ALBERT

Description: Spatial heterogeneity of soil has great impacts on dynamic processes of the hydrological systems. However, it is challenging and expensive to obtain spatial distribution of soil hydraulic properties, which often requires extensive soil sampling and observations and intensive laboratory analyses, especially in high elevation, hard to access mountainous areas. This study evaluates the impacts of soil heterogeneity on hydrological process in a high elevation, topographically complex watershed in Northwest China. Two approaches were used to derive the spatial heterogeneity of soil properties in the study watershed: 1) The spatial clustering method, Full-Order-CLK was used to determine five soil heterogeneous clusters (Configurations 97, 80, 65, 40, and 20) through large number of soil sampling and in situ observations; and 2) The average values of soil hydraulic properties for each soil type were derived from the coarse provincial soil datasets (Gansu Soil Handbook at 1:1, 000, 000 scale). Subsequently, SWAT model was used to quantify the impact of the spatial heterogeneity of soil hydraulic properties on hydrological process in the study watershed. Results show the simulations by SWAT with the spatially clustered soil hydraulic information from the field sampling data had much better representation of the soil heterogeneity and more accurate performance than the model using the average soil property values for each soil type derived from the coarse soil datasets. Thus, incorporating detailed field sampling soil heterogeneity data greatly improves performance in hydrological modeling. This article is protected by copyright. All rights reserved.

Description: To improve the ablation resistance of PIP-C/ SiC composites, zirconium carbide ( ZrC )-modified SiC coating was prepared by chemical vapor deposition combined with slurry painting, then the ablation capability of the coated composites was tested under an oxy-acetylene torch. Compared with the uncoated composites, linear and mass ablation rates of the coated composites decreased by 73.6% and 76.4%, respectively. The formation of zirconia from the oxidation of ZrC improved the ablation resistance of the composites because of anti-oxidation performance, which absorbed heat from the flame and reduced erosive attack to C / SiC composites. Zirconia also acted as an accelerator for carbon fiber oxidation as it reacted with carbon during ablation. The heterogeneous reactions controlled the ablation of the composites.

Description: A chiral helical coordination polymer [Ag(pmta)] n ( 1 ) was prepared by the reaction of the asymmetric organic spacer 2-pyrimidylthioacetic acid (Hpmta) with silver(I) acetate. Complex 1 has a hetero-chiral coaxial helical structure, which is further extended into a 2D network structure by various supramolecular interactions. Furthermore, complex 1 exhibits strong fluorescence emission in the solid state and modest power second-harmonic-generation (SHG) efficiency at room temperature.

Description: Understanding the molecular mechanisms of flowering and maturity is important for improving the adaptability and yield of seed crops in different environments. In soybean, a facultative short-day plant, geneti...

Description: Shenzhen, as the first special economic zone in the world, has been in the process of rapid urbanization for 30 years. Many special economic zones have been established in China and other nations following Shenzhen's experience. However, Shenzhen has attained significant economic development with an attendant cost of environmental degradation, and similar results may be seen in other zones in the future. Here we use a pollution index method to evaluate the effect of such rapid urban development on the surface water quality in Shenzhen from 1991 to 2008. Rapid urbanization has affected surface water quality, but environmental policies can mitigate some of these effects, although such policy-induced improvements required some time before showing efficacy. As their use of special economic zones proliferates worldwide, greater consideration of the potential effects on water quality, and their overall sustainability, must receive greater attention.

Description: Scandium fluoride ( ScF 3 ) belongs to one of the rare compounds which exhibit isotropic negative thermal expansion. Here, a facile and environmentally friendly hydrothermal synthesis method has been presented. High-quality single-crystalline ScF 3 cubes, with an average size of 200 nm, can be easily fabricated in a large scale. Sc (NO 3 ) 3 and NH 4 HF 2 were used as precursors. The as-prepared ScF 3 demonstrates cubic symmetry ( Pm -3  m ), which was confirmed by X-ray diffraction and selected-area electron diffraction. Its uniform morphology and size were characterized by high-resolution transmission electron microscopy. Furthermore, thermal analysis was also performed in argon gas atmosphere to investigate its thermal stability.

Description: A chiral helical coordination polymer [Ag(pmta)] n ( 1 ) was prepared by the reaction of the asymmetric organic spacer 2-pyrimidylthioacetic acid (Hpmta) with silver(I) acetate. Complex 1 has a hetero-chiral coaxial helical structure, which is further extended into a 2D network structure by various supramolecular interactions. Furthermore, complex 1 exhibits strong fluorescence emission in the solid state and modest power second-harmonic-generation (SHG) efficiency at room temperature.

Description: Background: Plants have developed a variety of mechanisms to counteract aphid attacks. They activate their defences by changing the expression of specific genes. Previously we identified an activation tag mutant of Arabidopsis thaliana on which Myzus persicae population development was reduced. Activation tag mutants are gain-of-function in which the expression of a gene is increased by the insertion of the Cauliflower mosaic virus 35S enhancer that acts on the natural promoter. By further characterizing this previously identified mutant we identified a gene that reduces performance of M. persicae and also provided clues about the mechanism involved. Results: We show that SKU5 SIMILAR 13 (SKS13), a gene whose expression in wild type plants is restricted to pollen and non-responsive to M. persicae attack, is overexpressed in the A. thaliana mutant showing reduced performance of M. persicae. Monitoring M. persicae feeding behaviour on SKS13 overexpressing plants indicated that M. persicae have difficulties feeding from the phloem. The constitutive expression of SKS13 results in accumulation of reactive oxygen species, which is possibly regulated through the jasmonic acid pathway. The enhanced resistance is not aphid species specific as also the population development of Brevicoryne brassicae was affected. Conclusions: We demonstrate that constitutive expression in leaves of the pollen-specific gene SKS13 can enhance plant defence, resulting in a reduction of M. persicae population development and also decreases the transmission of persistent viruses. Overexpression of SKS13 in A. thaliana also affects B. brassicae and possibly other phloem feeding insects as well. Identifying genes that can enhance plant defence against insects will be important to open up new avenues for the development of insect resistant crop plants.

Description: Background: The CYP7A1 gene polymorphism has been reported to be associated with gallbladder stone disease (GSD) and serum lipid levels, but the results were inconsistent. This meta-analysis aimed to evaluate the influence of the -204A 〉 C polymorphism in the promoter of CYP7A1 gene on the GSD and serum lipid levels. Methods: According to inclusion/exclusion criteria, eligible studies on CYP7A1 gene -204A 〉 C polymorphism of serum lipid levels and the risk of GSD were retrieved. Depending on the between-study heterogeneity, the fixed- or random-effects model was applied, and the data were analyzed using the RevMan software (V5.2). Results: Five studies totaling 830 GSD patients and 882 healthy controls were used to evaluate the relation of CYP7A1 -204A 〉 C polymorphism with GSD. Overall comparison of alleles A with C in all study population yielded 5% but non-significant increased risk of GSD (OR = 1.05, 95% CI: 0.91--1.22, P = 0.48). Subgroup analysis by ethnic differences did not show any association between CYP7A1 -204A 〉 C polymorphism and GSD either. Four studies totaling 802 cases and 691 controls were used to assess the relation of CYP7A1 -204A 〉 C polymorphism with serum lipid levels. All the subjects were from the Asian population. The pooled effects indicated that AC genotype had higher levels of TG than AA (MD = -0.42, 95% CI: -0.76---0.08, P = 0.01). CC genotype in cases had higher levels of TC (MD = 0.65, 95% CI: 0.25--1.05, P = 0.001) and LDL-C (MD = 0.40, 95% CI: 0.06--0.73, P = 0.02) than AA, AA (MD = -0.35, 95% CI: -0.60---0.10, P = 0.007) and AC (MD = -0.35, 95% CI: -0.61---0.08, P = 0.01) genotypes in controls had higher levels of TC than CC, and AA genotype in controls had higher levels of HDL-C than CC (MD = -0.15, 95% CI: -0.21---0.09, P 〈 0.00001). Conclusions: The CYP7A1 -204A 〉 C polymorphism is significantly associated with serum lipid levels in Asian population, but not gallbladder stone disease.