Sustainable land use changes in the north west provinces of China under the conversion of cropland to forest and grassland program

With increasing resource use pressure, land degradation in China has become increasingly severe in the past few decades especially in North West China. The Conversion of Cropland to Forest and Grassland Program (CCFGP), also known as the Grain for Green Program, was formally launched in 2002 to address the land degradation issue. Under the CCFGP, participating farmers are supported by the Government to grow trees and grass on land previously used for annual cropping. With government funding for the CCFGP drawing to an end in 2007, increasing attention amongst the Chinese policy makers, as well as the wider Chinese and international communities, has been devoted to the long-term sustainability of the land use changes triggered by the CCFGP. Question also remains as to whether there are better ways to deliver the anticipated policy outcome. In this thesis, a cost benefit analysis of the CCFGP is conducted to justify government intervention in providing the environmental goods and services through public finance. The potential efficiency gain of the Program is examined, based on which the sustainability of the land use changes under the Program together with the cost-effectiveness of the Program is explored. This partial cost benefit analysis of the CCFGP is conducted over a 20-year time period in the North West Provinces of China. Costs and benefits included in the analysis encompass the welfare impact of the land use changes on agricultural production and the environmental costs and benefits arising from the land use changes under the Program. Due to the limitation of data availability, some components of the environmental benefits and costs of runoff reductions are not included in the analysis. It has been found through this research that the livelihoods of participating farm households are improved by the CCFGP and the Program has positive impact on the social welfare of the local communities. The biophysical changes under the Program bring about both on-site and off-site benefits and costs. While the Program has been found to generate significant non-market environmental values, it also causes economic losses from reduced agricultural production arising from runoff reductions. Overall, the CCFGP improves the social welfare of people across Northern China over a 20-year time period since its implementation. Conclusion is drawn that government intervention through the CCFGP can be justified and the Program should be supported by the Chinese Government. Theoretically the sustainability of the Program can be achieved. However, sustainable land use changes will also depend on the implementation and design of the CCFGP. Future financing of the CCFGP is needed for some areas where the Program is found to decrease the social welfare of the local communities. Finally, there is room for better environmental targeting of the Program to improve the cost-effectiveness of the Program. The institution of an auction mechanism to allocate CCFGP funds more efficiently offers one potential solution

Towards the Identification of Protein Complexes and Functional Modules by Integrating PPI Network and Gene Expression Data

Background: Identification of protein complexes and functional modules from protein-protein interaction (PPI) networks is crucial to understanding the principles of cellular organization and predicting protein functions. In the past few years, many computational methods have been proposed. However, most of them considered the PPI networks as static graphs and overlooked the dynamics inherent within these networks. Moreover, few of them can distinguish between protein complexes and functional modules. Results: In this paper, a new framework is proposed to distinguish between protein complexes and functional modules by integrating gene expression data into protein-protein interaction (PPI) data. A series of time-sequenced subnetworks (TSNs) is constructed according to the time that the interactions were activated. The algorithm TSN-PCD was then developed to identify protein complexes from these TSNs. As protein complexes are significantly related to functional modules, a new algorithm DFM-CIN is proposed to discover functional modules based on the identified complexes. The experimental results show that the combination of temporal gene expression data with PPI data contributes to identifying protein complexes more precisely. A quantitative comparison based on f-measure reveals that our algorithm TSN-PCD outperforms the other previous protein complex discovery algorithms. Furthermore, we evaluate the identified functional modules by using “Biological Process” annotated in GO (Gene Ontology). The validation shows that the identified functional modules are statistically significant in terms of “Biological Process”. More importantly, the relationship between protein complexes and functional modules are studied. Conclusions: The proposed framework based on the integration of PPI data and gene expression data makes it possible to identify protein complexes and functional modules more effectively. Moveover, the proposed new framework and algorithms can distinguish between protein complexes and functional modules. Our findings suggest that functional modules are closely related to protein complexes and a functional module may consist of one or multiple protein complexes. The program is available at http://netlab.csu.edu.cn/bioinfomatics/limin/DFM-CIN/index

随机需求下的WEEE双回收渠道管理研究

More and more enterprises collecting e-wastes through the online recycling channel as the rapidly improving of the customer acceptance of the online recycling channel. And they are facing a problem, however, that they have to offer a higher price in the online recycling channel than the traditional recycling channel as well as reducing the searching cost by using the online recycling channel. Base on that, we incorporate a detailed consumer recycling channel choice model where the collection quantity faced in each channel relies on both the excessive price level in the online recycling channel and the waiting or timing cost in the traditional recycling channel with stochastic demand. Furthermore, three reverse channel models are addressed to derive the optimal decisions, collection quantities as well as the maximal profits. The result shows that the dual-recycling channel strategies that depends on the excessive price level, searching or timing cost, and the demand of the processed products. Moreover, we also depicted that when these enterprises should establish dual recycling channel if they are already have one of these recycling channel, with the change of the demand and excessive price level

随机需求下的WEEE双回收渠道管理研究

More and more enterprises collecting e-wastes through the online recycling channel as the rapidly improving of the customer acceptance of the online recycling channel. And they are facing a problem, however, that they have to offer a higher price in the online recycling channel than the traditional recycling channel as well as reducing the searching cost by using the online recycling channel. Base on that, we incorporate a detailed consumer recycling channel choice model where the collection quantity faced in each channel relies on both the excessive price level in the online recycling channel and the waiting or timing cost in the traditional recycling channel with stochastic demand. Furthermore, three reverse channel models are addressed to derive the optimal decisions, collection quantities as well as the maximal profits. The result shows that the dual-recycling channel strategies that depends on the excessive price level, searching or timing cost, and the demand of the processed products. Moreover, we also depicted that when these enterprises should establish dual recycling channel if they are already have one of these recycling channel, with the change of the demand and excessive price level

Regeneration of Different Plant Functional Types in a Masson Pine Forest Following Pine Wilt Disease

Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation