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To assess the complementary value of high-resolution multi-contrast MRI (hrMRI) in identifying symptomatic patients with intracranial atherosclerosis (ICAS) who are likely to experience recurrent ischemic cerebrovascular events.In this retrospective cohort study, eighty patients with acute ischemic events attributed to ICAS who underwent hrMRI examination between January 2015 and January 2019 were included. Median follow-up for all patients was 30 months (range: 1 to 52 months) and recurrent ischemic cerebrovascular events were recorded. Cox regression analysis and time-dependent ROC were performed to quantify the association between the plaque characteristics and recurrent events.During the follow-up, 14 patients experienced recurrent ischemic cerebrovascular events. Young males and those with diabetes and poor medication persistence were more likely to experience recurrent events. ICAS in patients with recurrence had significantly higher enhancement ratio and steepness which is defined as the ratio between the plaque height and length than those without (p0.001 and p = 0.015, respectively). After adjustment of clinical factors, enhancement ratio (HR, 13.13 [95% CI, 3.58-48.20], p0.001) and plaque steepness (HR, 110.27 [95% CI, 4.75-2560.91], p = 0.003) were independent imaging biomarkers associated with recurrent events. Time-dependent ROC indicated that integrated high enhancement ratio and steepness into clinical risk factors improved discrimination power with the ROC increased from 0.79 to 0.94 (p = 0.008).The enhancement ratio and plaque steepness improved the accuracy over traditional clinical risk factors in predicting recurrent ischemic cerebrovascular events for patients with ICAS.• High-resolution magnetic resonance imaging helps clinicians to evaluate high-risk Intracranial plaque. • The higher enhancement ratio and plaque steepness (= height/length) were the primary biomarkers associated with future ischemic cerebrovascular events. • High-resolution magnetic resonance imaging combined with clinical characteristics showed a higher accuracy for the prediction of recurrent events in patients with intracranial atherosclerosis.

China has recently implemented a policy to promote potato as a national staple food and to close its large yield gaps with other countries. The carbon–land–water implications of this policy are examined here by compiling and analysing detailed city-level life-cycle inventories of China’s staple crops. We find that in general potato, despite relatively low yields, has lower greenhouse gas emissions and water demand than other staple crops (maize, wheat and rice) on a per-calorie basis, but substantial regional variation exists for each crop. Integrating potato as a staple in China to meet increases in food demand and close the yield gap has the potential to reduce the total carbon–land–water impacts of staple crops by 17–25% by 2030. However, an unsuccessful integration runs the risk of global burden-shifting if the policy, for example, reduced domestic rice production and led to increased rice imports. Potential synergies between food security and environmental sustainability in China can be created by the potato policy, but greater efforts are needed to promote potato across the entire food supply chain from production to consumption. The policy of integrating potato as a staple of the diet in China has potential to improve food security. Here, it is shown that successful integration may also reduce total carbon–land–water impacts of staple crops in China by up to 25% by 2030.

China’s rapid economic growth has caused severe air pollution and public health problems. Therefore, the Chinese government launched the National Air Pollution Control Plan (hereinafter referred to as the “Air Plan”) in 2013–2017 to improve air quality and safeguard public health. In this study, an analytical framework for a cost-benefit analysis applicable to China was constructed, and the costs and benefits of the implementation of the “Air Plan” in 30 cities and provinces in China from 2013 to 2017 were evaluated. Results show that the total cost of implementation of the “Air Plan” is 1.6511 trillion RMB. The benefits of air quality improvement were determined to be 2.4691 trillion RMB through the willingness-to-pay method to calculate the economic loss of premature deaths. The net benefit related to the implementation of the “Air Plan” was 818 billion RMB. The public health benefit of air quality improvement was 1.5 times the cost of the nationwide implementation of the “Air Plan”. At the provincial level, net benefits that reach 279.3 billion RMB were the highest in Guangdong, whereas the benefit-cost ratio, where the benefit was 5.5 times the cost, was the highest in Fujian. Estimations in this study can serve as a reference for China in formulating similar environmental policies and implementing the “3-year Plan to Defend the Blue Sky”. In addition, these estimations have practical significance for advancing the long-term effective mechanisms of the cost-benefit analysis of China’s environmental policies.

With the continuous occurrence of natural disasters, natural hazard triggered technological accident (Natech) risks also follow. At present, many countries have performed much research on Natech risks. However, there is still a lack of Natech research at the regional or watershed level in China. The Yangtze River Economic Belt (YREB) is not only an industrially intensive development area but also an area with frequent natural disasters. In this study, we selected the YREB as a typical case to study the Natech risk triggered by floods, geological disasters, and typhoons at the regional or watershed level. Four types of risk indicators representing risk sources, natural hazard factors, control levels, and vulnerabilities were developed to assess the spatial patterns of the Natech risks of the YREB. The results show that the Natech risk triggered by floods and typhoons is more serious in eastern area and central area than in western zone and that the Natech risk triggered by geological disasters is more serious in the west part. Approximately 7.85% of the areas are at relatively high-risk and above the Natech risk level based on the comprehensive assessment of three types of Natech risks. The combined population of these areas accounts for approximately 15.67% of the whole YREB, and the combined GDP accounts for approximately 25.41%. It can be predicted that the occurrence of Natech risks in these areas will cause serious harm to both the people and the economy. This work will provide the basis and key management direction for Natech risk management in the YREB.

China pledges to peak CO2 emissions by 2030 or sooner under the Paris Agreement to limit global warming to 2 °C or less by the end of the century. By examining CO2 emissions from 50 Chinese cities over the period 2000–2016, we found a close relationship between per capita emissions and per capita gross domestic product (GDP) for individual cities, following the environmental Kuznets curve, despite diverse trajectories for CO2 emissions across the cities. Results show that carbon emissions peak for most cities at a per capita GDP (in 2011 purchasing power parity) of around US$21,000 (80% confidence interval: US$19,000 to 22,000). Applying a Monte Carlo approach to simulate the peak of per capita emissions using a Kuznets function based on China’s historical emissions, we project that emissions for China should peak at 13–16 GtCO2 yr−1 between 2021 and 2025, approximately 5–10 yr ahead of the current Paris target of 2030. We show that the challenges faced by individual types of Chinese cities in realizing low-carbon development differ significantly depending on economic structure, urban form and geographical location. Chinese commitments under the Paris Agreement are premised on a peak in CO2 emissions by 2030. Using the Kuznets curve and emissions and gross domestic product data from 50 cities in the country, this Analysis predicts that emissions in China could peak between 2021 and 2025, well ahead of the Paris target.

Background Nowadays, colorectal cancer (CRC) is one of the most commonly diagnosed malignant tumors worldwide, the incidence rate of which is still increasing year by year. Herein, the objective of this study is to investigate whether CDC42EP3 has regulatory effects in CRC. Methods First, CDC42EP3 knockdown cell model based on HCT116 and RKO cell lines was successfully constructed, which was further used for constructing mouse xenotransplantation models. Importantly, effects of CDC42EP3 knockdown on proliferation, colony formation, apoptosis, and migration of CRC were accessed by MTT assay, EdU staining assay, colony formation assay, Flow cytometry, and Transwell assay. Results As the results, we showed that CDC42EP3 was significantly upregulated in CRC, and its high expression was associated with tumor progression. Furthermore, knockdown of CDC42EP3 could inhibit proliferation, colony formation and migration, and promote apoptosis of CRC cells in vitro. In vivo results further confirmed knockdown of CDC42EP3 attenuated tumor growth in CRC. Interestingly, the regulation of CRC by CDC42EP3 involved not only the change of a variety of apoptosis-related proteins, but also the regulation of downstream signaling pathway. Conclusion In conclusion, the role of CDC42EP3 in CRC was clarified and showed its potential as a target of innovative therapeutic approaches for CRC.

Recently the AMS-02 reported the precise measurements of the energy spectra of medium-mass compositions (Neon, Magnesium, Silicon) of primary cosmic rays, which reveal different properties from those of light compositions (Helium, Carbon, Oxygen). Here we propose a nearby source scenario, together with the background source contribution, to explain the newly measured spectra of cosmic ray Ne, Mg, Si, and particularly their differences from that of He, C, O. Their differences at high energies can be naturally accounted for by the element abundance of the nearby source. Specifically, the abundance ratio of the nearby source to the background of the Ne, Mg, Si elements is lower by a factor of $\sim1.7$ than that of the He, C, O elements. Such a difference could be due to the abundance difference of the stellar evolution of the progenitor star or the acceleration process/environment, of the nearby source. This scenario can simultaneously explain the high-energy spectral softening features of cosmic ray spectra revealed recently by CREAM/NUCLEON/DAMPE, as well as the energy-dependent behaviors of the large-scale anisotropies. It is predicted that the dipole anisotropy amplitudes below PeV energies of the Ne, Mg, Si group are smaller than that of the He, C, O group, which can be tested with future measurements., 6 pages, 3 figures; accepted for publication in Frontiers of Physics

Traffic networks are often perturbed by temporal events, which generally cause capacity on the links to drop. A capacity drop can lead to fluctuations in flows and travel costs and can further cause congestion. Most day-to-day models have focused on how to describe traveler choice dynamics based on general information, but few studies have considered how to design reasonable information to guide traveler choice behaviors under day-to-day dynamics. In this paper, a day-to-day traffic assignment model is proposed that considers the cost difference between the estimated travel cost on the current day and the actual cost on the previous day to capture traveler path-switching behaviors under advanced information. Our aim is to better understand the dynamic evolution of network flow under information provision. In the model, both the travel cost and cost difference have influences on traveler path-switching behaviors. The linear stability of the equilibrium is analyzed. Compared with the system without the cost difference, the introduction of the cost difference appears to enlarge the stable equilibrium region and reduce the fluctuations in cost and flow under reasonable parameter settings. Additionally, three scenarios are used to examine the influence of the cost difference under a capacity drop. The results show that the cost difference can avoid rapid propagation of congestion induced by a temporal capacity drop. This study explains the influence of the cost difference on the evolutionary pattern of the transportation networks and offers guidance for network design and management.

This study evaluated the myocardial strain and aortic elasticity in patients with bicuspid aortic valve (BAV) and then investigated the relation between them. Thirty-nine patients (30 males; mean age 44±19 years; range 6 to 75 years) with BAV were recruited as BAV group, and 29 age- and sex-matched healthy controls (21 males; mean age 42±11 years; range 20 to 71 years) served as control group. Aortic strain, distensibility and stiffness index were derived using M-mode echocardiography. Left ventricular global myocardial strain was acquired with speckle-tracking echocardiography. Correlation between aortic elasticity and myocardial strain was also analyzed. The results showed that aortic stiffness was higher (17.5±14.0 vs. 5.3±2.7, P

Maintaining balance between convergence and diversity is of great importance for many-objective evolutionary algorithms. The recently suggested non-dominated sorting genetic algorithm III could obtain a fair diversity but the convergence is unsatisfactory. For this purpose, an improved NSGA-III algorithm based on objective space decomposition (we call it NSGA-III-OSD) is proposed for enhancing the convergence of NSGA-III. Firstly, the objective space is decomposed into several subspaces by clustering the weight vectors uniformly distributed in the whole objective space and each subspace has its own population. Secondly, individual information is exchanged between subspaces in the mating selection phase. Finally, the convergence information is added in the environmental selection phase by the penalty-based boundary intersection distance. The proposed NSGA-III-OSD is tested on a number of many-objective optimization problems with three to fifteen objectives and compared with six state-of-the-art algorithms. Experimental results show that NSGA-III-OSD is competitive with the chosen state-of-the-art designs in convergence and diversity.

Software-defined networking (SDN) scheme decouples network control plane and data plane, which can improve the flexibility of traffic management in networks. OpenFlow is a promising implementation instance of SDN scheme and has been applied to enterprise networks and data center networks in practice. However, it has less effort to spread SDN control scheme over the Internet to conquer the ossification of inter-domain routing. In this paper, we further innovate to the SDN inter-domain routing inspired by the OpenFlow protocol. We apply SDN flow-based routing control to inter-domain routing and propose a fine-granularity inter-domain routing mechanism, named SDI (Software Defined Inter-domain routing). It enables inter-domain routing to support the flexible routing policy by matching multiple fields of IP packet header. We also propose a method to reduce redundant flow entries for inter-domain settings. And, we implement a prototype and deploy it on a multi-domain testbed.

Currently, the architecture of network device is closed. This is detrimental to the network innovation. Software defined networking (SDN) (McKeown 2009) decouples the vertically coupled architecture, and reconstructs the Internet as a modular structure. The idea of SDN is widely accepted by both of the academic and industry researchers, and is considered as a promising way to re-architect the Internet. OpenFlow as a typical instance of the SDN has been deployed by many universities and research institutions all over the world. However, the research and technologies on transitioning the existing networks to SDN are not mature. So this paper takes the instance OpenFlow for example and proposes a simple and practical Border Gateway Protocol (BGP) based transition solution named BTSDN. BTSDN fully explores the characteristics of OpenFlow network, proposes to continue using the current BGP protocol, and retains the legacy BGP border routers to connect the OpenFlow network with the rest of Internet. The experiment at the end of this paper preliminary verifies the feasibility of BTSDN.

Battery electric logistics vehicles (BELVs) reduce transportation costs and air pollution unlike conventional logistics vehicles. However, the limited driving range of BELVs creates new problems for logistics transport. Accurate driving distance estimation of BELVs can help logistics companies determine transport strategies and alleviate the range anxiety of drivers. Based on mass data from BELVs operating in Beijing, China, this study uses a practical and effective data-based modeling method, regression analysis, to establish the data-based model of driving distance estimation. During the modeling process, a nonlinear relation between percentage of energy consumption per kilometer and driving speed is explored based on the experimental data. After determining the model variables, the model frame of driving distance in consideration of driving speed and state of charge is established. The forgetting factor recursive least-squares algorithm is applied to estimate the parameter values of the model. Verification results confirm the feasibility of the model and show that the model errors are small. The proposed model is also used to explore the economical driving speed of BELVs.

Background The majority of eukaryote genomes can be actively transcribed into non-coding RNAs (ncRNAs), which are functionally important in development and evolution. In the study of maize, an important crop for both humans and animals, aside from microRNAs and long non-coding RNAs, few studies have been conducted on intermediate-size ncRNAs. Results We constructed a homogenized cDNA library of 50–500 nt RNAs in the maize inbred line Chang 7–2. Sequencing revealed 169 ncRNAs, which contained 58 known and 111 novel ncRNAs (including 70 snoRNAs, 27 snRNAs, 13 unclassified ncRNAs and one tRNA). Forty of the novel ncRNAs were specific to the Panicoideae, and 24% of them are located on sense-strand of the 5′ or 3′ terminus of protein coding genes on chromosome. Target site analysis found that 22 snoRNAs can guide to 38 2’-O-methylation and pseudouridylation modification sites of ribosomal RNAs and small nuclear RNAs. Expression analysis showed that 43 ncRNAs exhibited significantly altered expression in different tissues or developmental stages of maize seedlings, eight ncRNAs had tissue-specific expression and five ncRNAs were strictly accumulated in the early stage of leaf development. Further analysis showed that 3 of the 5 stage-specific ncRNAs (Zm-3, Zm-18, and Zm-73) can be highly induced under drought and salt stress, while one snoRNA Zm-8 can be repressed under PEG-simulated drought condition. Conclusions We provided a genome-wide identification and functional analysis of ncRNAs with a size range of 50–500 nt in maize. 111 novel ncRNAs were cloned and 40 ncRNAs were determined to be specific to Panicoideae. 43 ncRNAs changed significantly during maize development, three ncRNAs can be strongly induced under drought and salt stress, suggesting their roles in maize stress response. This work set a foundation for further study of intermediate-size ncRNAs in maize. Electronic supplementary material The online version of this article (10.1186/s12864-018-5103-1) contains supplementary material, which is available to authorized users.

Contaminated sites will restrict regional development, especially the residential area development as the contamination can pose long-term adverse health risks. Western Suzhou, where three mining areas are located, is a rapid urbanization area in Suzhou City, Jiangsu Province, the People’s Republic of China. This urbanization has been pushing into the mining areas. This study aims to assess the heavy metal contamination (including Cu, Zn, Pb, Cd, Hg, Cr, As, and Ni) and identifies the contaminated sites in Western Suzhou. Fifty soil samples and 34 road dust samples in Western Suzhou including a closed mine (A1), a mineral concentration plant (A2), and a newly opened mine (A3) were collected and analyzed. The geo-accumulation (I geo) methodology, principal component analysis (PCA), spatial interpolation, and health risk assessment were employed for evaluation. The contamination levels are ranked in the orders of Cd > Pb > Zn > Cu > As > Hg > Ni > Cr for soils and Cd > Pb > Zn > Cu > As > Ni > Hg > Cr for road dusts. The concentrations of heavy metals in the road dusts are generally higher than those in soils. Copper, Zn, Pb, Cd, and As are the main contaminants and mainly due to mining activities. Lead, Cd, and As in the soils and road dusts in the three mining areas pose high non-carcinogenic risk to children. Spatial analysis shows that the soils and road dusts in areas A1 and A2 have the highest concentrations of heavy metals, followed by area A3, where only the road dust exhibits high concentrations. The results show that there exist contaminated sites in areas A1 and A2 and remediation measures are urgently needed.

Influent river carrying nutrient pollutants from watershed loads makes a great contribution to the eutrophication in river-fed lake. It is scientific standard to make policies on river pollution control based on loading capacity of the river of interest. To control eutrophication in Taihu Lake has been the focal point of “The Twelfth Five-Year Guideline” proposed by Chinese government. The Taigeyunhe, Caoqiaohe and Yincungang Rivers which were the most polluted influent rivers in Taihu Lake Basin were scheduled for nutrient total maximum daily load (TMDL). A variety of mechanistic and empirical models are applied worldwide for TMDL development. However, model selection depends on management objectives, site-specific characteristics and availability of data resource. In this study, based on watershed characteristics and limited data, a nutrient TMDL is developed using flow and temporally variable daily load expressions. The simple and effective approaches specify allowable daily maximum loads for controlling on instantaneous high load and allowable daily median loads for achieving long-term TMDL allocation. For the entire river system, loading capacities are much lower during low flows. The maximum percent load reductions for biochemical oxygen demand, ammonia nitrogen, total nitrogen in spring and total phosphorus in winter can be obtained when pollution source inputs seasonally vary. This study provides local authority with two different alternatives in decision-making for pollution control on influent rivers and then to reduce external loads to the lake.

Recently many research efforts have been spent on applying Software Defined Networking (SDN) to mobile and wireless networking to make them adapt to the rapid development and popularity of the mobile Internet. SDN offers programmable devices and centralized control which help to realize customizable and adaptive solutions to meet requirements from diversified mobile networks, devices, applications and so forth. This paper focuses on extending SDN paradigm to mobility handling in the Internet which has been little studied, and proposes design, implementation and deployment of a software-defined IP mobility architecture. The paper also demonstrates evaluations and experiments of the proposal based on both the Mininet platform and a cross-domain SDN testbed. Results prove the feasibility, scalability and high adaptability of the proposal.

Heavy metals and arsenic are well-known carcinogens. However, few studies have examined whether soil heavy metals and arsenic concentrations associate with cancer in the general population. In this ecological study, we aimed to evaluate the association of heavy metals and arsenic in soil with cancer mortality rates during 2005-2010 in Suzhou, China, after controlling for education and smoking prevalence. In 2005, a total of 1683 soil samples with a sampling density of one sample every 4 km(2) were analyzed. Generalized linear model with a quasi-Poisson regression was applied to evaluate the association between town-scale cancer mortality rates and soil heavy metal concentrations. Results showed that soil arsenic exposure had a significant relationship with colon, gastric, kidney, lung, and nasopharyngeal cancer mortality rates and soil nickel exposure was significantly associated with liver and lung cancer. The associations of soil arsenic and nickel exposure with colon, gastric, kidney, and liver cancer in male were higher than those in female. The observed associations of soil arsenic and nickel with cancer mortality rates were less sensitive to alternative exposure metrics. Our findings would contribute to the understanding of the carcinogenic effect of soil arsenic and nickel exposure in general population.

Energy for water heating accounts for an increasing part in residential energy demand in China. An extensive survey was conducted to analyze the determinants of household energy choices for water heaters among residents in Nanjing, China. Two sets of variables were examined as potential influences: building features and household socio-economic characteristics. Results suggest that building features such as gas availability and building structures, and household characteristics such as household head’s education degree and energy-conserving sense are crucial determinants in choosing natural gas as water heater energy. Installation permission for solar water heater, building stories, and residential location serve as determining factors in choosing solar water heaters. Based on these, barriers and opportunities are discussed for transitions toward cleaner water heating energies, and suggestions are given for local governments to promote cleaner energy replacement in China.

The Qixia mine is one of the largest lead-zinc mines in Eastern China and has been operational for approximately 60 years. Source identification for trace element contamination of soils in the Qixia mining area has been lacking. This report details the evaluation and source identification of trace element contamination (including Cu, Zn, Pb, Cd, Hg, Cr, As, and Ni) of soils in this area. Thirty-three soil samples from roadsides and fields in the study area were collected and analyzed. The index of geo-accumulation (I geo) was employed to evaluate contamination. Methods of multivariate statistical analysis were used to determine the probable sources of the pollutants. The analysis showed that the levels of contamination ranked in the following order: Cd > Pb/Zn> > As/Cu> > Hg > Cr/Ni. In the sampling area nearest the mine, soil samples collected from roadsides showed much higher levels of contamination than those collected from fields away from the roadways. Trace element contamination decreased as the distance from the mine increased. Contamination extended to a distance of approximately 700 m from mineral transportation routes, with the area of greatest impact at 200 m or less. Multivariate statistical analysis and ore composition data suggest that the Cu, Zn, Pb, Cd, and As found in the soil samples originate from anthropogenic sources. Ni and Cr are considered to be at natural background concentrations. This study distinguished between natural and anthropogenic sources of trace element contamination in the soils of the Qixia mining area. The contamination of Cu, Zn, Pb, Cd, and As is linked to the mining activities and is likely due to the transportation of ore concentrates and tailings.

Natural gas became an available fuel for taxis in 2005 and had occupied a market share of 43.6% in taxi industry till 2010 in Nanjing, China. To investigate the energy replacement pattern as well as the pollutants reduction potential of the taxi industry, first, the fuel preference determinants of taxi drivers for their next taxis are analyzed. Results show that as an important alternative for the traditional gasoline, natural gas is widely accepted (75%) by taxi drivers. Different from the previous studies which focused on the early stage of cleaner fuel replacement, taxi drivers with various characteristics (such as age, working experience, and education level) are consistent with their fuel preference when they choose their next taxis. Result suggests that policies that concern consumers with specific characteristics may have little effects on the change of the market share, when the alternative fuel market has been developed well. In addition, the increased share of gas in the fuel market achieves a 7.2% reduction of energy consumption. Considering life cycle emissions, the following air pollutants, namely Greenhouse Gases (GHGs), carbonic oxide (CO), nitrogen oxide (NOx), particulate matters (PM) and hydrocarbons (CxHy), gain 10.0%, 3.5%, 20.5%, 36.1%, and 26.4% of reduction respectively. Assuming all taxi fleets powered by natural gas with local policy intervention, the energy conservation and the five major air pollutant emissions could achieve the maximum reductions with 12.2%, 16.0%, 8.8%, 22.5%, 44.2%, and 49.4% correspondingly.

China has suffered from severe earthquake disasters in recent years. In order to explore the impact of severe earthquakes on public risk perception on different time scales, four surveys were conducted twice each after the severe Wenchuan and Yushu earthquakes. t tests were performed between two consecutive surveys to explore the change of public risk attitudes. The results demonstrated that after the two severe earthquakes, the public seismic risk acceptance has increased over time, and the comparison between pre- and post-Yushu earthquake illustrated that the severe disaster had more impact on vulnerable population such as females, children and low-income people. Moreover, linear regression models were employed to find the determining factors of public acceptance towards earthquake risks. It was discovered that the public perceived earthquake effect had significant negative relationship with seismic risk acceptance, and public trust towards local government had positive relationship with the risk acceptance. This study could help government to gain better understanding of public mental status and take more effective disaster preparedness measures when preventing and responding to a severe earthquake.

SDN provides an approach to create desired network forwarding plane by programming applications. For a large-scale SDN network comprised of multiple domains and running multiple controller applications, it is difficult to measure and diagnose the problems of flow tables in data plane. Tracing the forwarding path of SDN is one of effective way for data plane state measurement. Previously proposed methods for debugging SDN were applied to a single administrative domain. There is less effort to trace the flow entries of the data plane in large-scale multi-domain SDN networks. In this paper, we propose a method of software defined data plane tracing in large-scale multi-domain SDN networks. Our method can trace forwarding paths, and get the matched flow entries and other customized trace information. We present the designs compatible with OpenFlow 1.0 and 1.3 switches. The performance and deployment effect are evaluated by simulation test and analysis. It shows that our method has better performance than traditional IP traceroute, and its deployment at about 20\% of AS nodes can enable 70\% of AS paths to be traceable.

To explore the factors that influence respondents’ willingness to pay (WTP) for the risk reduction of chemical industry accidents, a questionnaire survey combined with contingent valuation and psychometric paradigm methods were conducted in the city of Yancheng, Jiangsu Province, China. Both traditional socioeconomic variables and perceived characteristics of the hazards were considered in this study, and a Tobit model was used to find the factors influencing WTP under three risk reduction scenarios. The results showed that three demographic characteristics, age, gender, and income, significantly affected the WTP for chemical risk reduction. In addition, three extracted public risk perception factors, effect, knowledge, and trust, also strongly affected the WTP. The mean WTP value increased as the magnitude of the risk reduction increased. The number of factors influencing the WTP decreased as the reduction level improved, and only the effect factor had a significant influence on the WTP for a higher level (80%) of risk reduction. The cost for chemical safety management of Yancheng was calculated, and the optimized risk reduction level was determined. These findings can assist governments and policy makers to formulate suitable strategies for risk control, to reach target groups of people to develop effective communication, and to provide specific references for the best investment for the security of local residents.

Lead is a cumulative toxicant, which can induce severe health issues, especially in children’s case due to their immature nervous system. While realizing large-scale monitoring of children blood lead remains challenging by utilizing traditional methods, it is highly desirable to search for alternative techniques or novel sensing materials. Here we report a label-free and portable aptasensor based on graphene field effect transistor (FET) for effective children blood lead detection. With standard solutions of different Pb2+ concentrations, we obtained a dose-response curve and a detection limitation below 37.5 ng/L, which is three orders lower than the safe blood lead level (100 μg/L). The devices also showed excellent selectivity over other metal cations such as, Na+, K+, Mg2+ and Ca2+, suggesting the capability of working in a complex sample matrix. We further successfully demonstrated the detection of Pb2+ ions in real blood samples from children by using our aptasensors and explored their potential applications for quantification. Our results underscore such graphene FET aptasensors for future applications on fast detection of heavy metal ions for health monitoring and disease diagnostics.

Because emissions permits can be considered to be a pseudo-commodity, the permit price in the emissions trading markets has already attracted great interest from the economic literature. This research took the Jiangsu sulfur dioxide (SO2) emissions trading program in China as a case study to examine the price dynamics over the next 10 years (2011–2020) based on Jiangsu’s new SO2 emissions trading policy design. An adaptive agent-based simulation model was developed to estimate the price dynamics as well as the impact of energy price, policy design, and new environmental regulation on the permit price. The results showed that the equilibrium price of the Jiangsu SO2 emissions trading market is approximately 4.20 CNY/kg, and the permit price will fluctuate around this price if the other conditions are not changed. If the coal price increases during 2011–2016, the permit price will decline to 2.79 CNY/kg by 2020 under China’s current coal–electricity price mechanism. In addition, the banking mechanism will smooth the price fluctuations and the average permit price will be generally higher when banking is not allowed. Finally, the stricter environmental regulation will reduce the market supply of permits and will raise the permit price. According to China’s potential new SO2 discharge standard, the permit price will jump to 11 CNY/kg. The quantification of the permit price dynamics can help power plants to make decisions on emissions trading.

The various forms of uncertainty that firms may face in bankable emission permit trading markets will affect firms’ decision making as well as their market performance. This research explores the effect of increased uncertainty over future input costs and output prices on the temporal distribution of emission. In a dynamic programming setting, the permit price is a convex function of stochastic prices of coal and electricity. Increased uncertainty about future market conditions increases the expected permit price and causes a risk neutral firm to reduce ex ante emissions in order to smooth out marginal abatement costs over time. Finally, safety valves, both low-side and high-side, are suggested to reduce the impact of uncertainty in bankable emission trading markets.

X-ray diffraction (XRD) was employed to analyze the texture evolution of commercial pure (CP) Ti during cold rolling and recrystallization annealing. The texture components were measured by electron backscattered diffraction (EBSD) after recrystallization annealing. The CP Ti tends to form a texture with the basal pole tilted 30°–40° away from the normal direction toward the transverse direction. The texture of the initial hot-rolled plate can be classified into three kinds, i.e., the pyramid texture $$\left( {\bar 1013} \right)\left[ {5\bar 2\bar 30} \right]$$ and $$\left( {\bar 2021} \right)\left[ {10\bar 15} \right]$$ , the basal plane texture $$\left( {0001} \right)\left[ {2\bar 1\bar 10} \right]$$ , and the stronger prism texture $$\left( {11\bar 20} \right)\left[ {0001} \right]$$ . After cold rolling and annealing (700°C, 60 min), the main texture components are the cold-rolled texture $$\left( {11\bar 25} \right)\left[ {11\bar 23} \right]$$ and the recrystallized texture $$\left( {\bar 1013} \right)\left[ {5\bar 2\bar 30} \right]$$ . The texture $$\left( {\bar 2021} \right)\left[ {10\bar 15} \right]$$ is inherited from the texture of the initial hot-rolled plate with the decrease of orientation density gradually. The volume contents of the cold-rolled texture $$\left\{ {\bar 2115} \right\}\left\langle {01\bar 10} \right\rangle$$ and the recrystallized texture $$\left\{ {10\bar 13} \right\}\left\langle {1\bar 210} \right\rangle$$ are calculated by EBSD. After recrystallization annealing, the specimen is rich in the recrystallized texture and inherits some of texture components from the cold-rolled texture. When the annealing time is prolonged, the anisotropic value decreases.

Organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), dibutyl phthalate (DNBP) and di-2-ethylhexyl phthalate (DEHP) were all detectable in surface water in Jiangsu Province, China. Concentrations of OCPs ranged from 5.13 to 8.15 ng/L. PAHs were found ranging from 14.7 to 24.5 ng/L. Concentrations of DNBP and DEHP ranged from 16 to 5,857.5 ng/L and 556 to 15,670.7 ng/L, respectively. Greater than 70 % of chemicals were removed in water treatment processes. The carcinogenic risks posed by trace organic pollutants through tap water ingestion were lower than 10(-6), and the noncarcinogenic risks were less than 10(-5).

IP traceback can be used to find direct generator(s) and path(s) of attacking traffic. Probabilistic marking schemes, as one type of IP traceback technologies, have been most studied, but they are difficult to fast reconstruct attacking path(s) and defend against spoofed marks generated by attacking source(s). In this paper, we present Adaptive Probabilistic Marking scheme (APM). In APM, when each packet enters the first-hop router, its TTL value is set to a uniform value, and when it is forwarded by routers in the network, each intermediate router decreases the TTL value by one. Consequently, each intermediate router may infer the router-level hop number that each packet has already traveled, and then correspondingly marks the packet with the probability inversely proportional to the router-level hop number. APM is focused on the probability with which a router marks a packet, and APM can cooperate with other probabilistic marking schemes. NS2 simulation experiments prove that, in APM, the time for the victim to receive necessary marks for the path reconstruction is reduced by more than 20% compared with existing probabilistic marking schemes, and spoofed marks cannot reach the victim and influence the traceback process.

Building is one of the main factors of energy use and greenhouse gas emissions. Reducing energy consumption and carbon dioxide (CO2) emission from building is urgent for environmental protection and sustainable development. The objective of this study is to develop a life cycle assessment (LCA) model for an office building in China to assess its energy consumption and CO2 emission, determine the whole life cycle phases, and the significant environmental aspects that contribute most to the impact. A process-based LCA has been used to identify and quantify the energy consumption and CO2 emission of the office building. The LCA is conducted in accordance with the Environmental Protection Agency, The Society of Environmental Toxicology and Chemistry, and the International Organization for Standardization standards for life cycle assessments. The entire life cycle including building materials production, construction, operation, and demolition of the building is studied. A service life of 50 years is assumed and the major construction materials such as concrete, cement, brick, steel, timber, glass, and plastic are selected for the building. The results show that building operation uses the largest share of energy and contributes most to CO2 emission. The cooling and heating system in building operation strongly influence the energy consumption and CO2 emission of the building. In addition, the large quantity use of concrete and steel in materials production, and the treatment of end-of-life building materials are also the important aspects impacting the environmental performance of the building. Based on the results of the study, some environmental improvements aiming at reducing energy consumption and CO2 emission throughout the life cycle of the building are provided. This study provides an LCA of the energy consumption and CO2 emission of a typical office building in China. It determines the whole life cycle phases that contribute most to the impact and defines the significant environmental aspects of the building. This study also shows the importance of using a life cycle perspective when evaluating energy consumption and CO2 emission of building and also lays the groundwork for LCA studying of other office buildings in China.

To avoid the problems of slow and premature convergence of the differential evolution (DE) algorithm, this paper presents a new DE variant named p-ADE. It improves the convergence performance by implementing a new mutation strategy “DE/rand-to-best/pbest”, together with a classification mechanism, and controlling the parameters in a dynamic adaptive manner, where the “DE/rand-to-best/pbest” utilizes the current best solution together with the best previous solution of each individual to guide the search direction. The classification mechanism helps to balance the exploration and exploitation of individuals with different fitness characteristics, thus improving the convergence rate. Dynamic self-adaptation is beneficial for controlling the extent of variation for each individual. Also, it avoids the requirement for prior knowledge about parameter settings. Experimental results confirm the superiority of p-ADE over several existing DE variants as well as other significant evolutionary optimizers.

Directed evolution in vitro is a powerful tool in the study and design of protein function. However, screening the desired mutants is a difficult task. To facilitate the screening, a method is proposed to eliminate wild type sequences and increase mutated DNA sequences, which is based on the preferential binding of MutS protein to heteroduplex DNA. Following error-prone PCR, amplified products are denatured and re-annealed to form heteroduplex and homoduplex DNA. Heteroduplexes are selectively bound to an engineered MutS protein and immobilized on a Strep-Tactin column. Homoduplexes are effectively removed by washing, and the final elution is enriched in mutated DNA sequences. One round of mutated DNA enrichment resulted in an about 2.3-fold of increase in mutation frequency compared to the control. The percentage of mutants rose from 44% in the control sample to 72% in the enrichment sample. Fluorescent assay by flow cytometry showed that the enrichment method increased the mutants with changed fluorescent activity by about 2.2-fold, which strongly justified the efficiency of enrichment in increasing mutants with functional changes. With reduced workload of screening and increased possibility of obtaining mutants with functional changes, the overall efficiency was improved by MutS-mediated enrichment of mutated DNA.

The paper investigates the overall and detailed features of cosmic ray (CR) spectra in the knee region using the scenario of nuclei-photon interactions around the acceleration sources. Young supernova remnants can be the physical realities of such kind of CR acceleration sites. The results show that the model can well explain the following problems simultaneously with one set of source parameters: the knee of CR spectra and the sharpness of the knee, the detailed irregular structures of CR spectra, the so-called "component B" of Galactic CRs, and the electron/positron excesses reported by recent observations. The coherent explanation serves as evidence that at least a portion of CRs might be accelerated at the sources similar to young supernova remnants, and one set of source parameters indicates that this portion mainly comes from standard sources or from a single source., Comment: 13 pages, 4 figures, accepted for publication in SCIENCE CHINA Physics, Mechanics & Astronomy.

In this work we characterize the public perception of one kind of ecological risk-blue-algae bloom in Hongze Lake, China, based on the psychometric paradigm method. In the first survey of May 2008, 300 respondents of Sihong County adjacent to Hongze Lake were investigated, with a total of 156 questionnaires returned. Then in a second survey of July 2008, 500 respondents from the same research area were investigated, with 318 questionnaires collected. This research firstly attempted to explore the local respondents' degree of concern regarding ecological changes to Hongze Lake in the last ten years. Secondly, to explore the public perception of blue-algae bloom compared to three typical kinds of hazards including earthquake, nuclear power and public traffic. T-test was used to examine the difference of risk perception in these four hazards over time. The third part of this research, with demographic analysis and nonparametric statistical test, predicted the different groups of respondents' willingness to accept (WTA) risk of blue-algae bloom in two surveys. Using multiple linear regression analysis, the risk perception model explained 28.3% of variance in the WTA blue-algae bloom risk. The variables of Knowledge, Social effect, Benefit, Controllability and Trust in government were significantly correlated with WTA, which implied that these variables were the main influencing factors explaining the respondents' willingness to accept risk. The results would help the Chinese government to comprehend the public's risk perception of the lake ecosystem, inducing well designed communication of risks with public and making effective mitigation policies to improve people's rational risk judgment.

In this work, both experimental and modeling approaches are used to explore the formation of soluble microbial products (SMP) by activated sludge under anoxic conditions. With substrate consumption, the SMP concentration increases gradually. Utilization associated products (UAP) are the main fraction of SMP when substrate is present; whereas biomass associated products (BAP) are the major content of SMP as substrate is completely consumed. The fraction of the accumulated SMP accounts for 3-4% of initial organic substrate. Three dimensional excitation emission matrix analysis results indicate that the SMP concentration increases in the denitrification process. The accumulation of nitrite up to 22.6 mg/l under anoxic conditions has no significant effect on the SMP formation. With a consideration of SMP formation under anoxic conditions, an ASM3-based denitrification model is developed. The results show that the developed model is able to capture the relationship between the SMP formation and the substrate consumption by activated sludge in the denitrification process.

In developing countries, there is controversy over the correct perception regarding environmental and developmental issues. Few studies have examined the perception of low-income nationals in regards to social and environmental issues. This paper looks at the relationship between socio-demographic factors and the groups’ perceived priority regarding environmental and social issues in Wujin County. The results indicated that most residents, specifically the young, government employed and the urban community consider environmental issues to be serious, especially in relation to air pollution and water pollution. Furthermore, many residents feel it is important to rank environmental problems that are related to other social and economic issues, and that environmental protection must be set as a priority in Wujin County. Compared to social issues, environmental concern was greater among the young, government employed, and the urban community, because of their higher education and affluence. In addition, 66.2% of residents consider environmental protection to be more important than economic development. Thus, environmental protection must be set as a high priority in Wujin County, in order to face the many social and environmental challenges inherent in development.

A questionnaire survey of residents’ risk perceptions related to Taiwan nuclear power plant in China was carried out to explore the determining factors that affect individual risk perception. This study proposed to pursue a more comprehensive understanding of factors that affected individual risk perception to nuclear power plants. Covariance structure analysis was conducted using risk perceptions of nuclear power as dependent variable and including interest and knowledge levels of nuclear power, acceptability, benefit perception, trust in nuclear power operation, and trust in government as independent variables. The use of the hypothesis of Elaboration likelihood model (ELM) was also proposed. The results showed that persons with higher levels of interest and knowledge of nuclear power had their own perceptions of risk closely associated with acceptability and potential benefits of nuclear power. In contrast, persons with no interest in and knowledge of nuclear power would have risk perceptions related to their trust in nuclear operation and the government, which partially supported the ELM hypothesis. All these results indicated that the government in China plays an important role in rational risk perceptions, and well-designed communication of risks will help the public to be involved in risk management and improve people’s rational acceptance of risk.

Small- and medium-sized enterprises (SMEs) play an important role in sustainable development not only for their significant contribution to China’s economy, but also for their large share of total discharged pollutants. Therefore, this research takes the enterprises in Suzhou Industrial Park, China as the case study to investigate the environmental management practices of SMEs, and identify drivers and barriers to engaging businesses in environmental management initiatives. It is shown that, as in other countries, SMEs are less active in adopting environmental management initiatives than larger companies. Legislation remains the key driver to engage SMEs in environmental management initiatives. Based on the analysis, policy recommendations are also presented.

In order to evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization with intravenous real-time myocardial contrast echocardiography (RT-MCE), intravenous RT-MCE was performed on 20 patients with myocardial infarction before coronary revascularization. Follow-up echocardiography was performed 3 months after coronary revascularization. Segmental wall motion was assessed using 18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions: homogeneous opacification=1; partial or reduced opacification or subendocardial contrast defect=2; contrast defect=3. Myocardial perfusion score index (MPSI) was calculated by dividing the total sum of contrast score by the total number of segments with abnormal wall motion. Twenty patients were classified into 2 groups according to the MPSI: MPSIor=1.5 as good myocardial perfusion, MPSI1.5 as poor myocardial perfusion. To assess the left ventricular remodeling, the following comparisons were carried out: (1) Comparisons of left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) before and 3 months after revascularization in two groups; (2) Comparisons of LVEF, LVESV and LVEDV pre-revascularization between two groups and comparisons of these 3 months post-revascularization between two groups; (3) Comparisons of the differences in LVEF, LVESV and LVEDV between 3 months post-and pre-revascularization (DeltaLVEF, DeltaLVESV and DeltaLVEDV) between two groups; (4) The linear regression analysis between DeltaLVEF, DeltaLVESV, DeltaLVEDV and MPSI. The results showed that the LVEF obtained 3 months after revascularization in patients with MPSI1.5 was obviously lower than that in those with MPSIor=1.5. The LVEDV obtained 3 months post-revascularization in patients with MPSI1.5 was obviously larger than that in those with MPSIor=1.5 (P=0.002 and 0.04). The differences in DeltaLVEF and DeltaLVEDV between patients with MPSI1.5 and those with MPSIor=1.5 were significant (P=0.002 and 0.001, respectively). Linear regression analysis revealed that MPSI had a negative correlation with DeltaLVEF and a positive correlation with DeltaLVESV, DeltaLVEDV (P=0.004, 0.008, and 0.016, respectively). It was concluded that RT-MCE could accurately evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization.

The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows. In this study, we used the material flow analysis (MFA) to model the material input and output of the Wujin District of Changzhou City, Jiangsu Province in China. It was revealed that: (1) total material input and material input per capita increased with economic development, while the total material output and material output per capita decreased consistently; (2) except for water, the total material input continued to increase. Input of solid materials grew faster than that of gaseous materials, while the total material output declined. The gas output accounted for the largest proportion of the output resulting in primary environmental pollution as burned fossil fuel; (3) water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita. The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential wastewater discharge followed by industrial wastewater discharge; (4) material input per unit GDP fluctuated and material output per unit GDP decreased. A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed. These results suggest that the efficiency of resource use in the Wujin District has improved. This weakened the direct link between economic development and environmental deterioration. Additionally, we discussed the harmonic development between environment and economy. Potential limitations of MFA’s application were also discussed. It is suggested that effective measures should be taken for the enforcement of circular economic strategies and the construction of a resource-saving economy

During the transition from IPv4 to IPv6, the IPv6 islands inside the IPv4 networks need to communicate with each other and with the native IPv6 network. The drawback of existing IPv6 transition methods is that relay gateways become potential communication bottlenecks. In this paper, a new method--PS64--is presented to connect IPv6 islands together over IPv4 network and reduce the reliance on these relays by shifting the burden to edge gateways on each island. In this method, direct tunnels are set up between the IPv6 islands, and a P2P network is maintained between edge gateways of these islands to propagate information of tunnel end points. After describing the algorithm, we analyze the connectivity of the P2P network, the scalability of this algorithm, and present the prototype and experiments. The results of our analysis and experiments show that the proposed method is reliable, scalable and effective. Obviously, this technique works for all IPvX over IPvY situations.

The CACTUS experiment recently observed a gamma ray excess above 50 GeV from the direction of the Draco dwarf spheroidal galaxy. Considering that Draco is dark matter dominated the gamma rays may be generated through dark matter annihilation in the Draco halo. In the framework of the minimal supersymmetric extension of the standard model we explore the parameter space to account for the gamma ray signals at CACTUS. We find that the neutralino mass is constrained to be approximately in the range between 100 GeV ~ 400 GeV and a sharp central cuspy of the dark halo profile in Draco is necessary to explain the CACTUS results. We then discuss further constraints on the supersymmetric parameter space by observations at the ground based ARGO detector. It is found that the parameter space can be strongly constrained by ARGO if no excess from Draco is observed above 100 GeV., 15 pages, 4 figures

According to our recent studies on the nonequilibrium solvation, the solvent reorganization energy λ s is found to be the cost of maintaining the residual polarization, which equilibrates with the constraining extra electric fi eld. In this work, a matrix form of λ s has been formulated based our new analytical expression of the solvent reorganization energy. By means of the integral equation formulation- polarizable continuum model ( IEF - PCM ), a new numerical algorithm for λ s has been implemented as a subroutine coupled with the Q- Chem package. Then, we have performed a comparison of numerical results with analytical solution obtained by two-sphere model for λ s in selfexchange electron transfer (ET) reaction of He–He+ system. The numerical results and analytical solution coincide as the distance between the donor and the acceptor. In order to compare with our pervious numerical algorithm with dielectric polarizable continuum model, self-exchange ET reactions between tetracyanoethylene, tetrathiafulvalene , and their corresponding ionic radicals in acetonitrile have been studied. Overall, the solvent reorganization energy calculated by IEF - PCM is more reasonable since IEF - PCM gives a better self-energy of surface element.

This study was designed to explore the influence of intra-operative perforation on prognosis of low rectal cancer after APR and to investigate the risk factors of perforation. Perforation is not scarce during the procedure of abdominoperineal resection (APR). There is no consensus on perforation rate and related risk factor for APR. Data of 925 patients who received APR for low rectal cancer between January 2000 and August 2008 were reviewed. The intra-operative perforation rate was 7.4 % (68/925). The recurrence rate was 28.6 % in patients with intra-operative perforation compared with 6.8 % in patients with no perforation (P < 0.001); 5-year survival rate in patients with perforation was 41.4 and 66.3 % in patients with no perforation. Univariate analysis showed that intra-operative perforation affected recurrence rate and survival significantly (P < 0.001, P < 0.001); multivariate analysis revealed that intra-operative perforation was an independent prognostic factors for recurrence (RR: 3.087, P < 0.001), while not for survival (RR: 1.331, P = 0.051). Patients aged more than 70 years, T3 tumor and treated by general surgeon had higher perforation rate (P = 0.001, P = 0.004, P = 0.008). Intra-operative perforation affected the prognosis of low rectal cancer after APR significantly. Elderly patient aged more than 70 years, T3 tumor and general surgeon who performed operation were three risk factors of increased perforation rate.

We calculate the CP-violating effects in the top quark semi-leptonic three body decays induced by the supersymmetric CP-odd phase of the top squark trilinear soft breaking term $\arg(A_t)$. The light top squark mass is assumed to be close to the top quark mass $m_{\tilde{t}}\sim m_t$. The CP-conserving phase is provided by the $\chi^+$ and $\chi^0$ cut. We find that the partial rate asymmetry is in the 0.1% level. In the most favorable parameter region the decay rate asymmetr can reach up to 0.55%., Comment: 18 pages, 12 eps figures