Ozone production in four major cities of China: sensitivity to ozone precursors and heterogeneous processes

Abstract. Despite a large volume of research over a number of years, our understandings of the key precursors that control tropospheric ozone production and the impacts of heterogeneous processes remain incomplete. In this study, we analyze measurements of ozone and its precursors made at rural/suburban sites downwind of four large Chinese cities – Beijing, Shanghai, Guangzhou and Lanzhou. At each site the same measurement techniques were utilized and a photochemical box model based on the Master Chemical Mechanism (v3.2) was applied, to minimize uncertainties in comparison of the results due to differences in methodology. All four cities suffered from severe ozone pollution. At the rural site of Beijing, export of the well-processed urban plumes contributed to the extremely high ozone levels (up to an hourly value of 286 ppbv), while the pollution observed at the suburban sites of Shanghai, Guangzhou and Lanzhou was characterized by intense in-situ ozone production. The major anthropogenic hydrocarbons were alkenes and aromatics in Beijing and Shanghai, aromatics in Guangzhou, and alkenes in Lanzhou. The ozone production was found to be in a VOCs-limited regime in both Shanghai and Guangzhou, and a mixed regime in Lanzhou. In Shanghai, the ozone formation was most sensitive to aromatics and alkenes, while in Guangzhou aromatics were the predominant ozone precursors. In Lanzhou, either controlling NOx or reducing emissions of olefins from the petrochemical industry would mitigate the local ozone production. The potential impacts of several heterogeneous processes on the ozone formation were assessed. The hydrolysis of dinitrogen pentoxide (N2O5), uptake of the hydroperoxyl radical (HO2) on particles, and surface reactions of NO2 forming nitrous acid (HONO) present considerable sources of uncertainty in the current studies of ozone chemistry. Further efforts are urgently required to better understand these processes and refine atmospheric models

Factors related to children's caries: a structural equation modeling approach

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An integrated particle sampler and lung radiation dosimeter

A lung dosimeter that can record the nonradiological hazard of aerosol particles to the lung as well as the radiological hazard of air borne radionuclides that are attached to aerosol particles has been developed. The dosimeter is capable of recording aerosol particles of diameters from 10-2 μm to 102 μ by electrostatic collection in a specially designed dosimeter body. The aerosol size distribution is recorded on a mylar strip and the activity size distribution of α, β, and γ radiation emitting aerosols recorded on another strip coated with α-Al2O3:C. Both strips can be read by a specially built reader, the output of which can be used to calculate the nonradiological hazard and radiological hazard, respectively, and to give an overall picture of the exposure.published_or_final_versio

Rapid mixing of viscous liquids by electrical coiling

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The US stock market leads the Federal funds rate and Treasury bond yields

Using a recently introduced method to quantify the time varying lead-lag dependencies between pairs of economic time series (the thermal optimal path method), we test two fundamental tenets of the theory of fixed income: (i) the stock market variations and the yield changes should be anti-correlated; (ii) the change in central bank rates, as a proxy of the monetary policy of the central bank, should be a predictor of the future stock market direction. Using both monthly and weekly data, we found very similar lead-lag dependence between the S&P500 stock market index and the yields of bonds inside two groups: bond yields of short-term maturities (Federal funds rate (FFR), 3M, 6M, 1Y, 2Y, and 3Y) and bond yields of long-term maturities (5Y, 7Y, 10Y, and 20Y). In all cases, we observe the opposite of (i) and (ii). First, the stock market and yields move in the same direction. Second, the stock market leads the yields, including and especially the FFR. Moreover, we find that the short-term yields in the first group lead the long-term yields in the second group before the financial crisis that started mid-2007 and the inverse relationship holds afterwards. These results suggest that the Federal Reserve is increasingly mindful of the stock market behavior, seen at key to the recovery and health of the economy. Long-term investors seem also to have been more reactive and mindful of the signals provided by the financial stock markets than the Federal Reserve itself after the start of the financial crisis. The lead of the S&P500 stock market index over the bond yields of all maturities is confirmed by the traditional lagged cross-correlation analysis.Comment: 12 pages, 7 figures, 1 tabl

Life course approach in assessment of ECC in 2-year-old children

Oral Session A - Cariology Research & Instruments and Equipmentpublished_or_final_versionThe 2nd Meeting of the International Association for Dental Research (IADR) Pan Asian Pacific Federation (PAPF) and the 1st Meeting of the International Association for Dental Research (IADR) Asia/Pacific Region (APR), Wuhan, China, 22-24 September 2009. In Journal of Dental Research, 2009, v. 88, special issue B, abstract no.

Pandemic A/H1N1 2009 Influenza Virus-like Particles Elicited Higher and Broader Immune Responses than the Commercial Panenza Vaccine

Objectives: The aim was to construct 2009 pandemic A/H1N1 influenza VLPs (virus-like particles) and compare the immunogenicity and protection efficacy with the commercial Panenza vaccine in BALB/c mouse model. Methods: VLPs derived from influenza A/Hong Kong/01/2009 (H1N1) virus were constructed by Bac-to-Bac baculovirus expression system. VLPs were purified by sucrose density gradient ultracentrifugation and then characterized by Western blotting analysis and transmission electron microscopy. After single dose vaccination with 3 µg of VLPs and equal amount of Panenza vaccine, the immune responses and efficacy of protection induced by VLPs were compared with those elicited by the Panenza vaccine in 6-8 week female BALB/c mice. Key findings: VLPs could induce higher antibody titer as determined by hemagglutinin inhibition and microneutralization assay. Furthermore, we demonstrated that VLPs induced better antibody response to neuraminidase. In addition, VLP vaccinated mice had stronger cell-mediated immune response. As a result, our VLPs conferred 100% protection while the Panenza vaccine only conferred 67% protection. Conclusion: From the results, we concluded that influenza VLPs are highly immunogenic and they are promising to be developed as an alternative strategy to vaccine production in order to control the spread of influenza viruses.published_or_final_versio

Intelligent Financial Fraud Detection Practices: An Investigation

Financial fraud is an issue with far reaching consequences in the finance industry, government, corporate sectors, and for ordinary consumers. Increasing dependence on new technologies such as cloud and mobile computing in recent years has compounded the problem. Traditional methods of detection involve extensive use of auditing, where a trained individual manually observes reports or transactions in an attempt to discover fraudulent behaviour. This method is not only time consuming, expensive and inaccurate, but in the age of big data it is also impractical. Not surprisingly, financial institutions have turned to automated processes using statistical and computational methods. This paper presents a comprehensive investigation on financial fraud detection practices using such data mining methods, with a particular focus on computational intelligence-based techniques. Classification of the practices based on key aspects such as detection algorithm used, fraud type investigated, and success rate have been covered. Issues and challenges associated with the current practices and potential future direction of research have also been identified.Comment: Proceedings of the 10th International Conference on Security and Privacy in Communication Networks (SecureComm 2014

Genome-Wide Characterization of Menin-Dependent H3K4me3 Reveals a Specific Role for Menin in the Regulation of Genes Implicated in MEN1-Like Tumors

Inactivating mutations in the MEN1 gene predisposing to the multiple endocrine neoplasia type 1 (MEN1) syndrome can also cause sporadic pancreatic endocrine tumors. MEN1 encodes menin, a subunit of MLL1/MLL2-containing histone methyltransferase complexes that trimethylate histone H3 at lysine 4 (H3K4me3). The importance of menin-dependent H3K4me3 in normal and transformed pancreatic endocrine cells is unclear. To study the role of menin-dependent H3K4me3, we performed in vitro differentiation of wild-type as well as menin-null mouse embryonic stem cells (mESCs) into pancreatic islet-like endocrine cells (PILECs). Gene expression analysis and genome-wide H3K4me3 ChIP-Seq profiling in wild-type and menin-null mESCs and PILECs revealed menin-dependent H3K4me3 at the imprinted Dlk1-Meg3 locus in mESCs, and all four Hox loci in differentiated PILECs. Specific and significant loss of H3K4me3 and gene expression was observed for genes within the imprinted Dlk1-Meg3 locus in menin-null mESCs and the Hox loci in menin-null PILECs. Given that the reduced expression of genes within the DLK1-MEG3 locus and the HOX loci is associated with MEN1-like sporadic tumors, our data suggests a possible role for menin-dependent H3K4me3 at these genes in the initiation and progression of sporadic pancreatic endocrine tumors. Furthermore, our investigation also demonstrates that menin-null mESCs can be differentiated in vitro into islet-like endocrine cells, underscoring the utility of menin-null mESC-derived specialized cell types for genome-wide high-throughput studies