4,726 research outputs found

    Alcohol Use, Abuse, and Dependency in Shanghai

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    The use of alcohol for social and ceremonial occasions was recorded in Chinese history as early as 1760 B.C. during the Yin Dynasty (Ci-Hai Encyclopedia, 1979:936). The cultural tradition of ancient China placed alcoholic beverages at the center of social occasions, which presumably was the origin of the adage: Without wine, there is no li (or etiquette). Thus, the use of alcoholic beverages has always been accompanied by the concept of propriety and the discharging of one\u27s role obligations m social functions, rather than that of personal indulgence

    Neutrino mixing in matter

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    Three-neutrino mixing in matter is studied through a set of evolution equations which are based on a rephasing invariant parametrization. Making use of the known properties of measured neutrino parameters, analytic, approximate, solutions are obtained. Their accuracy is confirmed by comparison with numerical integration of these equations. The results, when expressed in the elements squared of the mixing matrix, exhibit striking patterns as the matter density varies.Comment: Revised, 5 pages, 3 figures, references added

    Doping Dependence of the Magnetic Resonance Peak in YBa_2 Cu_3 O_{6+x}

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    We report inelastic neutron scattering experiments on the doping dependence of the energy and spectral weight of the sharp magnetic resonance peak in YBa_2 Cu_3 O_{6+x}. These measurements also shed light on the relationship between the magnetic excitations in the normal and superconducting states.Comment: (mostly corrections to figures and minor change to caption in Fig.5) 5 figures. It will be published in the proceedings of M2S-HTSC-V. It needs the elsevier style file (not included) to convert to postscrip

    Theory of Coherent cc-Axis Josephson Tunneling between Layered Superconductors

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    We calculate exactly the Josephson current for cc-axis coherent tunneling between two layered superconductors, each with internal coherent tight-binding intra- and interlayer quasiparticle dispersions. Our results also apply when one or both of the superconductors is a bulk material, and include the usually neglected effects of surface states. For weak tunneling, our results reduce to our previous results derived using the tunneling Hamiltonian. Our results are also correct for strong tunneling. However, the cc-axis tunneling results of Tanaka and Kashiwaya are shown to be incorrect in any limit. In addition, we consider the cc-axis coherent critical current between two identical layered superconductors twisted an angle ϕ0\phi_0 about the cc-axis with respect to each other. Regardless of the order parameter symmetry, our coherent tunneling results using a tight-binding intralayer quasiparticle dispersion are inconsistent with the recent cc-axis twist bicrystal Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} twist junction experiments of Li {\it et al.}Comment: 11 pages, 13 figures, submitted to Physical Review

    Limiting shapes for deterministic centrally seeded growth models

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    We study the rotor router model and two deterministic sandpile models. For the rotor router model in Zd\mathbb{Z}^d, Levine and Peres proved that the limiting shape of the growth cluster is a sphere. For the other two models, only bounds in dimension 2 are known. A unified approach for these models with a new parameter hh (the initial number of particles at each site), allows to prove a number of new limiting shape results in any dimension d1d \geq 1. For the rotor router model, the limiting shape is a sphere for all values of hh. For one of the sandpile models, and h=2d2h=2d-2 (the maximal value), the limiting shape is a cube. For both sandpile models, the limiting shape is a sphere in the limit hh \to -\infty. Finally, we prove that the rotor router shape contains a diamond.Comment: 18 pages, 3 figures, some errors corrected and more explanation added, to appear in Journal of Statistical Physic

    Quantitative evaluation of motor function before and after engraftment of dopaminergic neurons in a rat model of Parkinson's disease

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    Although gait change is considered a useful indicator of severity in animal models of Parkinson's disease, systematic and extensive gait analysis in animal models of neurological deficits is not well established. The CatWalk-assisted automated gait analysis system provides a comprehensive way to assess a number of dynamic and static gait parameters simultaneously. In this study, we used the Catwalk system to investigate changes in gait parameters in adult rats with unilateral 6-OHDA-induced lesions and the rescue effect of dopaminergic neuron transplantation on gait function. Four weeks after 6-OHDA injection, the intensity and maximal area of contact were significantly decreased in the affected paws and the swing speed significantly decreased in all four paws. The relative distance between the hind paws also increased, suggesting that animals with unilateral 6-OHDA-induced lesions required all four paws to compensate for loss of balance function. At 8 weeks post-transplantation, engrafted dopaminergic neurons expressed tyrosine hydroxylase. In addition, the intensity, contact area, and swing speed of the four limbs increased and the distance between the hind paws decreased. Partial recovery of methamphetamine-induced rotational response was also noted

    Development of a machine vision system for weed detection during both of off-season and in-season in broadacre no-tillage cropping lands

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    More than half of the Australian cropping land is no-tillage and weed control within continuous no-tillage agricultural cropping area is becoming more and more difficult. A major problem is that the heavy herbicide usage causes some of more prolific weeds becoming more resistant to the regular herbicides and therefore more powerful and more expensive options are being pursued. To overcome such problems with aiming at the reduction of herbicide usage, this proposed research focuses on developing a machine vision system which can detect and mapping weeds or do spot spray. The weed detection methods described in this study include three aspects which are image acquisition, a new green plant detection algorithm using hybrid spectral indices and a new inter-row weed detection method taking the advantage of the location of the crop rows. The developed method could detect the weeds both during the non-growing summer period and also within the growing season until the canopy of the crop has closed. The design of the methods focuses on overcoming the challenges of the complex no-tillage background, the faster image acquisition speed and quicker processing time for real-time spot spray. The experiment results show that the proposed method are more suitable for the weed detection in the no-tillage background than the existing methods and could be used as a powerful tool for the weed control.Huajian Liu, Sang Heng Lee and Chris Saunder

    Capturing a c2 daisy chain using the threading-followed-by-swelling approach

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    We have used the "threading-followed-by-swelling'' approach to fix a daisy chain structure in solution, leading to the isolation of a captured [c2] daisy chain in 77% yield

    The molecular systems composed of the charmed mesons in the HSˉ+h.c.H\bar{S}+h.c. doublet

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    We study the possible heavy molecular states composed of a pair of charm mesons in the H and S doublets. Since the P-wave charm-strange mesons Ds0(2317)D_{s0}(2317) and Ds1(2460)D_{s1}(2460) are extremely narrow, the future experimental observation of the possible heavy molecular states composed of Ds/DsD_s/D_s^\ast and Ds0(2317)/Ds1(2460)D_{s0}(2317)/D_{s1}(2460) may be feasible if they really exist. Especially the possible JPC=1J^{PC}=1^{--} states may be searched for via the initial state radiation technique.Comment: 42 pages, 4 tables, 31 figures. Improved numerical results and Corrected typos
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