Logistic regression for prediction and diagnosis of bacterial regrowth in water distribution system

This paper focuses on the quantitative expression of bacterial regrowth in water distribution system. Considering public health risks of bacterial regrowth, the experiment was performed on a distribution system of selected area. Physical, chemical, and microbiological parameters such as turbidity, temperature, residual chlorine and pH were measured over a three-month period and correlation analysis was carried out. Combined with principal components analysis (PCA), a logistic regression model is developed to predict and diagnose bacterial regrowth and locate the zones with high risks of microbiology in the distribution system. The model gives the probability of bacterial regrowth with the number of heterotrophic plate counts as the binary response variable and three new principal components variables as the explanatory variables. The veracity of the logistic regression model was 90%, which meets the precision requirement of the model.     

Spatial distribution of Cd and Cu in soils in Shenyang Zhangshi Irrigation Area （SZIA）, China

Heavy metal contamination of soils, derived from sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides, and so on, has been of wide concern in the last several decades. The Shenyang Zhangshi Irrigation Area (SZIA) in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years. This study investigated the spatial distribution and temporal variation of soil cadmium (Cd) and copper (Cu) contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd and Cu in soils was analyzed and then the spatial distribution and temporal variation of Cd and Cu in soils were modeled using Kriging methods. The results show that long-term sewage irrigation had caused serious Cd and Cu contamination in soils. The mean and the maximum of soil Cd are markedly higher than the levels in second grade standard soil (LSGSS) in China, and the maximum of soil Cu is close to the LSGSS in China in 2004 and is more than the LSGSS in China in 1990. The contamination magnitude of soil Cd and the soil extent of Cd con- tamination had evidently increased since sewage irrigation ceased in 1992. The contamination magnitude of soil Cu and the soil extent of Cu contamination had evidently increased in topsoil, but obviously decresed in subsoil. The soil contamination of Cd and Cu was mainly related to Cd and Cu reactivation of contaminated sediments in Shenyang Xi River and the import of Cd and Cu during irrigation. The eluviation of Cd and Cu in contaminated topsoil with rainfall and irrigation water was another factor of temporal-spatial variability of Cd and Cu contamination in soils.     

Experimental and model comparisons of H2O2 assisted UV photodegradation of Microcystin-LR in simulated drinking water

The degradation of Microcystin-LR （MC-LR） in water by hydrogen peroxide assisted ultraviolet （UV/H2O2） process was investigated in this paper. The UV/H2O2 process appeared to be effective in removal of the MC-LR. MC-LR decomposition was primarily ascribed to production of strong and nonselective oxidant-hydroxyl radicals within the system. The intensity of UV radiation, initial concentration of MC-LR, MC-LR purity, dosages of H2O2, the initial solution pH, and anions present in water, to some extent, influenced the degradation rate of MC-LR. A modified pseudo-first-order kinetic model was developed to predict the removal efficiency under different experimental conditions.     

基于系统动力学视野的职业教育

以系统的观点和系统动力学的思想对职业教育在教育大系统和社会系统中所占有的地位和发挥的重要作用作了分析,并对职业教育遇到的问题和解决思路进行了探讨。     

Effect of tramadol on immune responses and nociceptive thresholds in a rat model of incisional pain

Objective: To evaluate the effects oftramadol on the proinflammatory responses in a rat model of incisional pain by investigating its effects on nociceptive thresholds and serum interleukin-6 (IL-6) and IL-2 levels. Methods: Forty-two male Sprague-Dawley (SD) rats scheduled for plantar incision were randomly divided into 7 groups (n=6 in each group). Rats in Group 1 receiving general anesthesia with no incision were served as control; At 30 min before skin incision, Groups 2～5 were given 5 ml normal saline or 1, 10, and 20 mg/kg tramadol, respectively, intraperitoneally (i.p.); Group 6 received 10 mg/kg tramadol after operation; Group 7 received 10 mg/kg tramadol before incision, followed by 200 μg/kg naloxone after operation. Mechanical allodynia was measured by electronic von Frey filament to evaluate the nociceptive thresholds 1 h before incision, and 1 h and 2 h after operation. Serum IL-6 and IL-2 levels were measured by enzyme-linked immunosorbent assay (ELISA) 2 h after operation. Results: Mechanical thresholds decreased significantly and serum IL-6 level increased significantly after operation in Group 2 compared with control (P＜0.01), and these changes were reversed respectively by tramadol in a dose-dependent manner (P＜0.05 and P＜0.01, respectively). IL-2 level remained unchanged after operation in Group 2, but decreased in Group 3 (P＜0.05), then gradually returned to the normal level in Groups 4 and 5. The intraperitoneally injected tramadol (10 and 20 mg/kg) produced a potent and dose-dependent antinocicptive effect on the lesioned paw. The antinocicptive effects of tramadol were partially an-tagonized by naloxone (200 μg/kg), suggesting an additional non-opioid mechanism. Conclusion: The results suggest that tramadol could be a good choice for the treatment of pain under the conditions that immunosuppression may be particularly contraindicated.     

Investigations on control algorithm of steady-state cornering and control strategy for dynamical correction in a steer-by-wire system

To improve the handling performance of a steer-by-wire （SBW） vehicle, a series of control logics are proposed. Firstly, an algorithm for enhancing the maneuvering in steady-state cornering is presented. On this basis, two categories of control strategies are used to dynamically correct and compensate the transient state steering responses and vehicle behaviors. Simulator tests including subjective evaluations and virtual field tests are both conducted to make comprehensive investigations on the series of control logics. The subjective evaluations demonstrate that the SBW vehicle with a specifically selected value of steering sensitivity tends to be more desirable for driving than a conventional one in which a fixed steering ratio exists. The virtual field tests indicate that the control strategies for dynamical correction and compensation could effectively improve the handling per- formances of an SBW vehicle by reducing the work load of drivers, enhancingthe track-holding performance, and improving steering response properties.     

Effect of a distal protection device on epicardial blood flow and myocardial perfusion in primary percutaneous coronary intervention

Objective: The beneficial effect of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has been well established, but there is the problem of no-reflow phenomenon which is an adverse prognostic factor in primary PCI. In the present study the effect of a distal protection device (PercuSurge GuardWire; GW) on epicardial blood flow and myocardial perfusion was evaluated. Methods and Results: Patients with AMI were randomly divided into 2 groups, the GW and the control groups. The GW group included 52 patients with AMI who underwent primary PCI with GW protection and the control group included 60 patients who underwent primary PCI without GW protection. Epicardial blood flow in the infarct-related artery (IRA) and myocardial perfusion were evaluated according to the thrombolysis in myocardial infarction (TIMI) flow grade and the myocardial blush grade (MBG). We found TIMI score of 3 was obtained significantly more frequently in the GW group (96%) than in the control group (80%). The MBG score of 3 was obtained also significantly greater in the GW group (65%) than in the control group (33%). Conclusion: Primary PCI with GW protection can significantly improve epicardial blood flow and myocardial perfusion.     

提升新建本科院校工程教育研究水平的实证研究——基于福建工程学院2005-2014年研究文献的可视化分析

利用CiteSpace软件,通过定量分析CNKI平台上收录的文献,首次对福建工程学院教师发表的工程教育期刊研究论文进行计量学研究和可视化分析,以此了解学校教师对工程教育研究领域的关注度及研究的发展轨迹,指出存在的问题及与国际工程教育研究关注热点的差距,并就提高学校教育研究水平提出建议。     

Quantitative evaluation of air pollution in transport strategic environmental assessment: a case study based on uncertainty analysis and graphic information system technology

Although the impact of road transport on urban air quality has achieved a high profile in China, still greater attention is required as it has not yet been considered fully even in relation to the road network linking cities and urban areas. Strategic environmental assessment （SEA） is a systematic and comprehensive process for evaluating the environmental impacts of a policy, plan or program in publicly accountable decision-making. Air pollution has been recognized as a significant issue in most transport SEA practices. The Strategic Environmental Assessment of the Hubei Road Network Plan （2002-2020） （HRNP） was introduced as one of the World Bank＇s pilot SEA projects. An effective framework was developed to investigate the functional relationship between the road network and its potential air pollutant emissions. In this study, two indicators were identified： emission intensity/ inventory of pollutants and the spatial distribution of the most polluted areas. Because strategic actions are inherently nebulous and data quality is often disappointing, three alternative scenarios were employed to address uncertainties and data/scale issues. Calculations were made using emission models and results were analyzed with the help of statistical tools and the geographic information system （GIS）. The results from the project implementation and the feedback from the World Bank have both shown that the proposed framework is effective in the transport SEA process.