Fuentes y preservación de materia orgánica en sedimentos recientes del estuario del río Yangtze, China

The vertical distributions of bulk and molecular biomarker compositions in the samples from four sediment cores of the Changjiang (Yangtze River) Estuary were determined. The changes in the bulk and molecular compositions with depth suggest that there have been recent changes in the marine autogenic and terrigenous supply. In the site at the boundary of the turbidity maximum (Site 8) and the most southern site (Site 26), the autogenic and allochthonous inputs make almost the same contribution to sedimentary organic matter. In the site close to the river mouth (Site 11), the organic matter mainly comes from the terrestrial input carried by the Changjiang water, whereas, in the most eastern site (Site 17), the organic matter consists of a mixture of recent and ancient Changjiang delta sedimentary residues. Significant downcore fluctuations were observed in the patterns of the bulk and molecular compositions, as well as in several biomarker ratios, which also indicates the different anoxic conditions at different depths of the core besides the source variation. In addition, the distributions of molecular compounds show that the organic matter is a mixture of immature and mature in the sediments of the four cores, which further indicates that the microbial activity is active in anoxic conditions, especially in the surface sediment. The vertical distributions of molecular compounds also show that the autogenic marine organic matter is more easily degraded, and that the molecular compounds evolve from unstable steric configurations to stable ones in the early diagenetic processes.Este artículo analiza la distribución vertical de la composición mayoritaria y de biomarcadores moleculares en muestras de sedimentos de cuatro testigos obtenidos en el estuario del río Yangtze. Los cambios de composición en profundidad sugieren variaciones recientes de los aportes autógenos y terrígenos. En el máximo de turbidez y en sus limites (estación 8) y en la estación más al sur (estación 26), los aportes autógenos y alóctonos tienen casi la misma contribución a la materia orgánica sedimentaria. En la estación próxima a la desembocadura (estación 11), la materia orgánica procede principalmente de los aportes terrestres del río Yangtze, mientras que en la estación situada mas al Este (estación 17), la materia orgánica consiste en una mezcla de aportes recientes del río Yangtze y de residuos sedimentarios de un antiguo delta del mismo río. Fluctuaciones significantes de la composición mayoritaria y molecular, así como de biomarcadores, fueron observadas a lo largo de los testigos, lo cual indica también condiciones de anoxia diferentes a distintas profundidades, aparte de las diferencias en la procedencia de los sedimentos. Además, la distribución de compuestos moleculares muestra que la materia orgánica es una mezcla de sedimentos maduros e inmaduros en los cuatro testigos, lo cual indica que la actividad microbiana es activa en condiciones de anoxia, especialmente en los sedimentos superficiales. La distribución vertical de los compuestos moleculares también muestra que la materia orgánica marina autógena es más fácilmente degradable, y que los compuestos moleculares evolucionan desde configuraciones inestables estéricas a configuraciones estables en las primeras fases de la diagénesis

Cost-effectiveness of policy options for sustainable wetland conservation : a case study of Qixinghe Wetland, China

The study aims to assist policy makers in deciding how best to balance economic development with wetland conservation. Agriculture accounts for more than 75% of the total water use in the Qixinghe Wetlands area. As the flow of water entering the wetlands is diverted, its ecosystem is damaged. This problem affects many wetland areas in China. Research evidence supports recommendations to local government to reconstruct the irrigation system in the area surrounding the Qixinghe Wetlands. These wetlands are the most important breeding ground and migration route for waterfowls in Northeastern Asia

Preservation of Simmental bull sperm at 0°C in Tris dilution: effect of dilution ratio and long-distance transport

Objective This study aimed to assess the impact of the dilution ratio of Tris diluent, storage at 0°C, and long-distance transportation on the spermatozoa of Simmental cattle. It also validated the feasibility of the regional distribution of fresh semen. Methods In experiment 1, semen was diluted at four dilution ratios (1:6, 1:9, 1:12, and 1:15) to determine the optimal dilution ratio of Tris diluent. In experiment 2, we assessed sperm viability, progressive motility (objectively assessed by computer-assisted sperm analyzer), and acrosome intactness in Tris dilutions kept at constant 0°C for 1, 3, 6, 9, and 12 days. We compared them to Tianshan livestock dilutions (Commercial diluent). In experiment 3, semen was diluted using Tris diluent, and sperm quality was measured before and after long-distance transport. Artificial insemination of 177 Simmental heifers compared to 156 using Tianshan Livestock dilution. Results The outcomes demonstrated that 1:9 was the ideal Tris diluent dilution ratio. The sperm viability, Progressive Motility, and acrosome integrity of both Tris and Tianshan dilutions preserved at 0°C gradually decreased over time. sperm viability was above 50% for both dilutions on d 9, with a flat rate of decline. The decrease in acrosome integrity rate was faster for Tianshan livestock dilutions than for Tris dilutions when stored at 0°C for 1 to 6 days. There was no significant difference (p>0.05) in sperm viability between semen preserved in Tris diluent after long-distance transportation and semen preserved in resting condition. The conception rates for Tris dilution and Tianshan livestock dilution were 49.15% and 46.15% respectively, with no significant difference (p>0.05). Conclusion This shows that Tris diluent is a good long-term protectant. It has been observed that fresh semen can be successfully preserved for long-distance transport when stored under 0°C conditions. Additionally, it is feasible to distribute semen regionally

Cost-Effectiveness of Policy Options for Sustainable Wetland Conservation: A Case Study of Qixinghe Wetland, China

This study assesses a number of potential policy options that could help protect the Qixinghe Wetlands which lie in the country's Sanjiang Plain. The region's wetlands are the most important breeding ground and migration route for waterfowls in Northeastern Asia, and provide a habitat for numerous species of wildlife. They face many challenges, one of the most significant being the disruption of the water supplies that feed them. Agriculture is the main cause of this problem, accounting for more than 75% of the total water use in the area. As the flow of water entering the wetlands is diverted, its ecosystem is damaged. This problem affects many wetland areas in China. The study is the work of a team of researchers from Renmin University of China, led by Wu Jian. It assesses the best way to reduce the conflict between wetland water needs and off-site water use. Its overall aim is to help policy makers decide how best to balance economic development with wetland conservation. The study recommends that the local government should reconstruct the irrigation system in the area surrounding the Qixinghe Wetlands as soon as possible. At the same time, training on water saving practices should be promoted amongst farmers. The study also suggests how these two key policies could be supported by improvements in conservation funding and management.wetland, China

Securing Water for Wetland Conservation in China - An Assessment of Policy Options

Wetlands are one of the world's most ecologically important and productive ecosystems. They face many challenges, one of the most sifnificant being the disruption of the water supplies that feed them. As the flow of water entering a wetland is diverted to other uses, the werland's ecosystme is damaged. This problem affects many wetland areas in China. This study assesses the situation in the Qixinghe Wetlands which lie in the country's Sanjiang Plain. The study hifhlights two policy options that could help improve the water supply to this important wetland area and suggests how these policies could be supported by improvements in funding and institutional support.wetland conservation, China

TL1A promotes metastasis and EMT process of colorectal cancer

Background: Metastasis is the major problem of colorectal cancer (CRC) and is correlated with the high mortality. Tumor necrosis factor-like cytokine 1A (TL1A) is a novel regulatory factor for inflammatory diseases. This work aimed to investigate the role of TL1A in CRC metastasis. Method: AOM/DSS-induced mouse model, xenograft tumor model and metastasis murine model were established to mimic the colitis-associated CRC and investigate CRC growth and metastasis in vivo. Colon tissues were assessed by hematoxylin/eosin (HE) staining and immunohistochemistry (IHC). CRC cell metastasis in vivo was observed using in vivo imaging system (IVIS). Cell viability and proliferation were examined using cell counting kit 8 (CCK-8) and EdU experiments. The expression of tumor growth factor β (TGFβ) and metastatic biomarkers were detected using western blotting experiment. The in vitro cell metastasis was measured by Transwell. Results: Knockdown of TL1A notably suppressed the generation of colonic tumors in azoxymethane/dextran sodium sulfate (AOM/DSS) model, suppressed in vivo CRC cell growth, as well as lung and liver metastasis. The inflammation response and inflammatory cell infiltration in tumor sites were decreased by TL1A depletion. The in vitro CRC cell growth and metastasis was also suppressed by shTL1A, along with altered expression of epithelial mesenchymal transition (EMT) biomarkers. TL1A depletion suppressed the level of the TGF-β1 receptor (TβRI) and phosphorylation of Smad3 in CRC cells. Stimulation with TGF-β recovered the CRC cell migration and invasion that suppressed by shTL1A. Conclusion: Our work implicated TL1A as a promoter of CRC generation and metastasis and defines TGF-β/Smad3 signaling as mediator of TL1A-regualated CRC cell metastasis

Anopheles gambiae densovirus (AgDNV) has negligible effects on adult survival and transcriptome of its mosquito host

Mosquito densoviruses (DNVs) are candidate agents for paratransgenic control of malaria and other vector-borne diseases. Unlike other mosquito DNVs, the Anopheles gambiae DNV (AgDNV) is non-pathogenic to larval mosquitoes. However, the cost of infection upon adults and the molecular mechanisms underpinning infection in the mosquito host are unknown. Using life table analysis, we show that AgDNV infection has minimal effects on An. gambiae survival (no significant effect in 2 replicates and a slight 2 day survival decrease in the third replicate). Using microarrays, we show that AgDNV has very minimal effect on the adult mosquito transcriptome, with only 4–15 genes differentially regulated depending on the statistical criteria imposed. The minimal impact upon global transcription provides some mechanistic understanding of lack of virus pathogenicity, suggesting a long co-evolutionary history that has shifted towards avirulence. From an applied standpoint, lack of strong induced fitness costs makes AgDNV an attractive agent for paratransgenic malaria control

Effect of different culture systems and 3, 5, 3'-triiodothyronine/follicle-stimulating hormone on preantral follicle development in mice.

The mechanical method to isolate preantral follicle has been reported for many years. However, the culture systems in vitro are still unstable. The aim of this study was to analyze the effect of the culture system of mice preantral follicles on the follicular development in vitro. The results showed that the 96-well plate system was the most effective method for mice follicle development in vitro (volume change: 51.71%; survival rate: 89%, at day 4). Follicle-stimulating hormone (FSH) and Thyroid hormone (TH) are important for normal follicular development and dysregulation of hormones are related with impaired follicular development. To determine the effect of hormone on preantral follicular development, we cultured follicle with hormones in the 96-well plate culture system and found that FSH significantly increased preantral follicular growth on day 4. The FSH-induced growth action was markedly enhanced by T₃ although T₃ was ineffective alone. We also demonstrated by QRT-PCR that T₃ significantly enhanced FSH-induced up-regulation of Xiap mRNA level. Meanwhile, Bad, cell death inducer, was markedly down-regulated by the combination of hormones. Moreover, QRT-PCR results were also consistent with protein regulation which detected by Western Blotting analysis. Taken together, the findings of the present study demonstrate that 96-well plate system is an effective method for preantral follicle development in vitro. Moreover, these results provide insights on the role of thyroid hormone in increasing FSH-induced preantral follicular development, which mediated by up-regulating Xiap and down-regulating Bad

Tool Wear and Surface Integrity of γ-TiAl Cryogenic Coolant Machining at Various Cutting Speed Levels

High-speed machining of γ-TiAl alloy is a significant challenge due to high cutting temperatures. From the perspective of environmental protection and improving tool life, appropriate cooling strategies should be adopted. Compared with dry and conventional flood cooling conditions, the feasibility of machining γ-TiAl in cryogenic LN2 cooling conditions was discussed. The cutting force, tool wear and its mechanism, and surface roughness, as well as sub-surface morphology characteristics, were studied by combining macro and micro techniques. The results revealed that the wear morphology of the rake and flank face under the three cooling media shows different degrees. The crater wear of the rake face is expanded at high speeds and then progresses into more serve flaking and notching wear. The main wear pattern on the flank face is gradually transformed from adhesive wear to diffusion and oxidation wear at high speeds in dry machining. In the LN2 condition, the diffusion of workpiece elements and cutting-edge oxidation were restrained. The wear pattern is still mainly adhesive wear. In addition, cryogenic machining shows significant advantages in reducing cutting force, suppressing heat-affected zone, improving surface quality, and inhibiting micro-lamellar deformation