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Soil and water conservation measures including terracing, afforestation, construction of sediment-trapping dams, and the 'Grain for Green Program' have been extensively implemented in the Yanhe River watershed, of the Loess Plateau, China, over the last six decades, and have resulted in large-scale land use and land cover changes. This study examined the trends and shifts in streamflow regime over the period of 1953-2010 and relates them to changes in land use and soil and water conservation and to the climatic factors of precipitation and air temperature. The non-parametric Mann-Kendall test and the Pettitt test were used to identify trends and shifts in streamflow and base flow. A method based on precipitation and potential evaporation was used to evaluate the impacts of climate variability and changes in non-climate factors changes on annual streamflow. A significant decrease ( p = 0.01) in annual streamflow was observed related to a significant change point in 1996, mostly because of significant decreases in streamflow ( p = 0.01) in the July to September periods in subsequent years. The annual base flow showed no significant trend from 1953 to 2010 and no change point year, mostly because there were no significant seasonal trends, except for significant decreases ( p = 0.05) in the July to September periods. There was no significant trend for precipitation over the studied time period, and no change point was detected. The air temperature showed a significant increasing trend ( p < 0.01), and 1986 ( p < 0.01) was the change point year. The climate variability, as measured by precipitation and temperature, and non-climate factors including land use changes and soil and water conservation were estimated to have contributed almost equally to the reduction in annual streamflow. Soil and water conservation practices, including biological measures (e.g. revegetation, planting trees and grass) and engineering measures (such as fish-scale pits, horizontal trenches, and sediment-trapping dams) play an important role in reduction of the conversion of rainfall to run-off. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The basidiomycetous yeast Rhodosporidium toruloides represents an excellent producer for microbial lipids and carotenoids. However, further rational engineering of this unconventional yeast remains challenging partially because of the absence of efficient and reliable transformation method. In this study, we developed an Agrobacterium-mediated transformation ( ATMT) protocol for effective gene integration into the R. toruloides genome. Both haploid and diploid strains were successfully modified, and the integration was confirmed by colony PCR, Western blot analysis and genome walking. We further demonstrated that multiple genes could be integrated by consecutive ATMT, leading to engineered strains simultaneously resistant to multiple antibiotics. Our results provided a practical method for functional integration and expression of exogenous genes in R. toruloides, which should facilitate the development of genetic tools and the construction of superior strains to produce biofuel molecules and biochemicals. [ABSTRACT FROM AUTHOR]

A method for the determination of 10 pyrethroid pesticide residues in tea was established by multi-plug filtration cleanup (m-PFC) method combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). Different extraction solvents (acetonitrile, acetone and ethyl acetate) and extraction methods (immersion without water and immersion with water) were compared. The effect of two kinds of QuEChERS pipes and m-PFC column on the purification of tea extracts and the pesticide recoveries were compared. The results showed that the tea samples could be extracted most efficiently when using acetonitrile without immersion in water. The m-PFC column had a good purification effect on the tea extract and could guarantee a high recovery rate. Good linear relationships were observed for the 10 pyrethroid pesticides, and the correlation coefficients ( R 2 ) were greater than0.9980. The average recoveries for the 10 pyrethroid pesticides were in the range of 87.5%-111.3% at four spiked levels, and the RSDs were in the range of 2.1%-8.9%. The LODs and LOQs were 0.001-0.015 mg/kg and 0.003-0.05 mg/kg, respectively. The method was applied to the determination of the 10 pyrethroid pesticides in 50 tea samples. The detection rate of the pyrethroid pesticides was 48%, but all the pesticide residues were below the national standard limits. Compared with the traditional QuEChERS and solid phase extraction methods, this method has the advantages of operational simplicity as well as high accuracy and good precision. The establishment of this method provides a new strategy for the rapid detection of pyrethroid pesticide residues in tea.

A method for the determination of 50 pesticides in fruits by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. The three QuEChERS methods (the original one without buffer, the one with acetate buffer and the one with citrate buffer) were compared. The purification effects of primary secondary amine (PSA) and SinChERS-Nano column were also investigated. The results showed that the acetate buffer and the citrate buffer had positive influence on the extraction compared to the original method without buffer, and there was no significant difference between the two methods using buffers. Finally, the QuEChERS method using acetate buffer was chosen as the extraction method. By comparing the purification effect images and the total ion current (TIC) chromatograms, SinChERS-Nano column was revealed to have a better cleaning effect, and was chosen for cleanup. The recoveries of methamidophos, acephate, omethoate, chlorothalonil and dicofol were in ranged of 71.2%-129.2%, the other 45 pesticides were ranged from 79.1% to 122.3%. The limits of detection (LODs) were 0.3-3.0 μ g/kg and the limits of quantification (LOQs) were 1.0-10.0 μ g/kg. The method is rapid and suitable for the screening of the 50 pesticide residues in citrus, grapes and other fruit samples.

Objectives: To establish a recombinase flippase (FLP) and flippase recognition target (FRT) system-mediated protocol for post-integration excision of exogenous DNA fragments in the oleaginous yeast Rhodosporidium toruloides., Results: Binary vectors were constructed to harbor FLP expressing cassette together with the hygromycin-resistance marker. Results showed that R. toruloides transformants produced FLP, but failed to mediate removal of the bleomycin-resistance marker within two FRT sites. When FLP was fused with a native nuclear localization signal (NLS) peptide, the system was found functional. Moreover, R. toruloides recombinant strains expressing the NLS-fused FLP under the control of PADH2, an promoter of alcohol dehydrogenase 2 gene (RHTO&#95;03062), were obtained to realize homologous recombination upon growing in glucose-deficient medium., Conclusions: We have devised a homologous recombination method for R. toruloides based on the FLP/FRT system, which may facilitate further metabolic engineering and designing advanced cell factories for value-added chemicals.

Objectives: To target a carotenoid biosynthetic gene in the oleaginous yeast Rhodosporidium toruloides by using the Agrobacterium-mediated transformation (AMT) method., Results: The RHTO&#95;04602 locus of R. toruloides NP11, previously assigned to code the carotenoid biosynthetic gene CRTI, was amplified from genomic DNA and cloned into the binary plasmid pZPK-mcs, resulting in pZPK-CRT. A HYG-expression cassette was inserted into the CRTI sequence of pZPK-CRT by utilizing the restriction-free clone strategy. The resulted plasmid was used to transform R. toruloides cells according to the AMT method, leading to a few white transformants. Sequencing analysis of those transformants confirmed homologous recombination and insertional inactivation of CRTI. When the white variants were transformed with a CRTI-expression cassette, cells became red and produced carotenoids as did the wild-type strain NP11., Conclusions: Successful homologous targeting of the CrtI locus confirmed the function of RHTO&#95;04602 in carotenoids biosynthesis in R. toruloides. It provided valuable information for metabolic engineering of this non-model yeast species.

Under nutrient-limited conditions, the red yeast Rhodosporidium toruloides can accumulate neutral lipids, of which the compositional fatty acids are mainly saturated and mono-unsaturated ones with 16 or 18 carbon atoms. To improve the linoleic acid content in the lipids, we enabled galactose-inducible expression of the gene encoding Δ12-fatty acid desaturase (FADS) from Mortierella alpina or Fusarium verticillioides by integration of the corresponding expression cassettes into the genome of R. toruloides haploid and diploid strains. The relative linoleic acid content increased up to fivefold and the final linoleic acid titer reached 1.3 g/L under flask culture conditions. Our results suggested that R. toruloides may be further explored as cell factory for production of high-valued lipids and other fatty acid derivatives as bio-based chemicals and fuels.

Background: Prostate stem/progenitor cells function in glandular development and maintenance. They may be targets for tumor initiation, so characterization of these cells may have therapeutic implications. Cells from dissociated tissues that form spheres in vitro often represent stem/progenitor cells. A subset of human prostate cells that form prostaspheres were evaluated for self-renewal and tissue regeneration capability in the present study., Methods: Prostaspheres were generated from 59 prostatectomy specimens. Lineage marker expression and TMPRSS-ERG status was determined via immunohistochemistry and fluorescence in situ hybridization (FISH). Subpopulations of prostate epithelial cells were isolated by cell sorting and interrogated for sphere-forming activity. Tissue regeneration potential was assessed by combining sphere-forming cells with rat urogenital sinus mesenchyme (rUGSM) subcutaneously in immunocompromised mice., Results: Prostate tissue specimens were heterogeneous, containing both benign and malignant (Gleason 3-5) glands. TMPRSS-ERG fusion was found in approximately 70% of cancers examined. Prostaspheres developed from single cells at a variable rate (0.5-4%) and could be serially passaged. A basal phenotype (CD44+CD49f+CK5+p63+CK8-AR-PSA-) was observed among sphere-forming cells. Subpopulations of prostate cells expressing tumor-associated calcium signal transducer 2 (Trop2), CD44, and CD49f preferentially formed spheres. In vivo implantation of sphere-forming cells and rUGSM regenerated tubular structures containing discreet basal and luminal layers. The TMPRSS-ERG fusion was absent in prostaspheres derived from fusion-positive tumor tissue, suggesting a survival/growth advantage of benign prostate epithelial cells., Conclusion: Human prostate sphere-forming cells self-renew, have tissue regeneration capability, and represent a subpopulation of basal cells., ((c) 2009 Wiley-Liss, Inc.)