Integrated impact analysis of yellow-dust storms : a regional case study in China

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2003.Includes bibliographical references (leaves 120-126).The dust storm is a meteorological event that is caused by strong winds and proceeds from arid and semi-arid regions, transporting a thick cloud of fine sediments. In China, the sediments of dust storms mainly come from the desert and thus are called "yellow-dust storms." Although these storms can disrupt socioeconomic activities widely and pose hazards to human health as well as to the ecosystem, no one has made a systematic socioeconomic analysis of yellow-dust storms. I provide an integrated regional socioeconomic framework to quantify the impacts of yellow-dust storms, as a conceptual model and a demonstration of applicable methodologies. I conduct a case study using 2000 Beijing data, mainly applying input-output analysis, dose-response analysis, and a benefit-transfer approach, and test my results with sensitivity analysis. I demonstrate that the economic impacts of yellow-dust storms have reached all sectors of the regional economy, and that their delayed impacts were more significant than the immediate impacts. Further, I clarify the extent of the economic impacts of yellow-dust storms by both backward and forward linkage analyses. On the basis of both quantitative and qualitative analysis results, I discuss the policy implications of yellow-dust control and show that water-resource planning is critical both for the prevention and mitigation of yellow-dust storm problems.by Ning Ai.M.C.P

The Application of Theme/rheme Coherence Device in Discourse Teaching under Cognitive Framework

The repetitive coherence of theme and rheme comes through one of the important cohesive devices which make texture coherent and progressing. From cognitive point of view, applying the mode of thematic and rheme into English language teaching can display its tool function for texture. It also contributes to the understanding and interpretation of coherent discourses, and to the way in teaching reading and writing. Therefore，learners will leap forward from their cognitive level. Key words: cognition, coherence of theme and rheme, English language teaching Résumé: Le raccordement répété de thème-rhème est un des moyens importants de réaliser la cohérence et la continuité du texte. Et c’est grâce à ces moyens de cohérence que le texte s’acquiert la cohésion. L’application du système de cohérence à l’enseignement du texte anglais montre son utilité comme instrument textuel, offre de nouvelles perspectives pour l’enseignement de rédaction et de lecture en anglais, et aide les apprenants à approfondir leur compréhension. Mots-clés: cognition, cohérence de thème-rhème, enseignement textuel 摘要：語篇中主述位的反復銜接是實現語篇銜接和連貫的重要手段之一，而正是這些語篇銜接的手段使得主、述位達到層層推進，構成連貫的語篇。從認知的角度將主述位銜接機制應用於英語篇章教學，可展示其作為篇章工具的使用性，也可以為英語寫作和閱讀教學提供更為清新的思路，使英語學習者從認知上達到一個飛躍。 關鍵詞：認知；主述位銜接；篇章教

Deep Joint Encryption and Source-Channel Coding: An Image Visual Protection Approach

Joint source and channel coding (JSCC) has achieved great success due to the introduction of deep learning. Compared with traditional separate source channel coding (SSCC) schemes, the advantages of DL based JSCC (DJSCC) include high spectrum efficiency, high reconstruction quality, and the relief of "cliff effect". However, it is difficult to couple encryption-decryption mechanisms with DJSCC in contrast with traditional SSCC schemes, which hinders the practical usage of the emerging technology. To this end, our paper proposes a novel method called DL based joint encryption and source-channel coding (DJESCC) for images that can successfully protect the visual information of the plain image without significantly sacrificing image reconstruction performance. The idea of the design is using a neural network to conduct image encryption, which converts the plain image to a visually protected one with the consideration of its interaction with DJSCC. During the training stage, the proposed DJESCC method learns: 1) deep neural networks for image encryption and image decryption, and 2) an effective DJSCC network for image transmission in encrypted domain. Compared with the perceptual image encryption methods with DJSCC transmission, the DJESCC method achieves much better reconstruction performance and is more robust to ciphertext-only attacks.Comment: 12 pages, 13 figure

Deep Joint Source-Channel Coding for Image Transmission With Visual Protection

Joint source-channel coding (JSCC) has achieved great success due to the introduction of deep learning (DL). Compared to traditional separate source-channel coding (SSCC) schemes, the advantages of DL-based JSCC (DJSCC) include high spectrum efficiency, high reconstruction quality, and relief of “cliff effect”. However, it is difficult to couple existing secure communication mechanisms (e.g., encryption-decryption mechanism) with DJSCC in contrast with traditional SSCC schemes, which hinders the practical usage of this emerging technology. To this end, our paper proposes a novel method called DL-based joint protection and source-channel coding (DJPSCC) for images that can successfully protect the visual content of the plain image without significantly sacrificing image reconstruction performance. The idea of the design is to use a neural network to conduct visual protection, which converts the plain image to a visually protected one with the consideration of its interaction with DJSCC. During the training stage, the proposed DJPSCC method learns: 1) deep neural networks for image protection and image deprotection, and 2) an effective DJSCC network for image transmission in the protected domain. Compared to existing source protection methods applied with DJSCC transmission, the DJPSCC method achieves much better reconstruction performance

Effective Silencing of Sry Gene with RNA Interference in Developing Mouse Embryos Resulted in Feminization of XY Gonad

Delivering siRNA or shRNA into the developing embryos is still a main challenge to use of RNAi in mammalian systems. Here we analyze several factors influencing RNAi-mediated silencing of Sry gene, which is a tightly controlled spatiotemporal expressed gene and only shortly expressed in developing mouse embryo gonad. A Sry gene-specific shRNAs expression vector (pSilencer4.1/Sry565) was constructed. The shRNA constructs were mixed with polyethylenimines (PEIs) to form a complex and then injected into pregnant mice though tail vein. Our results showed that Sry gene was downregulated significantly in developing embryos. Further study revealed that knocking-down of Sry expression resulted in feminization of gonad development in mouse embryos and the expression level of Sox9 and Wt1 gene was also significantly changed by downregulation of Sry. The transfection efficiency is associated with the amount of plasmid DNA injection, injection time, injection speed, and volume. Our studies suggest that transplacental RNAi could be implemented by tail vein injection of plasmid vector into pregnant mice

Expression of VP60 gene from rabbit haemorrhagic disease virus (RHDV) YL strain under control of the ats1A promoter in tobacco

The VP60 gene from rabbit haemorrhagic disease virus (RHDV) YL strain in Northeast of China, under control of the ats1A promoter from Rubisco small subunit genes of Arabidopsis thaliana, was introduced into the transfer deoxyribonucleic acid (T-DNA) region of plant transfer vector pCAMBIA1300 and transferred to tobacco (Nicotiana tabacum cv. Petit Havanna SR1) with Agrobacterium tumefaciens-mediated method. Polymerase chain reaction (PCR) reverse transcription(RT) and -PCR analysis of the transformed tobacco plants confirmed the integration of the VP60 gene copy into the plant DNA and VP60 gene transcription produced. Western blot analysis revealed that the VP60 protein was expressed in tobacco under control of ats1A promoter.Key words: Agrobacterium tumefaciens, rabbit haemorrhagic disease virus (RHDV), VP60 protein, ats1A promoter, plant-derived vaccine

Cell Cycle Regulators and Lineage-Specific Therapeutic Targets for Cushing Disease

Cell cycle proteins are critical to pituitary development, but their contribution to lineage-specific tumorigenesis has not been well-elucidated. Emerging evidence from in vitro human tumor analysis and transgenic mouse models indicates that G1/S-related cell cycle proteins, particularly cyclin E, p27, Rb, and E2F1, drive molecular mechanisms that underlie corticotroph-specific differentiation and development of Cushing disease. The aim of this review is to summarize the literature and discuss the complex role of cell cycle regulation in Cushing disease, with a focus on identifying potential targets for therapeutic intervention in patients with these tumors