Purified protein derivative skin testing on HIV/AIDS patients and logistic regression analysis of its risk factors

Objective： To understand the reactivity of purified protein derivative skin test（PPD test） in HIV-infected persons and to determine the influential factors associated with PPD. Methods： 174 HIV/AIDS patients registered in the local center for disease control and prevention（CDC） participated this study from April to June in 2006. Questionnaire,CD4 count and thoracic roentgenogram were performed for all participants. Results： In this study, response rate of questionnaires was 83.65%. The majority of these participants had a different degree of immunodeficiency that accounted for 93.64%. Female patients had a higher CD4 count than that of males. The total positive rate of PPD was 38.15%. Analysis of single factor in our study indicated that CD4 count, previous tubereulosis history, tuberculosis contact history and thoracic roentgenogram manifestation of patients were related to their PPD diameters. Further analysis of multiple factors also supports the previous conclusion that CD4 count and previous tuberculosis history of patients were risk factors in the PPD test. Conclusion： The PPD test of HIV/AIDS patients could be affected by several factors. For persons infected with HIV, the confirmation of latent tuberculosis infection （LTBI） should be considered the combination effect of previous MTB infection and body cellular immune function.

Empirical analysis of the farmer's behavior under the new rural financial cooperatives in China

It's been well recognized for the big role played by innovative rural cooperative financial organizations in terms of spreading farmers' operation risk,increasing farmers' income,and developing rural economy.However,no sufficient research has been conducted regarding those factors which may have effects on the farmer's willingness to participate in the new rural financial organization.This paper tries to fill out the gap of identifying various factors which may have potential influence on the farmer's willingness to participate in the new type of rural financial cooperatives.In the process,442 farmer households and small-micro-enterprises are sampled from the cooperative finance experiment villages in Panjin municipality of Liaoning province.The potential influencing factors are classified into four categories,including the famer household's characteristics,financial cooperative reputation,transaction costs,and service quality.A discrete Logit model is used for the parameter estimations.The results show that most assumed factors display statistical significance effect on the farmer's willingness to take part in the rural cooperative financing organizations but with different level of sensitivity.The cause and effect are fully discussed following by addressing policy issues related to the rural financing cooperative reforms.

Numerical modeling and performance evaluation of passive convergence-permeable reactive barrier(PC-PRB)

The passive convergence-permeable reactive barrier(PC-PRB)was proposed to address the limitations of traditional PRB configurations.To evaluate the hydraulic and pollutant removal performance of the PC-PRB system,we developed a simulation code named PRB-Trans.This code uses the two-dimensional(2D)finite element method to simulate groundwater flow and solute transport.Case studies demonstrate that PC-PRB technology is more efficient and cost-effective than continuous permeable reactive barrier(C-PRB)in treating the same contaminated plume.Implementation of PC-PRB technology results in a 33.3%and 72.7%reduction in PRB length(L_(PRB))and height(H_(PRB)),respectively,while increasing 2D horizontal and 2D vertical pollutant treatment efficiencies of PRB by 87.8%and 266.8%,respectively.In addition,the PC-PRB technology has the ability to homogenize the pollutant concentration and pollutant flux through the PRB system,which can mitigate the problems arising from uneven distribution of pollutants in the C-PRB to some extent.The L_(PRB)required for PC-PRB decreases as the water pipe length(L_(p))increases,while the H_(PRB)required initially decreases and then increases with increasing L_(p).The effect of passive well height(Hw)on H_(PRB)is not as significant as that of L_(p)on H_(PRB).Overall,PC-PRB presents a promising and advantageous PRB configuration in the effective treatment of various types of contaminated plumes.