1,667 research outputs found

    Incentives for food waste diversion:Exploration of a long term successful Chinese city residential scheme

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    There are no academic studies of incentives schemes for household recycling which are successful or useful on large scales in the longer term. For food waste sorting very few successful schemes have been reported, with or without incentives. Here the authors report findings about a two-year old, 23,000-household scheme in Nanjing, China, from an exploratory case study designed to identify key factors using observations, measurements, company data and interviews. Results indicate that residents were initially motivated by the incentives (e.g. points exchanged for eggs) and social influences, but habit was the key factor for maintaining their behaviour, and cited as the main reason they would continue if the incentives stopped. Interestingly, a perceived improvement in the community site’s cleanliness was also cited as an ongoing motivation, and social influences was not mentioned. The perceived success of the scheme was confirmed via measurements of participation rates (32%), the weight of food waste diverted (0.62kg per household), and estimates of the contamination rate (<1%) and food capture rate (30%) 22 months after start. This work identifies key factors for further studies of positive incentives as habit (and thus duration), site cleanliness, and variation in ranking with time of social norms

    Anemia Prevalence among Pregnant Women and Birth Weight in Five Areas in China

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    Objectives: To investigate the current prevalence of anemia among pregnant women in different areas of China and the association with birth weight and educational level. Methods: A total of 6,413 women aged 24-37 in the third trimester of pregnancy from five areas were randomly selected from all gravidas who gave birth in the hospitals from 1999 to 2003. Blood hemoglobin concentration (Hb) was measured by the cyanomethemoglobin method; Hb <110 g/l was considered as anemia. Results: The overall prevalence of anemia was 58.6%, ranging from 48.1 to 70.5% in the five areas. There was a significant difference in the prevalence of anemia between women who have mental jobs and those who have physical jobs (52.3 vs. 61.1%, p <0.01). The prevalence of anemia depended on the level of education: with 52.9, 62.4 and 66.5%, for college, secondary school and primary education, respectively, and the difference was statistically significant (p = 0.005). Results showed that higher birth weight was associated with Hb concentrations ranging from 90 to 140 g/l, whereas lower birth weight occurred below 80 g/l and above 140 g/l Hb. Conclusions: The prevalence of anemia in Chinese pregnant women was high both in rural areas and towns. Area of residence, education level and type of job influenced the prevalence of anemia. Low maternal Hb concentrations influenced birth weight

    Role of inertia in two-dimensional deformation and breakup of a droplet

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    We investigate by Lattice Boltzmann methods the effect of inertia on the deformation and break-up of a two-dimensional fluid droplet surrounded by fluid of equal viscosity (in a confined geometry) whose shear rate is increased very slowly. We give evidence that in two dimensions inertia is {\em necessary} for break-up, so that at zero Reynolds number the droplet deforms indefinitely without breaking. We identify two different routes to breakup via two-lobed and three-lobed structures respectively, and give evidence for a sharp transition between these routes as parameters are varied.Comment: 4 pages, 4 figure

    kTk_T factorization of exclusive processes

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    We prove kTk_T factorization theorem in perturbative QCD (PQCD) for exclusive processes by considering πγγ(π)\pi\gamma^*\to \gamma(\pi) and Bγ(π)lνˉB\to\gamma(\pi) l\bar\nu. The relevant form factors are expressed as the convolution of hard amplitudes with two-parton meson wave functions in the impact parameter bb space, bb being conjugate to the parton transverse momenta kTk_T. The point is that on-shell valence partons carry longitudinal momenta initially, and acquire kTk_T through collinear gluon exchanges. The bb-dependent two-parton wave functions with an appropriate path for the Wilson links are gauge-invariant. The hard amplitudes, defined as the difference between the parton-level diagrams of on-shell external particles and their collinear approximation, are also gauge-invariant. We compare the predictions for two-body nonleptonic BB meson decays derived from kTk_T factorization (the PQCD approach) and from collinear factorization (the QCD factorization approach).Comment: 11 pages, REVTEX, 5 figure

    Detection of eight different tospovirus species by a monoclonal antibody against the common epitope of NSs protein

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    Rabbit antisera against the nucleocapsid protein (NP) have been commonly used for detection of tospoviruses and classification into serogroups or serotypes. Mouse monoclonal antibodies (MAbs) with high specificity to the NPs have also been widely used to identify tospovirus species. Recently, a serogroup-specific MAb against the NSs protein of Watermelon silver mottle virus (WSMoV) was produced by our laboratory to react with five members of WSMoV serogroup, i.e., WSMoV, Capsicum chlorosis virus (CaCV), Calla lily chlorotic spot virus (CCSV), Peanut bud necrosis virus (PBNV) and Watermelon bud necrosis virus (WBNV). The epitope recognized by the NSs MAb was determined and the comparison with the reported sequences of tospoviral NSs proteins revealed that the epitope is highly conserved at the N-terminal region of NSs proteins among members of WSMoV and Iris yellow spot virus (IYSV) serogroups, and Melon yellow spot virus (MYSV) serotype. When the NSs MAb was further used to react with the crude antigens of MYSV serotype, IYSV and Tomato yellow ring virus (TYRV) of IYSV serogroup, strong serological reactions, both in ELISA and western blotting, were observed. Thus, our results indicated that the NSs MAb is a useful and convenient tool for detection of the eight tospovirus species. It is also suggested that these eight Asian-type tospoviruses, i.e., WSMoV, CaCV, CCSV, PBNV, WBNV, MYSV, IYSV and TYRV, may share a common evolutionary ancesto

    Threshold resummation for exclusive B meson decays

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    We argue that double logarithmic corrections αsln2x\alpha_s\ln^2 x need to be resumed in perturbative QCD factorization theorem for exclusive BB meson decays, when the end-point region with a momentum fraction x0x\to 0 is important. These double logarithms, being of the collinear origin, are absorbed into a quark jet function, which is defined by a matrix element of a quark field attached by a Wilson line. The factorization of the jet function from the decay BγlνˉB\to\gamma l\bar\nu is proved to all orders. Threshold resummation for the jet function leads to a universal, {\it i.e.}, process-independent, Sudakov factor, whose qualitative behavior is analyzed and found to smear the end-point singularities in heavy-to-light transition form factors.Comment: 10 pages, more details are include

    Sharp constants in weighted trace inequalities on Riemannian manifolds

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    We establish some sharp weighted trace inequalities W^{1,2}(\rho^{1-2\sigma}, M)\hookrightarrow L^{\frac{2n}{n-2\sigma}}(\pa M) on n+1n+1 dimensional compact smooth manifolds with smooth boundaries, where ρ\rho is a defining function of MM and σ(0,1)\sigma\in (0,1). This is stimulated by some recent work on fractional (conformal) Laplacians and related problems in conformal geometry, and also motivated by a conjecture of Aubin.Comment: 34 page

    Perturbative QCD analysis of BϕKB \to \phi K^* decays

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    We study the first observed charmless BVVB\to VV modes, the BϕKB\to\phi K^* decays, in perturbative QCD formalism. The obtained branching ratios B(BϕK)15×106B(B\to\phi K^*)\sim 15 \times 10^{-6} are larger than 9×106\sim 9\times 10^{-6} from QCD factorization. The comparison of the predicted magnitudes and phases of the different helicity amplitudes, and branching ratios with experimental data can test the power counting rules, the evaluation of annihilation contributions, and the mechanism of dynamical penguin enhancement in perturbative QCD, respectively.Comment: 14 pages, 2 tables, brief disscussion on hard sacle added, version to appear in PR
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