1,701 research outputs found

    Air Passenger Duty and Outbound Tourism Demand from the United Kingdom

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    On November 1, 1994 an Air Passenger Duty (APD) was introduced in the United Kingdom, and since, this tax continues to be controversial. This article examines the effect of the ADP on UK outbound tourism demand for 10 international destinations. An autoregressive distributed lag model is developed and income, price, and tax elasticities are estimated. The income and price elasticities obtained, ranged between 0.36 and 4.11 and −0.05 and −2.02, respectively. The estimated tax elasticities suggest that the implementation of APD had a negative effect on UK outbound travel for five destinations and the demand is inelastic to changes in taxes although the magnitudes vary across destinations. The general message is that although the stated objective of APD is to reduce travel and associated carbon emissions, the effectiveness of APD, however, has been marginal; travelers are prepared to pay more in the main to maintain their demand

    A single photon produces general W state of N qubits and its application

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    Based on the Wu's scheme[1], We prepare the general N-qubit W state. We find that the concurrence of two qubits in general N-qubit W state is only related to their coefficients and we successfully apply the general N-qubit W state to quantum state transfer and quantum state prepare like that in two-qubit system

    Multiple Roles of Component Proteins in Bacterial Multicomponent Monooxygenases: Phenol Hydroxylase and Toluene/o-Xylene Monooxygenase from Pseudomonas sp. OX1.

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    Phenol hydroxylase (PH) and toluene/o-xylene monooxygenase (ToMO) from Pseudomonas sp. OX1 require three or four protein components to activate dioxygen for the oxidation of aromatic substrates at a carboxylate-bridged diiron center. In this study, we investigated the influence of the hydroxylases, regulatory proteins, and electron-transfer components of these systems on substrate (phenol; NADH) consumption and product (catechol; H(2)O(2)) generation. Single-turnover experiments revealed that only complete systems containing all three or four protein components are capable of oxidizing phenol, a major substrate for both enzymes. Under ideal conditions, the hydroxylated product yield was ∼50% of the diiron centers for both systems, suggesting that these enzymes operate by half-sites reactivity mechanisms. Single-turnover studies indicated that the PH and ToMO electron-transfer components exert regulatory effects on substrate oxidation processes taking place at the hydroxylase actives sites, most likely through allostery. Steady state NADH consumption assays showed that the regulatory proteins facilitate the electron-transfer step in the hydrocarbon oxidation cycle in the absence of phenol. Under these conditions, electron consumption is coupled to H(2)O(2) formation in a hydroxylase-dependent manner. Mechanistic implications of these results are discussed

    Predominant Coaching Leadership Behaviors of High School Head Basketball Coaches: A Pilot Study

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    Coaching leadership in sport was important because the coach-athlete relationship was considered as a crucial factor in the sport setting. Though leadership theories have been developed for a few decades, research topics related to leadership behaviors in high school settings are understudied. The purpose of the study was to examine the coaching leadership behaviors of high school head basketball coaches in Hong Kong utilizing the Leadership Scale for Sports. One hundred and twelve basketball coaches were invited to participate in the study: 56 coaches from the winning teams and another 56 coaches from the losing teams. Mixed-design 2 × 5 ANOVA indicated there was significant (p \u3c .001) main effect for the coaching behaviors. Both the top-ranking and low-ranking head basketball coaches exhibited significantly (p \u3c .001) higher level of Teaching and Instruction as well as Positive Feedback than Social Support, Democratic Behavior, and Autocratic Behavior. The mean scores as determined by the five dimensions of the LSS were in the following descending order: Positive Feedback, Training and Instruction, Social Support, Democratic Behavior, and Autocratic Behavior. The importance and application of these five coaching behaviors were discussed in detail

    SU(4) Chiral Quark Model with Configuration Mixing

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    Chiral quark model with configuration mixing and broken SU(3)\times U(1) symmetry has been extended to include the contribution from c\bar c fluctuations by considering broken SU(4) instead of SU(3). The implications of such a model have been studied for quark flavor and spin distribution functions corresponding to E866 and the NMC data. The predicted parameters regarding the charm spin distribution functions, for example, \Delta c, \frac{\Delta c}{{\Delta \Sigma}}, \frac{\Delta c}{c} as well as the charm quark distribution functions, for example, \bar c, \frac{2\bar c}{(\bar u+\bar d)}, \frac{2 \bar c}{(u+d)} and \frac{(c+ \bar c)}{\sum (q+\bar q)} are in agreement with other similar calculations. Specifically, we find \Delta c=-0.009, \frac{\Delta c}{{\Delta \Sigma}}=-0.02, \bar c=0.03 and \frac{(c+ \bar c)}{\sum (q+\bar q)}=0.02 for the \chiQM parameters a=0.1, \alpha=0.4, \beta=0.7, \zeta_{E866}=-1-2 \beta, \zeta_{NMC}=-2-2 \beta and \gamma=0.3, the latter appears due to the extension of SU(3) to SU(4).Comment: 10 RevTeX pages. Accepted for publication in Phys. Rev.

    Asymmetry of Strange Sea in Nucleons

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    Based on the finite-temperature field theory, we evaluate the medium effects in nucleon which can induce an asymmetry between quarks and antiquarks of the strange sea. The short-distance effects determined by the weak interaction can give rise to δmΔmsΔmsˉ\delta m\equiv \Delta m_s-\Delta m_{\bar s} where Δms(sˉ)\Delta m_{s(\bar s)} is the medium-induced mass of strange quark by a few KeV at most, but the long-distance effects by strong interaction are sizable. Our numerical results show that there exists an obvious mass difference between strange and anti-strange quarks, as large as 10-100 MeV.Comment: 15 latex pages, 3 figures, to appear in PR

    Thermal properties of coal during low temperature oxidation using a grey correlation method

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The low temperature oxidation of coal is a contradictory and unified dynamic process of coexisting mass and heat transfer. The thermophysical properties are crucial during coal spontaneous combustion. In the current paper, the variations of moisture, ash, volatiles, fixed carbon and thermophysical properties (thermal diffusivity, specific heat and thermal conductivity) of three coal samples from 30 °C to 300 °C were studied, and their grey correlation was analyzed. The results indicated that with the increase of temperature, the free moisture of Coals A and B decreased first but then increased, while the free moisture of Coal C kept decreasing without a later increase. The variation of surface moisture was consistent with that of free moisture. The trend of volatiles and fixed carbon was completely the opposite, showing a significant negative correlation. Ash was less affected by temperature. Along with the rise of temperature, the thermal diffusivity of three coal samples decreased first but later increased, and the specific heat was always in a state of increasing. The change in thermal conductivity was mainly affected by specific heat. By calculating the gray correlation degree, the major factors affecting the thermophysical properties were obtained

    On Two-Body Decays of A Scalar Glueball

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    We study two body decays of a scalar glueball. We show that in QCD a spin-0 pure glueball (a state only with gluons) cannot decay into a pair of light quarks if chiral symmetry holds exactly, i.e., the decay amplitude is chirally suppressed. However, this chiral suppression does not materialize itself at the hadron level such as in decays into π+π\pi^+\pi^- and K+KK^+K^-, because in perturbative QCD the glueball couples to two (but not one) light quark pairs that hadronize to two mesons. Using QCD factorization based on an effective Lagrangian, we show that the difference of hadronization into ππ\pi\pi and KKKK already leads to a large difference between Br(π+π){\rm Br} (\pi^+\pi^-) and Br(K+K){\rm Br}(K^+K^-), even the decay amplitude is not chirally suppressed. Moreover, the small ratio of R=Br(ππ)/Br(KKˉ)R={\rm Br}(\pi\pi)/{\rm Br}(K\bar K) of f0(1710)f_0(1710) measured in experiment does not imply f0(1710)f_0(1710) to be a pure glueball. With our results it is helpful to understand the partonic contents if Br(ππ){\rm Br}(\pi\pi) or Br(KKˉ){\rm Br}(K\bar K) is measured reliably.Comment: revised versio

    In vivo impact of a 4 bp deletion mutation in the DLX3 gene on bone development

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    AbstractDistal-less 3 (DLX3) gene mutations are etiologic for Tricho-Dento-Osseous syndrome. To investigate the in vivo impact of mutant DLX3 on bone development, we established transgenic (TG) mice expressing the c.571_574delGGGG DLX-3 gene mutation (MT-DLX3) driven by a mouse 2.3 Col1A1 promoter. Microcomputed tomographic analyses demonstrated markedly increased trabecular bone volume and bone mineral density in femora from TG mice. In ex vivo experiments, TG mice showed enhanced differentiation of bone marrow stromal cells to osteoblasts and increased expression levels of bone formation markers. However, TG mice did not show enhanced dynamic bone formation rates in in vivo fluorochrome double labeling experiments. Osteoclastic differentiation capacities of bone marrow monocytes were reduced in TG mice in the presence of osteoclastogenic factors and the numbers of TRAP(+) osteoclasts on distal metaphyseal trabecular bone surfaces were significantly decreased. TRACP 5b and CTX serum levels were significantly decreased in TG mice, while IFN-γ levels were significantly increased. These data demonstrate that increased levels of IFN-γ decrease osteoclast bone resorption activities, contributing to the enhanced trabecular bone volume and mineral density in these TG mice. These data suggest a novel role for this DLX-3 mutation in osteoclast differentiation and bone resorption

    Superparamagnetic graphene quantum dot as a dual-modality contrast agent for confocal fluorescence microscopy and magnetomotive optical coherence tomography

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    A magnetic graphene quantum dot (MGQD) nanoparticle, synthesized by hydrothermally reducing and cutting graphene oxide-iron oxide sheet, was demonstrated to possess the capabilities of simultaneous confocal fluorescence and magnetomotive OCT imaging. This MGQD shows low toxicity, significant tunable blue fluorescence and superparamagnetism, which can thus be used as a dual-modality contrast agent for confocal fluorescence microscopy (CFM) and magnetomotive OCT (MMOCT). The feasibility of applying MGQD as a tracer of cells is shown by imaging and visualizing MGQD labelled cells using CFM and our in-house MMOCT. Since MMOCT and CFM can offer anatomical structure and intracellular details respectively, the MGQD for cell tracking could provide a more comprehensive diagnosis. This article is protected by copyright. All rights reserved
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