548 research outputs found

    Obesity prevalence and time trend among youngsters in China, 1982-2002

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    Purpose of present study is to describe the prevalence and trend of overweight and obesity, as well as its coexistence with stunting, among youngsters in China, from 1982 to 2002. Data from children 7-17 years of age from three cross-sectional national surveys: 1982 China National Nutrition Survey (5 334 boys and 4 793 girls), 1992 China National Nutrition Survey (8 048 boys and 7 453 girls) and 2002 China National Nutrition and Health Survey (23 242 boys and 21 638 girls) were used in this study. Overweight and obesity were defined according to age, sex specific BMI cut-off points from the International Obesity Task Force, while stunting was defined as height-for-age below -2 standard deviation from the NCHS/WHO reference median value. Results: Overweight prevalence of Chinese youngsters was 1.2%, 3.7% and 4.4%, while the obesity prevalence was 0.2%, 0.9% and 0.9% in 1982, 1992 and 2002, respectively. Both the overweight and obesity prevalence and their increment were higher among boys in urban areas. In 1982, 28.4% of overweight and 69.6% of obese youngsters were stunted, this decreased to 22.0% and 46.4% in 1992, and then to 5.7% and 7.7% in 2002, respectively. Conclusion: The prevalence of overweight and obesity in Chinese youngsters were low in 1982. There has been a rapid increase since then. If this trend continues, overweight will soon reach epidemic proportions. Stunting among overweight and obese youngsters decreased dramatically at the same time

    Identification of differentially expressed genes induced by Bamboo mosaic virus infection in Nicotiana benthamiana by cDNA-amplified fragment length polymorphism

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    Background: The genes of plants can be up- or down-regulated during viral infection to influence the replication of viruses. Identification of these differentially expressed genes could shed light on the defense systems employed by plants and the mechanisms involved in the adaption of viruses to plant cells. Differential gene expression in Nicotiana benthamiana plants in response to infection with Bamboo mosaic virus (BaMV) was revealed using cDNA-amplified fragment length polymorphism (AFLP). Results: Following inoculation with BaMV, N. benthamiana displayed differential gene expression in response to the infection. Isolation, cloning, and sequencing analysis using cDNA-AFLP furnished 90 cDNA fragments with eight pairs of selective primers. Fifteen randomly selected genes were used for a combined virus-induced gene silencing (VIGS) knockdown experiment, using BaMV infection to investigate the roles played by these genes during viral infection, specifically addressing the means by which these genes influence the accumulation of BaMV protein. Nine of the 15 genes showed either a positive or a negative influence on the accumulation of BaMV protein. Six knockdown plants showed an increase in the accumulation of BaMV, suggesting that they played a role in the resistance to viral infection, while three plants showed a reduction in coat protein, indicating a positive influence on the accumulation of BaMV in plants. An interesting observation was that eight of the nine plants showing an increase in BaMV coat protein were associated with cell rescue, defense, death, aging, signal transduction, and energy production. Conclusions: This study reports an efficient and straightforward method for the identification of host genes involved in viral infection. We succeeded in establishing a cDNA-AFLP system to help track changes in gene expression patterns in N. benthamiana plants when infected with BaMV. The combination of both DNA-AFLP and VIGS methodologies made it possible to screen a large number of genes and identify those associated with infections of plant viruses. In this report, 9 of the 15 analyzed genes exhibited either a positive or a negative influence on the accumulation of BaMV in N. benthamiana plants

    Tunnelling through black rings

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    Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton gravity theory is analyzed by use of the Parikh-Wilczek tunnelling method. To get the correct tunnelling amplitude and emission rate, we adopted and developed the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronic discharge all at once, and the effect of back reaction is also taken into account. This constitute a unified approach to the tunnelling problem. Provided the first law of thermodynamics for black rings holds, the emission rate is proportional to the exponential of the change of Bekenstein-Hawking entropy. Explicit calculation for black ring temperatures agree exactly with the results obtained via the classical surface gravity method and the quasilocal formalism.Comment: 10 pages, V2: various modifications throughout the text, plus a lot of newly added reference

    The anti-caries efficacy of a dentifrice containing 1.5% arginine and 1450ppm fluoride as sodium monofluorophosphate assessed using Quantitative Light-induced Fluorescence (QLF)

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    AbstractObjectiveTo compare the efficacy of a new dentifrice containing 1.5% arginine, an insoluble calcium compound and 1450ppm fluoride to arrest and reverse naturally occurring buccal caries lesions in children relative to a positive control dentifrice containing 1450ppm fluoride alone.Study designParticipants from Chengdu, Sichuan Province, China tested three dentifrices: a new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450ppm fluoride, as sodium monofluorophosphate, a positive control dentifrice containing 1450ppm fluoride, as sodium fluoride, in a silica base, and a matched negative control dentifrice without arginine and fluoride. Quantitative Light-induced Fluorescence (QLF) was used to assess buccal caries lesions at baseline and after 3 and 6 months of product use.Results438 participants (initial age 9–13 years (mean 11.1±0.78) and 48.6% female) completed the study. No adverse events attributable to the products were reported during the course of the study. The subject mean ΔQ (mm2%), representing lesion volume, was 27.26 at baseline. After 6 months of product use, the ΔQ values for the arginine-containing, positive and negative control dentifrices were 13.46, 17.99 and 23.70 representing improvements from baseline of 50.6%, 34.0% and 13.1%. After 6 months product use, the differences between the pair wise comparisons for all three groups were statistically significant (p<0.01). The arginine-containing dentifrice demonstrated an improvement after only 3 months that was almost identical to that achieved by the conventional 1450ppm fluoride dentifrice after 6 months.ConclusionThe new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450ppm fluoride provides statistically significantly superior efficacy in arresting and reversing buccal caries lesions to a conventional dentifrice containing 1450ppm fluoride alone

    Sonic velocity in holographic fluids and its applications

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    Gravity/fluid correspondence acts as an important tool in investigating the strongly correlated fluids. We carefully investigate the holographic fluids at the finite cutoff surface by considering different boundary conditions in the scenario of gravity/fluid correspondence. We find that the sonic velocity of the boundary fluids at the finite cutoff surface is critical in clarifying the superficial similarity between the bulk viscosity and perturbation of the pressure for the holographic fluid, where we set a special boundary condition at the finite cutoff surface to explicitly express this superficial similarity. Moreover, we further take the sonic velocity into account to investigate a case with a more general boundary condition. In this more genaral case, although two parameters in the first order stress tensor of holographic fluid cannot be fixed, one can still extract the information about the transport coefficients by considering the sonic velocity seriously.Theoretical Physic

    Search for Invisible Decays of η\eta and η\eta^\prime in J/ψϕηJ/\psi \to \phi\eta and ϕη\phi \eta^\prime

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    Using a data sample of 58×10658\times 10^6 J/ψJ/\psi decays collected with the BES II detector at the BEPC, searches for invisible decays of η\eta and η\eta^\prime in J/ψJ/\psi to ϕη\phi\eta and ϕη\phi\eta^\prime are performed. The ϕ\phi signals, which are reconstructed in K+KK^+K^- final states, are used to tag the η\eta and η\eta^\prime decays. No signals are found for the invisible decays of either η\eta or η\eta^\prime, and upper limits at the 90% confidence level are determined to be 1.65×1031.65 \times 10^{-3} for the ratio B(ηinvisible)B(ηγγ)\frac{B(\eta\to \text{invisible})}{B(\eta\to\gamma\gamma)} and 6.69×1026.69\times 10^{-2} for B(ηinvisible)B(ηγγ)\frac{B(\eta^\prime\to \text{invisible})}{B(\eta^\prime\to\gamma\gamma)}. These are the first searches for η\eta and η\eta^\prime decays into invisible final states.Comment: 5 pages, 4 figures; Added references, Corrected typo

    Observation of Two New N* Peaks in J/psi -> ppinˉp pi^- \bar n and pˉπ+n\bar p\pi^+n Decays

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    The πN\pi N system in decays of J/ψNˉNπJ/\psi\to\bar NN\pi is limited to be isospin 1/2 by isospin conservation. This provides a big advantage in studying NπNN^*\to \pi N compared with πN\pi N and γN\gamma N experiments which mix isospin 1/2 and 3/2 for the πN\pi N system. Using 58 million J/ψJ/\psi decays collected with the Beijing Electron Positron Collider, more than 100 thousand J/ψpπnˉ+c.c.J/\psi \to p \pi^- \bar n + c.c. events are obtained. Besides two well known NN^* peaks at 1500 MeV and 1670 MeV, there are two new, clear NN^* peaks in the pπp\pi invariant mass spectrum around 1360 MeV and 2030 MeV. They are the first direct observation of the N(1440)N^*(1440) peak and a long-sought "missing" NN^* peak above 2 GeV in the πN\pi N invariant mass spectrum. A simple Breit-Wigner fit gives the mass and width for the N(1440)N^*(1440) peak as 1358±6±161358\pm 6 \pm 16 MeV and 179±26±50179\pm 26\pm 50 MeV, and for the new NN^* peak above 2 GeV as 2068±340+152068\pm 3^{+15}_{-40} MeV and 165±14±40165\pm 14\pm 40 MeV, respectively

    Tailoring Anderson localization by disorder correlations in 1D speckle potentials

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    We study Anderson localization of single particles in continuous, correlated, one-dimensional disordered potentials. We show that tailored correlations can completely change the energy-dependence of the localization length. By considering two suitable models of disorder, we explicitly show that disorder correlations can lead to a nonmonotonic behavior of the localization length versus energy. Numerical calculations performed within the transfer-matrix approach and analytical calculations performed within the phase formalism up to order three show excellent agreement and demonstrate the effect. We finally show how the nonmonotonic behavior of the localization length with energy can be observed using expanding ultracold-atom gases

    Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion

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    We examine the cosmological constraining power of future large-scale weak lensing surveys on the model of \emph{Euclid}, with particular reference to primordial non-Gaussianity. Our analysis considers several different estimators of the projected matter power spectrum, based on both shear and flexion, for which we review the covariances and Fisher matrices. The bounds provided by cosmic shear alone for the local bispectrum shape, marginalized over σ8\sigma_8, are at the level of ΔfNL100\Delta f_\mathrm{NL} \sim 100. We consider three additional bispectrum shapes, for which the cosmic shear constraints range from ΔfNL340\Delta f_\mathrm{NL}\sim 340 (equilateral shape) up to ΔfNL500\Delta f_\mathrm{NL}\sim 500 (orthogonal shape). The competitiveness of cosmic flexion constraints against cosmic shear ones depends on the galaxy intrinsic flexion noise, that is still virtually unconstrained. Adopting the very high value that has been occasionally used in the literature results in the flexion contribution being basically negligible with respect to the shear one, and for realistic configurations the former does not improve significantly the constraining power of the latter. Since the flexion noise decreases with decreasing scale, by extending the analysis up to max=20,000\ell_\mathrm{max} = 20,000 cosmic flexion, while being still subdominant, improves the shear constraints by 10\sim 10% when added. However on such small scales the highly non-linear clustering of matter and the impact of baryonic physics make any error estimation uncertain. By considering lower, and possibly more realistic, values of the flexion intrinsic shape noise results in flexion constraining power being a factor of 2\sim 2 better than that of shear, and the bounds on σ8\sigma_8 and fNLf_\mathrm{NL} being improved by a factor of 3\sim 3 upon their combination. (abridged)Comment: 30 pages, 4 figures, 4 tables. To appear on JCA

    Measurements of the observed cross sections for e+ee^+e^-\to exclusive light hadrons containing π0π0\pi^0\pi^0 at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV

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    By analyzing the data sets of 17.3, 6.5 and 1.0 pb1^{-1} taken, respectively, at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for e+eπ+ππ0π0e^+e^-\to \pi^+\pi^-\pi^0\pi^0, K+Kπ0π0K^+K^-\pi^0\pi^0, 2(π+ππ0)2(\pi^+\pi^-\pi^0), K+Kπ+ππ0π0K^+K^-\pi^+\pi^-\pi^0\pi^0 and 3(π+π)π0π03(\pi^+\pi^-)\pi^0\pi^0 at the three energy points. Based on these cross sections we set the upper limits on the observed cross sections and the branching fractions for ψ(3770)\psi(3770) decay into these final states at 90% C.L..Comment: 7 pages, 2 figure
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