Impact of Bt Cotton on the Farmer's Livelihood System in China

In order to analyze the impacts of Bt cotton on the farmers' livelihood system, we interviewed 169 farmers and extension personnel in the main cotton production areas in Hebei province in the year 2002 and 2003. An integrative method was used in which a multidisciplinary approach was employed including agronomy, economics and sociology. The results showed that the application of Bt cotton increased the cotton growing area as well as farmers' income. For 67% of the farmers interviewed, cotton area has been continuously increasing since 1997. The cotton net margin in one cropping cycle came out to be higher than the combined net margins of wheat and corn in two cropping cycles. The income from cotton played a significant role in the investment to education, leisure and health care. The socio-economic impacts of cotton production are nevertheless not yet optimal because there were still many factors limiting them. Lack of labor and land were the main limiting factors. Productivity is restrained by the high price of Bt cotton seeds which pushed farmers to keep seeds from their own cotton production (42% of the farmers in 2002 and 2003). Farmers are still lacking technical command in using Bt-cotton: 78% of the farmers admitted that while more than 94% of the farmers complained not getting information from local extension and technical services. More success in using Bt-cotton calls upon going beyond providing seeds and asks for continuous assistance from research and extension department, notably to achieve a full knowledge of the Bt-cotton characteristic so as to optimally integrate it into the farmers' system.China; Bt Cotton; biotechnologies; impact evaluation; Livelihood

Microbial-feeding interactions reveal the effects of feeding blood on the gut microbiota of the aquaculture leech (Hirudo nipponica)

Leeches (Hirudo nipponica), as a kind of aquatic animal, mainly feed on fresh blood. After feeding, they needed to digest for a long time because the intestinal digestive enzyme content is low, so their digestive needed the help of gut microbiota. Here, we examined intestinal microbiota in captive Hirudo nipponica of different periods after feeding blood with high-throughput sequencing. The results showed that gut microbial diversity was lower before feeding than after. At the level of the core phylum of the gut microbiota of Hirudo nipponica, the focus was on Proteobacteria, Bacteroidetes, and Firmicutes. After feeding blood, the relative abundance of Proteobacteria decreased, while the opposite was true for Bacteroidetes and Firmicutes. The core bacteria at the genus level are Aeromonas and Mucinivorans. The results show that the structure of the gut microbiota and function are closely associated with the blood feeding. The study aimed to lay a theoretical foundation for the blood-digestive mechanism of Hirudo nipponica

Expression Analysis of Four Peroxiredoxin Genes from Tamarix hispida in Response to Different Abiotic Stresses and Exogenous Abscisic Acid (ABA)

Peroxiredoxins (Prxs) are a recently discovered family of antioxidant enzymes that catalyze the reduction of peroxides and alkyl peroxides. In this study, four Prx genes (named as ThPrxII, ThPrxIIE, ThPrxIIF, and Th2CysPrx) were cloned from Tamarix hispida. Their expression profiles in response to stimulus of NaCl, NaHCO3, PEG, CdCl2 and abscisic acid (ABA) in roots, stems and leaves of T. hispida were investigated using real-time RT-PCR. The results showed that the four ThPrxs were all expressed in roots, stems and leaves. Furthermore, the transcript levels of ThPrxIIE and ThPrxII were the lowest and the highest, respectively, in all tissue types. All the ThPrx genes were induced by both NaCl and NaHCO3 and reached their highest expression levels at the onset of stress in roots. Under PEG and CdCl2 stress, the expression patterns of these ThPrxs showed temporal and spatial specificity. The expressions of the ThPrxs were all differentially regulated by ABA, indicating that they are all involved in the ABA signaling pathway. These findings reveal a complex regulation of Prxs that is dependent on the type of Prx, tissue, and the signaling molecule. The divergence of the stress-dependent transcriptional regulation of the ThPrx gene family in T. hispida may provide an essential basis for the elucidation of Prx function in future work

A Review of Cavitation Erosion on Pumps and Valves in Nuclear Power Plants

The cavitation erosion failure of pumps or valves induces the low efficiency and reduced service life of nuclear reactors. This paper reviews works regarding the cavitation erosion of pumps and valves in the nuclear power industry and academic research field. The cavitation erosion mechanisms of materials of pumps and valves are related to the microstructure and mechanical properties of the surface layer. The cavitation erosion resistance of austenitic stainless steel can be ten times higher than that of ferritic steel. The cavitation erosion of materials is related to the hardness, toughness, and martensitic transformation capacity. Erosion wear and erosion–corrosion research is also reviewed. Erosion wear is mainly influenced by the hardness of the material surface. Erosion–corrosion behavior is closely connected with the element composition. Measures for improving the cavitation erosion of pumps and valves are summarized in this paper. The cavitation erosion resistance of metallic materials can be enhanced by adding elements and coatings. Adhesion, inclusion content, and residual stress impact the cavitation erosion of materials with coatings

Cavitation Damage Prediction of Stainless Steels Using an Artificial Neural Network Approach

Cavitation damage has not been well predicted because of its complex relationship of many mechanical and microstructural factors. An artificial neural network approach of the back-propagation network was used to predict cavitation damage of stainless steels, 316L and 420, in terms of the significant influence of cavitation time, roughness, and residual stress on cavitation damage. Mean depth of erosion was used to quantitatively describe cavitation damage of 316L and 420. Prediction accuracy was improved by analyzing the effects of the number and type of input nodes, the number of nodes in the hidden layer, and different activation functions on prediction accuracy. The best performance was in the model with the input nodes of cavitation time and roughness, eleven nodes in the hidden layer, and the activation function of logsig

Impact of Bt Cotton on the Farmer’s Livelihood System in China

In order to analyze the impacts of Bt cotton on the farmers ’ livelihood system, we interviewed 169 farmers and extension personnel in the main cotton production areas in Hebei province in the year 2002 and 2003. An integrative method was used in which a multidisciplinary approach was employed including agronomy, economics and sociology. The results showed that the application of Bt cotton increased the cotton growing area as well as farmers' income. For 67 % of the farmers interviewed, cotton area has been continuously increasing since 1997. The cotton net margin in one cropping cycle came out to be higher than the combined net margins of wheat and corn in two cropping cycles. The income from cotton played a significant role in the investment to education, leisure and health care. The socio-economic impacts of cotton production are nevertheless not yet optimal because there were still many factors limiting them. Lack of labor and land were the main limiting factors. Productivity is restrained by the high price of Bt cotton seeds which pushed farmers to keep seeds from their own cotton production (42 % of the farmers in 2002 and 2003). Farmers are still lacking technical command in using Bt-cotton: 78 % of the farmers admitted that while more than 94 % of the farmers complained not getting information from local extension and technical services. More success in using Bt-cotton calls upon going beyond providing seeds and asks for continuous assistance from research and extension department, notably to achieve a full knowledge of the Bt-cotton characteristic so as to optimally integrate it into the farmers ’ system

Visual Prediction of Typhoon Clouds With Hierarchical Generative Adversarial Networks

We develop a hierarchical generative adversarial network (HGAN) for generating future typhoon cloud remote sensing images, which enables a visual means to typhoon cloud prediction. The HGAN consists of a global generator and a local discriminator. The global generator aims at producing the future typhoon cloud images as realistic as possible and accordingly reveals the structure and future location of the typhoon clouds. It is constructed in terms of a hierarchical architecture with multiple subnetworks, which capture the overall typhoon variations and favor generating clear future typhoon cloud images. The local discriminator tries its best to distinguish generated typhoon cloud images from ground-truth ones, based on the local patches. The local procedure encourages the discriminator to focus on characterizing the moving typhoon clouds rather than the still background. The global generator and the local discriminator are trained in an adversarial fashion with respect to historical typhoon cloud image sequences. The trained HGAN is capable of producing reliable visual predictions that are not only enabled by the global generator and but also examined by the local discriminator. Experiments validate the effectiveness of the HGAN for typhoon cloud prediction