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Lead (Pb), a highly toxic metal ion, is detrimental to plants and humans. Existing botanical techniques for Pbcontaminated soil remediation are limited in their efficiency. Here, we investigated the use of the fungus Trichoderma asperellum Samuels, Lieckf&Nirenberg SD-5, which we identified previously as being Pb-resistant, for phytoremediation and for its effects on plant growth, Pb adsorption, and physiological responses in perennial ryegrass (Lolium perenne L. 'Lark'). We set up four soil treatments: CK (uncontaminated by Pb), T1 (1000 mg kg-1 Pb), T2 (1:9 ratio of sawdust to T1), and T3 (T2 inoculated with T. asperellum SD-5). A pot experiment revealed that the addition of the Pb-resistant microorganism promoted growth and increased biomass in ryegrass under Pb stress, in addition to significantly enhancing photosynthesis by increasing the leaf chlorophyll content and improving the total protein content and expression of the pAPX, POD, SOD, and GPX genes, evidence of an improved antioxidant system and the alleviation of Pb stress. We demonstrated that Pb-resistant microorganisms can enhance Pb extraction from the soil, thus improving remediation. Mitigation mechanisms operating at the physiological and gene expression levels were also determined, providing a scientific basis for the role of combined plant-microorganism methods in remediating Pb-contaminated soil. [ABSTRACT FROM AUTHOR]

The practice of split households among rural - urban migrants in China has persisted for more than twenty years. In this paper we compare three forms of split households, differentiated by whether the migrant's spouse and children are left behind or have joined the migrant: sole migration, couple migration, and family migration. Our survey of fifty chengzhongcun (urban villages) in Beijing conducted in 2008 shows that couple migration and family migration are outcomes of rural Chinese actively rearranging their household division of labor in order to maximize earnings from urban work opportunities. Migrants' decision to leave the children behind or to bring them along depends on the children's age and whether migrants' parents are available to help. Contrary to expectation, more household members in the city signals neither stronger intention to stay nor greater trust in the host society. These findings highlight the importance of thinking about migrants as circulators and thinking about migration, including family migration, as not necessarily a prelude to permanent settlement. They also underscore the need to address the experiences of long-term split households, a discourse that has received much less attention than one that assumes that a family lives together most of the time. [ABSTRACT FROM AUTHOR]

The article presents a study which offers updated information on the changes and level of regional inequality in China from 1978-2006. It also focuses on revealing the spatial dynamics of inequality by identifying the provinces and regions whose growth trajectories have influenced the level of regional inequality in the country. The study demonstrates the decline in interprovincial inequality in China during the 1980s and 1990s. The countervailing patterns in the interregional and intraregional inequalities are also discussed.

Foxtail millet (Setaria italica (L.) Beauv.) is an economically and nutritionally important crop grown primarily in Asian countries. However, optimal NPK fertilizer application rates and ratios have not been established for foxtail millet cultivation. In this study, a two years field experiment was conducted in typical warm-temperate sub-humid continental monsoon climate of brown soil, aimed to establish a rational nitrogen:phosphorus: potassium (N:P:K) ratio to improve foxtail millet production. Four N (0, 112.5, 225.0, and 337.5 kg ha-1), four P (0, 45.0, 90.0, and 135.0 kg ha-1), and four K (0, 75.0, 150.0, and 225.0 kg ha-1) fertilization rates were employed in fourteen different treatments. Crop yield, agronomic characteristics, and nutrient enrichment were evaluated. Crop yield was significantly influenced by the N:P:K ratio. The highest crop yield (3927.0 kg ha-1) was achieved with 112.5 kg ha-1 N, 90.0 kg ha-1 P, and 150.0 kg ha-1 K treatment. It was 68.8% higher than the control. The optimal N, P, and K application rates were 130.4-173.5, 83.5-103.8, and 133.4-153.2 kg ha-1, respectively. Crop yield was positively correlated with plant height, leaf length and width, kernel P and K, and chlorophyll. Rational fertilization improves foxtail millet yield and may be applied for the improvement of crop productivity and the mitigation of agricultural pollution. [ABSTRACT FROM AUTHOR]

The preparation, in-vitro release, in-vitro cytotoxicity, and in-vivo drug delivery of doxorubicin (DOX)-loaded chitosan (CS)-poly(acrylic acid) (PAA) hollow nanospheres were investigated. The loading was done by dissolving a certain amount of DOX in non-cross-linked CS-PAA nanospheres aqueous solution followed by cross-linking chitosan with glutaraldehyde. The drug-loading content was up to 4.3% and the size of drug-loaded hollow nanospheres, determined by dynamic light scattering, was 118 nm. The nanospheres showed a continuous release of the entrapped DOX up to 10 days in vitro and showed comparable in-vitro cytotoxicity against HepG2 cells compared to the free DOX. In-vivo DOX delivery of DOX-loaded CS-PAA nanospheres showed that DOX concentration in blood can be maintained for a longer period than free DOX solution, and the DOX concentration in mice liver can be maintained constantly at relatively high level. The interesting feature of DOX-loaded CS-PAA hollow nanopspheres is that the loaded DOX can be delivered into the mice brain. The confocal laser scanning microscopy analysis reveals that fluorescein isothiocyanate (FITC)-labeled CS-PAA can deposit in different organs including liver, spleen, and brain. [ABSTRACT FROM AUTHOR]