especially in individuals occupationally exposed to Pb.

Figure 2. (a) CV curves of PT-2 NO 2 at 0.1 mV s À1 .(b) Galvanostatic discharge-chargecurves of PT-2 NO 2 and (c) cycling performanceo fd ifferent samples at 50 mA g À1 .(d) Rate capabilities of differents amples. (e) Galvanostatic discharge-charge curves of PT-2 NO 2 at different current densities. Figure 4. (a) Representativefirst discharge and charge profiles of PT-2 NO 2 at 50 mA g À1 and (b) correspondinge xs itu FTIRspectraa tmarkedp oints.E xs itu FTIR spectraof( c) PT and (d) PT-2 NO 2 during different discharge and charge processes.