291 research outputs found

    A dynamic and continuous allowances allocation methodology for the prevention of carbon leakage: Emission control coefficients

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    © 2018 Elsevier Ltd Carbon leakage has become the core issue of emission trading systems. Using data from Hubei Province, this paper identifies the drawbacks of the prevailing methods for preventing carbon leakage and proposes a new methodology to overcome them, namely, Emission Control Coefficients. In contrast to the common tiered structure method, the Emission Control Coefficients generate a dynamic and continuous emission control coefficient for each industry which will improve the effectiveness and fairness of allowance allocation, set aside sufficient time for the low carbon transformation of industries, and balance the needs to protect competitiveness and decarbonize and are particularly suitable for the emission trading systems of developing counties. This paper makes three main academic contributions: Firstly, it proposes a new indicator, the abatement potential for more effective determining allowance allocation than the prevailing method. Secondly, it better distinguishes industrial differences. Thirdly, it can better respond to the problem of excess allowances that is due to technological advances and trade pattern changes

    Examination of Parental Effect on the Progeny Diapause by Reciprocal Cross Test in the Cabbage Beetle, Colaphellus bowringi

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    The cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae), a serious pest of crucifers in China, undergoes summer or winter diapause in the soil as an adult. In the present study, the incidence of diapause were measured in reciprocal crosses between a high—diapause strain (HD strain) and a laboratory—selected nondiapausing strain (ND strain) under different photoperiods and temperatures, to explore parental influences on the progeny diapause. Sensitivity to photoperiod in the selected nondiapausing strain was nearly eliminated at 25 °C, whereas sensitivity to temperature of the selected nondiapausing strain was retained under continuous darkness at 20 and 22 °C. Reciprocal crosses between the HD strain and the ND strain showed that the incidence of diapause in the progeny was always intermediate to that of the parents under different photoperiods and temperatures, suggesting that diapause induction was determined by both female and male parents. There was a significant effect of temperature; temperature interacted with reciprocal cross on diapause induction, whereas no significant effect of reciprocal cross was demonstrated. The incidence of diapause in ♀ND × ♂HD was the same as in ♀HD × ♂ND under continuous darkness at 18 °C (100%) and 26 °C (0%), but the former was higher than that in ♀HD × ♂ND under continuous darkness at 22 °C, suggesting that female parent does not exhibit strong influence on the diapause response to temperature. There was a significant effect of photoperiod and reciprocal cross on diapause induction, whereas no significant interactive effect on diapause induction was demonstrated. Incidence of diapause in ♀HD × ♂ND was always higher than in ♀ND × ♂HD at 25 °C and 12:12 L:D, 14:10 L:D, and 16:8 L:D, suggesting a strong maternal influence on the diapause response to photoperiod, though a significant difference was observed only at 14:10 L:D. Our results support the idea that diapause induction is determined by both female and male parents. However, results also indicated that a strong maternal influence on diapause was exhibited only in response to photoperiod

    Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.

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    BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψ′→π+π−J/ψ(J/ψ→γppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ′\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=1861−13+6(stat)−26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

    Vector-Virus Mutualism Accelerates Population Increase of an Invasive Whitefly

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    The relationships between plant viruses, their herbivore vectors and host plants can be beneficial, neutral, or antagonistic, depending on the species involved. This variation in relationships may affect the process of biological invasion and the displacement of indigenous species by invaders when the invasive and indigenous organisms occur with niche overlap but differ in the interactions. The notorious invasive B biotype of the whitefly complex Bemisia tabaci entered China in the late 1990s and is now the predominant or only biotype in many regions of the country. Tobacco curly shoot virus (TbCSV) and Tomato yellow leaf curl China virus (TYLCCNV) are two whitefly-transmitted begomoviruses that have become widespread recently in south China. We compared the performance of the invasive B and indigenous ZHJ1 whitefly biotypes on healthy, TbCSV-infected and TYLCCNV-infected tobacco plants. Compared to its performance on healthy plants, the invasive B biotype increased its fecundity and longevity by 12 and 6 fold when feeding on TbCSV-infected plants, and by 18 and 7 fold when feeding on TYLCCNV-infected plants. Population density of the B biotype on TbCSV- and TYLCCNV-infected plants reached 2 and 13 times that on healthy plants respectively in 56 days. In contrast, the indigenous ZHJ1 performed similarly on healthy and virus-infected plants. Virus-infection status of the whiteflies per se of both biotypes showed limited effects on performance of vectors on cotton, a nonhost plant of the viruses. The indirect mutualism between the B biotype whitefly and these viruses via their host plants, and the apparent lack of such mutualism for the indigenous whitefly, may contribute to the ability of the B whitefly biotype to invade, the displacement of indigenous whiteflies, and the disease pandemics of the viruses associated with this vector
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